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1. At the beginning of each survey or when re starting a survey from the main menu a warning is momentarily displayed if post processing is disabled If you DO want to store DGPS data press 1C and enable post processing from the GPS menu Otherwise continue with the current settings when the warning message disappears SCREEN D28 GPS WARNING storing for post processing disabled After the survey the DGPS binary data can be transferred to a PC using A send raw data SCREEN D29 GPS yes 8544455 bytes A send raw data F ok C change GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 123 GSM19 Series Magnetometers Version 7 SCREEN D30 A PC transfer B binary transfer 8544455 bytes 1 B binary transfer sends the DGPS data in hexadecimal format and NOT in the normal ASCII The receiving device whether a PC or data logger must be capable of receiving and capturing binary data While this worked well with 2 or 3 MB files the Windows environment proved to be unreliable for larger files DGPS binary files may be much larger than 2 or 3 MB and in those cases part of the data was lost during the transfer even at low transmission rates The PC transfer method is highly advised 2 PC transfer GEMLinkW s Receive DGPS Binary Utility has been designed to safely transfer the DGPS binary data from the memory of GEM Systems magnetometers equipped with on board GPS and with
2. It must be mentioned here that the AC filter is not a DSP digital signal processor implemented in software or a hardware filter It simply shortens the measuring time to match a specific numbers of 1 60 or 1 50 seconds periods to minimize the interference of power lines GEM Systems magnetometers output real measured values with no extra filtering averaging or signal manipulation of any kind State of the art measuring algorithms and system design from the sensors to the electronics ensure the quality of the results In the few cases when averaging of the readings is required you have full control over the process 5 3 10 Setting the Display Mode In the Survey Menu press F to highlight Display Mode SCREEN 26 survey mode position time file cycle time tuning AC filter UNJA nG text ID C change USE gt C change toggles between the text or graph selections If you select text all of the graphs are disabled and the following screen is displayed SCREEN 27 text display mode F ok C change GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 43 GSM19 Series Magnetometers Version 7 If graph is selected the following is displayed SCREEN 28 graph no text display mode F ok C change C change toggles line 2 between no text field n coordinates andfield nT amp coordinates no text only a graph of the magnetic field is displayed during survey with no oth
3. C change allows a change of ID number of this unit value is shown in the headers of the files when using SEND A maximum of 9 digits is allowed This setting has no effect on the readings or the survey mode itself It could be used to identify the operator or any other additional information pertinent to the current file or unit GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 47 GSM19 Series Magnetometers Version 7 5 4 WORKING WITH MOBILE MODE ALL MODELS As described in the instrument description section in Chapter 4 GEM s ROVER modes include mobile gradiometer walking and walking gradiometer This section describes the mobile mode that along with the BASE STATION mode is a standard feature of all GSM 19 series units 5 4 1 Performing a Reading Mobile mode is a standard mode and is always included in every GSM 19 configuration CAUTION Before taking a reading check to make sure all cables and sensor s are connected This maximizes the lifespan of your system and protects internal RF circuits from water damage overheating etc With MOBILE survey mode selected press A start from anywhere in the Survey Menu SCREEN 33 Suave position time file cycle time tuning AC filter display mode text ID connect sensor now 029127 readings left mobile A start C change lt MUWM gt e If tune initialize is selected see section 5 3 7 the unit displays Please
4. D 1 SETTING UP THE GPS To access the GPS menu press F GPS from the Main Menu SCREEN DI A survey B diurn cor F GPS C info OF off D test no 15 II 00 E time synch 1 send TU 00 56 56 45 erase 2 enter text 13 2V Press C change to toggle GPS on or off SCREEN D2 GPS yes 0 bytes A send raw data C change GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 105 GSM19 Series Magnetometers Version 7 NOTE A send raw data and the number of bytes is only visible on mags equipped with DGPS post processing option Press F ok after making your choice e If GPS no is selected the software automatically returns to the Main Menu e If GPS yes is selected the unit displays the GPS menu SCREEN D3 GPS menu A initialize GPS B navigation C synch to UTC D test E post processing no NOTE E post processing is only visible on units equipped with DGPS post processing option B navigation is only visible on units equipped with lane guidance and waypoints navigation options Select A initialize GPS to initialize the GPS module and start GPS lock SCREEN D4 please wait for pps The message please wait for pps where pps represents Pulse Per Second is displayed until GPS lock occurs Then the display returns to the GPS menu GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 106 GSM19 Series Magnetometers Version
5. Select survey mode SCREEN D20 A mobile B Base C grad D walkmag E walkgrad To select the position system highlight position scrolling the cursor with B or F The current position is displayed in the selected system SCREEN D21 survey mode SYNUM time file cycle time tuning AC filter display mode text ID 0000268 0001 0002 629229 4857218 07 A start C change Where 0000268 is the distance in meters along the current line wpl wp2 direction in this example from current location to the ending waypoint wp2 in this example 0001 0002 are the current waypoints 620229 4857218 are the current coordinates GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 119 GSM19 Series Magnetometers Version 7 07 is the number of satellites in view gt are the lane guidance indicators If GPS lock is lost while in the survey menu the screen displays SCREEN D22 survey mode SYNGE time file cycle time tuning AC filter display mode text ID 0000268 0001 0002 no GPS A start C change Press C change to change the positioning system SCREEN D23 survey mode SYNGE time file cycle time tuning AC filter display mode text ID 0000268 0001 0002 629229 4857218 A start C change SCREEN D24 select position system rotated grid F ok C change The options are Local Grid Rotated Grid UTM or Lat Long GEM Systems Inc Advanced Magnetometers
6. E for Enter stores the changes Once all the programs have been entered press A start to begin the survey The unit searches through the programs until it finds the first to run If the start time of the program has already passed the unit starts immediately Otherwise it displays SCREEN G13 050916 waiting for program 01 020503 07 00 020504 23 00 Where 050916 is the current time in hhmmss 020503 07 00 are start date and time of the program 020504 23 00 are stop date and time of the program When the start time is reached the survey begins NOTE The start time indicates the beginning of the survey and NOT the time of the first reading Depending on the selected cycling rate the time of the first reading of the file is delayed Furthermore to preserve the battery the GPS module is turned off while waiting for a program start If GPS is enabled the unit turns on GPS and waits for GPS lock and UTC synchronization This further delays the time required for the first reading At the stop time the unit stops cycling turns off GPS if enabled and closes the current file If another valid program is stored the unit waits for its start time When all the programs are completed the unit displays a press 1C message GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 146 GSM19 Series Magnetometers Version 7 L5 TRANSFERRING SCHEDULES FROM YOUR PC TO YOUR GSM 19 By selecting D
7. GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 60 GSM19 Series Magnetometers Version 7 5 6 1 Performing a Reading After the initial start up procedures refer to section 5 3 select the survey mode from the Survey Menu as follows SCREEN 53 SUA SENSE position time file cycle time tuning AC filter display mode text ID connect sensor now 029127 readings left mobile A start C change a gt Press C change The following screen is displayed SCREEN 54 A mobile B base C grad D walkmag E walkgrad In this screen you have the choice of selecting the Survey Mode D for walkmag mode available on GSM 19W units E for walkgrad mode available on GSM 19GW units Both walkmag and walkgrad are auto cycling modes The unit takes readings at the pre set rate without your intervention and as he she walks along the lines To set the rate highlight cycle time from the survey menu and use C or B to increase or decrease the current setting The available rates are 0 5sec 2 readings second or 2Hz 1 0sec 1 reading second or 1Hz 2 0 sec 1 reading 2seconds or 0 5 Hz GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 61 GSM19 Series Magnetometers Version 7 NOTE Some units normally the models GSM 19F fastmag or GSM 19GFW fastgrad are equipped with 0 2 sec 5Hz Press A start when ready to start the
8. GSM 19 version 6 magnetometers are equipped with flash memory chips Flash memory cannot be partially erased The technology requires that the memory chips must be erased all at once For this reason it is not possible to remove single files from the memory To erase one file you must erase them all When flash memory is erased all the information is overwritten with blanks Once erased the data CANNOT be recovered IMPORTANT NOTE Use this function only if you want to clear the entire memory since all of the files is erased As a security feature to prevent accidental data loss you must press two buttons simultaneously to access the erase menu and to later confirm whether to erase the memory or not 8 1 STARTING THE ERASING PROCESS From the Main Menu press 4 and 5 simultaneously SCREEN 86 erase data er erase n NO e If you choose to NOT ERASE press n NO button 6 The system returns to the main menu e To erase data simultaneously press the e andr 3 and 7 buttons The unit displays the percentage of memory erased as the process progresses GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 84 GSM19 Series Magnetometers Version 7 SCREEN 87 please wait 010 of memory erased Press F when 100 of the memory has been cleared NOTE Units with 32MB of memory take several minutes to erase all memory GEM Systems Inc Advanced Magnetometers For more te
9. Version 7 Press F ok to continue or C change number again to make more changes On the next screen you can enter the terrain slope and its direction which is stored with the VLF data SCREEN C5 0000N slope elevation 0 8191 B change NESW F ok C change number If you are satisfied with your selection press F ok This leads you to the Survey Menu corresponding to the current survey mode SCREEN C6 JAGAN position time file cycle time tuning AC filter text ID connect sensor now 018127 readings left mobile vlf A start From the survey menu you can adjust the parameters in the usual way Common parameters such as position file name or time apply to both the magnetic and the VLF surveys NOTE VLF readings are taken after the magnetic readings Remember that when combined with walk modes the VLF readings are not taken while walking Instead when F is pressed to mark a station label the unit interrupts the cycling takes the VLF reading and then prompts you to reassume the cycle GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 101 GSM19 Series Magnetometers Version 7 C3 STARTING A READING Press A start to start the survey The VLF readings are presented as on the following screen SCREEN C7 24 0 kHz 005 6 pT 1 022 1 0 014 2 p053 v 024 A menu repeat same position L00100N 500112 50E Each Station will have 6 Values displayed Frequency in kHz b
10. no differential C CDGPS W SBAS and O OmniSTAR solution date and time If GPS initialized for OmniSTAR without subscription letter O will be visible on the screen but positioning provided will not be up to specified Third line UTM zone UTM coordinates and elevation in meters above sea level Fourth line Local Grid Coordinates Fifth line Rotated Grid Coordinates Six line shows standard deviation of Easting Northing and Height in meters Seventh line shows selected datum Bottom line has Latitude and Longitude along with number of satellites being tracked at the moment Pressed F button will lead to GPS menu 7 Change of Datum Factory default geodetic datum for OEMV 1 is WGS84 Operator can select from 86 available Datum s Table 3 List of available Datum s Courtesy of NovAtel 1 ADIND See 65 2 ARCS50 ARC1950 SW amp SE Africa 3 ARC60 See 66 4 AGD66 Australian Geodetic Datum 1966 5 AGD84 Australian Geodetic Datum 1984 6 BUKIT Bukit Rimpah Indonesia 7 ASTRO Camp Area Astro Antarctica 8 CHATM Chatham 1971 New Zealand GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 133 GSM19 Series Magnetometers Version 7 9 CARTH Carthage Tunisia 10 CAPE CAPE
11. Column 3 Signal Quality GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 94 GSM19 Series Magnetometers Version 7 B 3 VLF OPTION If you select A all from the Send Menu i e to transfer all VLF data the format is as follows 141645 0 0000N 0000100E 57137 66 57001 37 000N 21 4 006 0 000 9 071 026 005 6 24 0 013 4 001 1 000 090 012 1 23 4 027 7 003 1 004 066 000 5 141645 0 Time as hhmmss s 0000N Line number and direction 0000100E Station number and direction 57137 66 Uncorrected magnetic field nT 57001 37 Corrected magnetic field nT 000N Slope degrees 2 4 First VLF station frequency 006 0 ip vertical in phase component 000 9 op vertical out of phase component 96 071 X horizontal amplitude 026 y horizontal amplitude 005 6 VLF total field strength pT 24 0 Second VLF station frequency 013 4 ip 26 001 1 op 26 000 x amplitude 090 y amplitude 012 1 VLF total field strength pT The next six numbers represent the same values for the third VLF station GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 95 GSM19 Series Magnetometers Version 7 It is also possible to send only the magnetic field readings without any VLF readings Enabling the F field option in the send menu does this The resulting data appears as follows corrected time line station field nT field nT 141545 0 00000N 0000
12. Field strength in pT i In phase component as a percentage of the field strength o Out of phase component as a percentage of the field strength p Horizontal component coil axis parallel to the operator s direction arbitrary scale v Horizontal component coil axis at the right angle to the operator s direction arbitrary scale The last line displays the position coordinates in the form of the current positioning system When conducting the survey with the VLF option on the GSM 19 the quality of the incoming signal can be effectively determined by the field strength shown in the upper right corner of the screen This value is directly proportional to the strength of the incoming signal A field strength reading above 5pT yields excellent quality results Below this level the readings still give useful results although of lesser quality A field strength reading of less than 0 5pT indicates a VLF signal so weak the results are not useable To conduct a useful survey of an area you should tune into a station with the highest possible total electromagnetic field reading To determine the field strength of the stations you can use the Scan option The Scan option gives you a general view of the available VLF spectrum The entire VLF range is scanned and all stations of sufficient strength are displayed along with their signal strength in pT or mgamma GEM Systems Inc Advanced Magnetometers For more technical information visit
13. For more technical information visit www gemsys ca 120 GSM19 Series Magnetometers Version 7 NOTE When using programmable waypoints the Local and Rotated Grid options may not be displayed If they are displayed however remember that the waypoints are entered in UTM and therefore Local or Rotated systems are not coherent with the planned route Other survey parameters may be adjusted as normal When ready press A start to start the survey and take magnetic readings The unit will 1 Check GPS lock and initialize GPS if necessary 2 Synchronize internal clock to UTC time time is overwritten 3 Perform tune initialize for magnetic readings if tune initialize is enabled 5 Display the reading menu The GPS information is displayed along with the magnetic data For example in the Mobile mode you see SCREEN D25 48101 65nT 0 01 A menu other keys read 12 2 0000268 0001 0002 629229 4857218 07 Where 0000268 is the distance in meters along the current line wpl wp2 direction in this example from current location to the ending waypoint wp2 in this example 0001 0002 are the current waypoints 629229 4857218 are the current coordinates 07 is the number of satellites in view gt are the lane guidance indicators GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 121 GSM19 Series Magnetometers Version 7 NOTE When GPS is enabled it is not
14. Point to Point Navigation By selecting B programmable waypoints the survey can be planned almost Point by Point Up to 1000 survey waypoints can be stored in memory and the unit guides you to each one of those points While walking from waypoint to waypoint the lane guidance feature keeps you within a lane of pre defined width using arrows lt or gt to indicate left or right When within the lane the display shows horizontal bars In addition the distance in meters to the next waypoint is displayed In contrast to the automatic grid Programmable Waypoints is a Point to Point navigation mode NOTES The coordinate of the waypoints can ONLY be entered in UTM The points are retrieved from memory in ascending numeric order If the survey starts at WP1 you are guided to WP2 Then from WP2 to WP3 and so on When the indication of the distance to the waypoint is zero meters and the arrows are not displayed you reached destination At this point you should exit the reading mode using A menu and then use the command E next point The next point command is used and works as the EOL command It basically switches the destination point as the origin point and retrieves the next consecutive waypoint from memory The next figure shows these concepts GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 113 GSM19 Series Magnetometers Version 7 L NORTHING PRESS E ne
15. S lt D O oc g m o ud c be a 8 o b E 2D P c Oo m a a t 8 oD 5 n 5 3 wd 270 240 210 Figure A2 Magnetic Field Inclination GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 93 GSM19 Series Magnetometers Version 7 APPENDIX B RAW DATA FILES TRANSMITTED BY RS 232 C Data is sent via the unit s serial link to a printer or a host computer in a standard ASCII format The data comes as a stream of unlabelled numbers that varies with the survey mode that was employed Slow modes have a more extensive header including column identifiers Each case is described below B 1 MOBILE MODE Data taken in mobile mode is sent through the Rs 232 port as follows corrected time line station field nT field nT 122136 0 00000N 0000100E 57034 56 56977 87 99 122142 0 00000N 0000125E 57034 67 56977 84 99 Column 1 Time as hhmmss s 12h 21m 36 0s in row 1 Column 2 Line number and direction Column 3 Station number and direction Column 4 Raw unreduced data nT Column 5 Reduced magnetic field data nT Column 6 Signal Quality B 2 BASE MODE Base station data transmission is similar to that of mobile data except for the exclusion of line and station numbers The transmission appears as follows time field nT 125010 0 57756 28 99 125020 0 57756 12 99 Column 1 Time as hhmmss s Column 2 Unreduced magnetic field data nT
16. Table 1 L band Signal Tracking Status Courtesy of NovAtel n 0x0001 Tracking State 0 Searching 1 Pull in 2 Tracking 0x0002 ox0008 0x0008 Reserved ox0070 0x0020 6 0x0040 Bit Timing Lock 0 Not Locked 1 Locked 0x0080 0 Not Locked 1 Locked 8 0x0100 DC Offset Uniocked 0 Good 1 Waming 9 0x0200 AGC Unlocked 0 Good 1 Waming 0 0400 0x0800 Reserved ox1000 0x2000 ria ouo GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 130 GSM19 Series Magnetometers Version 7 Eight line represents OmniSTAR VBS Status Word Screenshot 6 of magnetometer screen above shows that subscription expired For more detailed explanation please refer to Table 2 Table 2 OmniSTAR VBS Status Word Courtesy of NovAtel 0x0001 Subscription Expired True 0x0002 Out of Region True a 3 ooo True x0100 Reserved 4 5 0 x0200 z N x0400 x0800 x1000 x2000 z x4000 x8000 Updating Data a Contact OmniSTAR for subscription support All other status values are updated by collecting OmniSTAR data for 20 35 minutes Howe ENLLCNI ne 4 oor S o e o0 s ooo 9 om0 10 osoo 1t oso 4 osoo as oxsoo0 Press F button to get to GPS menu 4 L band info To verify current status of L band based services as OmniSTAR or CDGPS from GPS menu press 0 Lband info One of above shown screens 4
17. Version 7 Select C grad The following screen is displayed This screen enables you to define settings for the gradiometer mode SCREEN 46 AGAn position time file cycle time tuning AC filter display mode text ID sensors connect sensors now 029127 readings left grad A start C change 5 5 2 Specifying Gradiometer Sensor Spacing Press F to highlight sensors The following screen is displayed SCREEN 47 survey mode position time file cycle time tuning AC filter display mode text ID ayers 56 cm apart A start C change NOTE This screen is available only with the gradiometer models C change allows you to set the distance between sensors The change is allowed only once per file before the first reading is taken Grad displayed is in nT m and is obtained as Gradient nT m FIELD lower channel nT FIELD upper channel nT Distance between sensors m If just the difference of the two fields is required enter 100cm as the distance between the sensors GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 57 GSM19 Series Magnetometers Version 7 5 5 3 Selecting the Display Mode Press F to highlight display mode The following screen is displayed SCREEN 48 survey mode position time file cycle time tuning AC filter display mode text ID sensors graph A start C change Use C change to switch to the text or graph modes In graph mode you can plot either th
18. see section 5 4 5 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 50 GSM19 Series Magnetometers Version 7 5 4 2 Repeating a Reading To repeat a reading make sure that you are in the Reading Menu and press 1 repeat The following screen is displayed SCREEN 37 56 789 34 nT 12 34 nT A menu 1 repeat same position other keys read L 100 N S 200 The new reading has the coordinates of the current position either Line and Station numbers or X Y coordinates You can take as many repeated readings as needed 1 e without incrementing the position by pressing 1 repeat same position ALL repeat readings are automatically stored with the same coordinates and the actual time of the reading When you dump or transfer the file using SEND all the readings and the repeats are sent with their correct time stamp and coordinates NOTE On units equipped with GPS it is not possible to take repeat readings when GPS is active The coordinates are taken from the GPS module each time a reading is taken 5 4 3 Monitoring the Noise From the Reading Menu press A menu The following screen is displayed SCREEN 38 A position B enter text 4 graph vertical scale C tune 5 display mode E EOL F OK O noise info GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 51 GSM19 Series Magnetometers Version 7 Then press 0 noise SCRE
19. the external triggering of the unit by the RS 232 line may not work properly or at all since the transmission rate is not initialized see end of section 4 3 6 2 2 Transferring the Data For proper data transfer you MUST match the RS 232 settings of the magnetometer and those of the receiving device PC data logger etc Remember that you can program the transmission rate for SEND and RTT on the unit However the data bits stop bits and parity are not programmable for either SEND or RTT but the default values are displayed on the setting screens for your reference GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 74 GSM19 Series Magnetometers Version 7 NOTES You MUST set the receiving device to these parameters 8 data bits 1 stop bit no parity You will need an RS 232 cable 6 pin to 9 pinD cable Please contact GEM Systems to order one To start the transfer 1 Connect the 9 pinD connector to an available serial port on the receiving device and the 6pin connector to the unit 2 Then from the Main Menu press 1 Send to dump or transfer the data The system displays Screen 70 SCREEN 70 file F ok C change number e If there is only a single file in the memory the system automatically shows screen 71 e If there is more that one file in the memory you are prompted to select the file you want to transfer If the file number shown in the screen ex 2 above
20. there may be a time discrepancy between the two units This time discrepancy only becomes significant after very long surveys or in the case of unattended base stations without GPS GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 65 GSM19 Series Magnetometers Version 7 e Ifnone of the units is equipped with GPS set the time manually in one of them and use the synch cable to transfer the time to the other In this case both units run on their respective internal timers 5 8 2 Transferring the Time To transfer the time from the Main Menu press E time synch on EACH unit The following screen is displayed SCREEN 57 connect cable amp press C Connect the 6 pin to 6 pin cable between the two units NOTE The same cable is used for diurnal correction This is why sometimes it is called Reduction Cable and sometimes Synch cable Please contact GEM Systems if you need to order one Press C The following screen is displayed SCREEN 58 A source B destination enter destination first GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 66 GSM19 Series Magnetometers Version 7 First press B destination on the unit with the incorrect time and then press A source on the unit with the correct time After the synchronization the destination unit displays screen 59 while the source unit displays screen 60 SCREEN 59 SCREEN 60 04
21. 14400 19200 28800 38400 57600 152000 A select Scroll backward with B or forward with F and highlight the desired transmission rate keep pressed for a continuous scroll Press A select to save your option The unit returns to screen 66 Pressing F ok leads you to the selection of RS 232 parameters for Real time Transmission RTT When RTT is enabled the unit outputs the readings tagged with their time stamp to the RS 232 6 pin connector in real time as they are taken SCREEN 68 real time RS 232 transmission yes F ok C change C change toggles between yes and no e If you do not intend to use the RTT function select no and press F ok to return to the Info Menu Then press 1C to return to main menu e Otherwise select yes and press F ok The RTT setting screen is displayed GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 73 GSM19 Series Magnetometers Version 7 SCREEN 69 19200 28800 38400 57600 115200 A select Press A select to save your option If finished press F ok to return to the Info Menu and then press 1C to return to main menu IMPORTANT NOTES The data bits stop bits and parity are not programmable for either SEND or RTT but the default values are displayed for your reference You MUST set the receiving device to these parameters 8 data bits 1 stop bit no parity The slowest transmission rate for RTT is 19200 bps If RTT is not enabled
22. 38 GSM19 Series Magnetometers Version 7 C change enables you to change the 6 letter file name but only before the first reading of the file e Use the red letters on the keyboard to name the file If the required letter is second or third press the corresponding button twice or three times Use the F X button after each letter to move the cursor to the next position and B X button as a backspace You can store up to 50 files in the mag File names have a format similar to Olsurvey m where you can only change the 6 letters between the first number and the period i e the file extension is fixed The prefix numbering ex 01 to 50 and the file extension are automatically assigned The file extensions are m for mobile and b for base see section 6 1 for more file extensions 5 3 7 Setting the Cycle Time In the Survey Menu press F to highlight cycle time SCREEN 20 survey mode position time file tuning AC filter display mode text ID 0004 0 sec cycle time A start C D Iu o C and D enable you to decrement or increment the Cycle time There are four groups of survey modes with different limits in cycle time Cycle Time Survey Mode 3 0 sec 10 0 sec Mobile gradiometer mobile vlf gradiometer vlf 3 0 sec 3600 0 sec Base Station 0 5sec 2 0 sec Walk modes 0 2 sec 2 0 sec Fast amp marine modes The cycling time for each of these groups is saved and after changing the survey mode
23. 6 Pin Connector The 6 pin connector can be used for different purposes e To connect the charger e For time synchronization and for diurnal correction use 6 pin to 6 pin cable connected from console to console e For RS 323 data transfer either in Real time Transmission or after the survey e For external triggering e For upgrading internal software e For any combinations of the above with proper cable contact GEM systems for available options Figure 5 Operator with console sensor and GPS GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 22 GSM19 Series Magnetometers Version 7 4 3 DESCRIPTION OF CONNECTORS C SNSR Sensor Channel that receives the proton precession signal RS232 RS 232 Communication port PWR and input for power GSM 19 MAGNETOMETER O SNSR Sensor channel that receives the proton precession signal O PLRZ Polarization sends RF signal polarizes the sensor C RS232 RS 232 Communication port PWR and input for power GSM 19W WALKING MAG Upper sensor channel that receives the proton precession signal LWR Lower sensor channel that SNSR receives the proton precession signal RS232 RS 232 Communication port PWR and input for power GSM 19G GRADIOMETER O UPR Upper polarization PLRZ Sends RF signal polarizes the upper sensor UPR Upper sensor channel that
24. II 95sa12 02 21 3 04 II 95sa12 02 21 3 C or 1C C or 1C synch done 4 1ms You is able to check the time by pressing the C button on both mags simultaneously This freezes the time on the display for an easier comparison but the internal timer continues running Press 1 C to return to main menu After the aforementioned steps time synchronization can be inspected again at any time and on both mags To do so from the Main Menu press C info and then press F time Press and hold the F key simultaneously on both units to freeze the time display 5 9 APPLYING DIURNAL CORRECTIONS Diurnal corrected data is obtained by combining the readings of a Mobile unit with the readings of a Base Station unit The diurnal correction is obtained from the following equation corrected field mobile field base field datum The Datum is just a positive shift of the corrected data It is normally set to the average or expected magnetic field of the area but it could also be set to any other positive value or to zero Since the Base is a stationary unit its changes of the magnetic field are only caused by diurnal variations The readings of the Mobile unit however are influenced by the diurnal and also by the local variations of the field encountered during the survey anomalies The Diurnal Correction removes the diurnal variations from the Mobile data so the anomalies can be better appreciated The reference or criteria to combine the Mobile and Ba
25. Magnetometers Version 7 3 EARTH S MAGNETIC FIELD The nominal distribution of the Earth s magnetic field is shown in Figure Al in Appendix A and the separation of equatorial and polar regions is shown in Figure A2 In polar regions the inclination of the magnetic field vector is approximately vertical whereas in equatorial regions it is horizontal In general the sensor axis must be approximately at right angles to the magnetic field to obtain the best signal For this purpose the sensor must be kept oriented in a magnetic East West direction in equatorial regions NOTE Omnidirectional sensors i e do not need to be oriented can be purchased as an option from GEM Systems Initially the tuning of the instrument should agree with the nominal or expected value of the magnetic field for the particular region see Figure Al in Appendix A You can set this tuning automatically or use the tune initialize feature provided for this purpose After each reading the instrument tunes itself automatically If large changes in magnetic field are encountered between successive readings you see a warning and you may have to repeat the reading to obtain an accurate result Local ferromagnetic objects such as screws pocketknives wristwatches tools etc may impair the quality of measurement or in drastic cases obscure the proton precession signal by creating excessive gradients NOTE For best results you should keep ferromagnetic ob
26. RS 232 the base schedules can be transferred to the unit from a PC file This is not a different base survey mode It is actually a tool to enter the base schedules If you need to enter several base programs it may be easier to type them into a text file on a PC and then transfer the file to the unit using the RS 232 port NOTE To transfer the base schedules you MUST have GEMLinkW 2 4 or newer installed on your PC and use the programmable Base utility GEM LinkW is freely available from GEM Systems web site The text files may be created using GEMlinkW in editing mode or with any other word processor capable of saving as plain ASCII text Spreadsheet programs such as Microsoft Excel can also be used provided the files are saved as text space comma TAB or colon separated and not as worksheets or workbooks The magnetometer consoles can store up to 30 programs or schedules Therefore the files should have 30 or less lines or rows However if the file is larger only the first 30 lines is transferred The end of each line is determined by a CR carriage return or CRLF carriage return line feed Lines terminated only with LF cannot be used since they are treated as a single line A general condensed description of the file format may be written as follows Start date and time Stop date and time YYMMDDhhmm prog 1 Separator YYMMDDhhmm prog 1 CRLF YYMMDDhhmm prog 2 Separator YYMMDDhhmm prog 2 CRLF YYMMDDhhmm prog 30 S
27. ca 49 GSM19 Series Magnetometers Version 7 To Stop Reading or Exit the Reading Menu press A The following screen is displayed SCREEN 36 A position B enter text 4 graph vertical scale C tune 5 display mode E EOL F ok 0 noise info The following menu gives you access to some of the parameters in the set up menus e A position Will take you to the position coordinates setup screen NOTE that from this menu you can only change the coordinates but you cannot change the system see section 5 3 2 e B enter text Allows you to type messages or comments which can later be recovered with SEND e 4 graph Is active only if graph mode is selected It allows to change the graph s scale and offset see section 5 3 8 e C tune Leads you to the tuning setup screens see section 5 3 6 NOTE that the tune initialize process is not repeated when returning to survey even when set to YES e 5 display mode Guides you through the selection of Display Mode see section 5 3 8 e E EOL Performs End Of Line function line number is incremented direction is reversed see section 5 4 4 e F ok Takes you back to survey e 0 noise Will display noise from sensor value of 100 or less is normal see section 5 4 3 e 1 info Is very useful in providing information about last reading like s n signal noise ratio and measurement time in ms It also shows the number of readings which can be taken before the memory is full
28. current version is 3 0 The instructions here correspond to the 2 4 software release If any of the steps don t match the options or screens available from your unit it is either because your unit does not support the waypoint feature or you have an older software version Please contact GEM Systems for assistance D 5 SURVEYING WITH GPS NAVIGATION IMPORTANT NOTES The GPS antenna must be connected to the BNC connector MARKED WITH YELLOW located on the RIGHT HAND SIDE of the console Do NOT connect the GPS antenna into the BNC connector for the sensor RF on the left hand side The antenna will be damaged beyond repair The GPS antenna MUST be mounted a minimum of one full section staff 56cm apart from the sensors to avoid magnetic interference Make sure GPS is enabled GPS yes When the GPS is enabled the positioning system is selected as usual but the options are different Press A for survey and using the F control to toggle the cursor right to Position press C to change The following sequence is an example From the Main Menu press A survey The following screen is displayed SCREEN D18 A survey B diurn cor F GPS C info OF off D test yes 15 II 00 E time synch 1 send TU 00 56 56 45 erase 2 enter text 13 2V The unit checks for GPS lock GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 118 GSM19 Series Magnetometers Version 7 SCREEN D19 please wait for pps
29. is not the file you want to transfer select C change number The system displays a file entry screen Enter the file number and then select E Enter The system then returns to Screen 70 where you now select F ok The system displays Screen 71 SCREEN 71 Select SEND format D Default F Custom Screen 71 is new functionality developed for Version 7 This screen allows you to either select a default file format or your own format See Appendix H for a description of data values for each format GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 75 GSM19 Series Magnetometers Version 7 When you select D Default the system automatically starts sending data When you select F Custom the system displays Screen 72 SCREEN 72 SEND format is X Y elevation nT nT m sq cor nT sat time picket x picket y A send C Change 1 To alter the order of data values position the cursor on the field that you want to change and press C The system scrolls through a series of values 2 Choose the one that you want and either move to the next field or select A send to start transmitting the data GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 76 GSM19 Series Magnetometers Version 7 7 RECALLING DATA The GSM 19 series of magnetometers gradiometers enables you to recall or review data in text mode and graphical mode This system describes t
30. on the mobile grad walk walkgrad unit If there is more than one file in memory select the relevant one and press F ok If the mobile is the version 6 unit it displays SCREEN 64 connect cable and set base mag to main menu 5 Press F 6 The software automatically searches the base for the file with the correct date and time and transfers its data 7 Press 1C to return to the main menu Version 5 and version 6 magnetometers are fully compatible for unit to unit diurnal correction whether they are used as Base or Mobile Older units however may not be fully compatible with the version 6 magnetometers but you can always perform file to file correction using GEMLinkW NOTE When units older than version 5 are in use it is advised to use File to File correction This is because in the event of incompatible file formats the original mobile file may be damaged when combined with the base file GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 69 GSM19 Series Magnetometers Version 7 5 9 2 File to File Diurnal Correction GEMLinkW Utility If you have GEMLinkW installed in your computer you may use its Diurnal Correction Utility to combine the Base and Mobile files after you saved them on a disk Please refer to the help files provided with GEMLinkW for more information NOTE GEMLinkW is normally shipped with the new units in a CD ROM It is also available from GEM Systems W
31. possible to take repeat readings Each reading is taken with its UTC time and its coordinates If GPS lock is lost during the survey the unit displays SCREEN D26 48101 65nT 0 01 A menu other keys read 12 2 0000268 0001 0002 No GPS NOTES Automatic Grid Setup line to line navigation does not display distance to the destination point Other survey modes display the navigation data in a similar fashion D 6 DGPS POST PROCESSING Units equipped with GPS and post processing option are capable of storing the binary GPS information required for the purpose When the magnetometer is in reading mode the required messages from the GPS module are stored in binary format at the end of the memory block NOTES Since the DGPS information is stored at the end of the memory block it is recommended to erase the entire memory before a survey involving DGPS storing to delete any data from previous surveys Two DGPS files are required to perform GPS post processing One from a base GPS station which could also be the mag base station and another from the mobile unit To enable or disable post processing from the GPS menu press E post processing and conduct the survey in the usual manner GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 122 GSM19 Series Magnetometers Version 7 SCREEN D27 GPS menu A initialize GPS B navigation C synch to UTC D test E post processing no
32. post processing option to a file on the PC Once initiated the process automatically checks for data integrity Checksums of the transmitted and received data and size of the files in bytes are available from the unit and the PC to confirm proper data transfer Step by step instructions are provided with the utility NOTE For this method GEMLinkW 2 4 or higher is required D 7 CDGPS OMNISTAR GPS OPTION 1 Introduction This document provides basic information operator needs to know to setup and begin to use GSM 19 magnetometer equipped with OEMV NovAtel GPS CDGPS option available for GSM 19 magnetometers based on OEMV compact low power single frequency L1 GPS with integrated L band Omni STAR CDGPS card OEMV GPS requires to be initialized on power up each time 2 Enabling GPS On power up from main menu press F GPS button and then enable GPS operation by pressing C change button if it is disabled Once message GPS yes is on the screen GPS is powered up To verify GPS hardware version firmware version please press buttons 5 6 simultaneously GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 124 GSM19 Series Magnetometers Version 7 GEM Systems In different modes of operation GPS OEMV module communicates with magnetometer on two different baud rates 115200 and 9600 After GPS powered up magnetometer attempts to establish communication with GPS on both baud rates
33. that follows a negative value has been used to increment lines below the initial line The system generates a grid with 500 lines i e 1000 waypoints With waypoints you can a use as many of the waypoints as required b skip waypoints for example where obstacles are in the way c stop the survey and re start at another waypoint GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 109 GSM19 Series Magnetometers Version 7 If you have the lane guidance option selected you are automatically guided to the next waypoint when you reach the end of the line Alternately you can stop taking readings at a particular point on the line move to the next line and resume your survey at any desired location on the line In addition to the automatic grid generation and lane guidance features the coordinates in this navigation mode can be referenced to a Local Grid or to a Rotated Grid The Local Grid takes as its origin the START point but with arbitrary coordinates assigned by you The orientation of its axes remains parallel to NS and WE directions the same as the UTM coordinates The Rotated Grid uses the same origin and arbitrary coordinates as the Local Grid but the axes are rotated so the Y axis takes the direction of the line The following picture shows how the different systems relate to each other i NORTHING a N LOCAL GRID Y AXIS P LINE O ORIGIN X 20 ENDPOINT ROTATED GRID Y AXI
34. the system displays the lane width screen This is the first step in a process of verifying that the lines created are consistent with the values you want 3 Press F ok in the lane width screen The system displays the waypoint review screen with the first waypoint identifier 1 Press F ok again The system displays the second waypoint identifier 2 Press F ok again The system displays the waypoint 0001 screen 32 Use the waypoint screen to confirm that the easting and northing values are the ones you intended to use At this point you can either continue to check values or press E end to exit from this screen and return to the GPS screen You are now ready to survey 1 1 6 Starting a Reading Surveying and Stopping Recording In this section we quickly review the steps involved in actually acquiring data in walking mode We start with the basic steps and then move to more advanced concepts such as positioning systems and how to use the X Y positioning system 33 From the Survey menu press A start The system displays a please wait message while it initializes the GPS The system then displays the start survey screen This screen has controls for advancing the waypoint currently you see distances to your second waypoint 34 We recommend that you use the A control to decrement the waypoint from 2 to 1 You can then use the navigation arrow and distance fields on the screen to navigate to waypoint 1 where you will start your sur
35. to 99999 STATION 0 to 9999999 or 0 00 to 99999 99 each with NN NE E SE S SW S NW F ok C change C change toggles between the above two screens Press F ok to select one NOTE If your unit is equipped with built in GPS and GPS is active you have more options for the positioning system See Appendix D for more details GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 31 GSM19 Series Magnetometers Version 7 If you select X Y system the next screen is SCREEN 10 x 0 y 0 position x 0 y 0 increment x 0 y 0 EOL increment E next C clear D backsp F ok Position Current coordinates These are the X Y coordinates of the first reading e Increment Increase in each direction that is added to present position after each reading EOL End Of Line increment i e added to the present X and Y if you press EOL see section 5 4 4 A list of available commands is shown on the bottom line E moves cursor to next number C erases the number at cursor position D cursor jumps to the end of the number if you just want to modify last digit F leaves this screen If you press C clear or D backsp the bottom line changes to display new commands SCREEN 11 x 0 position x 0 increment x 10 EOL increment 0 9 A dp B D backsp E enter GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 32 GSM19 Series Magn
36. want to use In this case select UTM 7 Press F ok The system displays the select picket marking screen This is the screen enables you to annotate UTM values in the magnetometer s output file at designated locations What happens with Walking mode is that you can mark pickets at designated stations i e UTM values are added to the file when you press F during the survey For example if you are walking along the grid and reach a picket that you want to identify with specific UTM locations you would then press F at the picket location These values are added to the file 8 If you want to change the marking system press C The system shows the next possible option For now choose the XY option and press F ok when finished The system displays the X Y detailed positioning screen 9 Start by setting the position Here we use x 0 y 0 as the start of our grid you can use any values that are appropriate for your project 10 The increment value controls the data acquisiton locations along the line If your plan for the survey grid is to run vertical lines at 1m spacings move the cursor to the increment values select C clear and then E enter until increments are set to set x20 yz1 When finished select E Enter Alternately ilf your plan is to run horizontal lines set x21 y 0 for instance for the increment 11 The EOL increment controls the line spacing For example if you are using vertical lines and lines spaced at 2m set x 2
37. would try to synchronize to UTC without initialization than message shown on fig will appear on the screen GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 127 GSM19 Series Magnetometers Version 7 3 1 CDGPS initialization If CDGPS mode of operation will be selected then one of four possible Canadian locations must be selected GEM Systems ix select CDGPS A East B East Central C MWezt Central D MWezt Screen 3 A East B East Central C West Central D West Depending on area selection one of four available L band satellites will be used Once location selected then CDGPS will show the status of frequency carriers accordingly to specific satellite Screen 4 1557897000Hz Measured frequency of L band signal GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 128 GSM19 Series Magnetometers Version 7 46 53dB Carrier to noise density ratio 28 85 Number of seconds of continuous tracking 0082 Tracking status Digit 8 stands for Phase Locked Last digit in this example 2 stands for 2 tracking O serching 1 pull in After pressing F console will automatically go to GPS Menu 3 2 SBAS initialization If SBAS initialization option is selected then no other settings are required and console will automatically go to GPS menu 3 3 OmniSTAR initialization If OmniSTAR initialization option selected then o
38. y 0 Or if you are using horizontal lines spaced at 3m set x 0 y 3 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 8 GSM19 Series Magnetometers Version 7 12 Press F ok The system returns you to the Survey menu 1 1 3 Changing Time Filename and Cycling The time parameter controls the clock settings and therefore the time stamps that are placed in the final output file It is also required for performing base station corrections Filename controls the designated name of the file and is generally some specific value that is appropriate for the project at hand ex O5survey m or other value The cycling controls the rate at which the magnetometer or gradiometer samples 13 In the Survey menu move the cursor to the time item and select it using C change Select C change and enter a new time in wyymmddhhmmss format For a description of this format see the corresponding information in the User Guide 14 Move the cursor to the file item and select it using C change Type a new filename and use the E enter key to save the name Note that the first two letters and the extension cannot be altered these are reserved for system defaults 15 Move the cursor to the cycling item and select it using C change The system toggles the cycling settings as shown on the display For walking mode you should see settings such as 0 5 sec 1 0 sec 2 0 sec etc 1 1 4 Setting the Tuning AC F
39. 100E 57138 04 57001 42 141606 0 00000N 0000125E 57137 88 57001 33 Column 1 Time as hhmmss s Column 2 Line number and direction Column 3 Station number and direction Column 4 Uncorrected magnetic field nT Column 5 Reduced magnetic field nT B 4 WALKING MAG OPTION Data obtained with the Walking unit option can be sent in a variety of formats If you select A a11 from the Send Menu the format is as follows 0000N 000100E 101302 0 057070 42 057015 16 101308 0 057069 93 057014 57 Row 1 Line number direction and station number direction Row 2 Column 1 Time as hhmmss s Row 2 Column 2 Uncorrected magnetic field nT Row 2 Column 3 Reduced magnetic field nT NOTE The text in row I only appears chronologically when a position label for a picket was stored GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 96 GSM19 Series Magnetometers Version 7 If you select D station interpolation station numbers are linearly interpolated as follows 0075N 001937 0E 060326 34 0075N 001937 3E 060326 72 0075N 001937 5E 060326 92 Column 1 Line number and direction Column 2 Interpolated Station number and direction Column 3 Uncorrected magnetic field nT NOTES The station number always has an extra digit added to the end for the interpolation If you are planning to use station interpolation for walk files keep in mind the number of readings and the distance between pi
40. 27 3 34 Setting the Survey Mode iiia eae tate egre e eI OE pup pie P Het Pepe 26 3 3 2 Setting the Positioning System e eee qetresietee ee EORR Ie reget ee e ENE Pes denter tds 29 5 3 3 Understanding the Line Station Positioning System eese entree 34 5 3 4 Understanding the X Y Positioning System cesses eene eene ettet nenne nennen nene 35 3 3 Setting the ime iu siio e e Roe Me er e ee RR cost Ae E eer eee 36 3 3 6 Setting the File Name usada eR A TUE E EASE EEEE e 37 23 37 Setting the Cycle Time aede tere EL e ue e eere rione fe ia vester teens 38 3 3 6 Tuning the Magnet rmeter aie i pce Pei e i re e ep e Petre 39 3 3 9 Using the AC Filter ro E aad P e e P e E rire 4I 5 3 LO Setting the Display Mode and e teh Sua Ree need ere esee tb ub rr snestes 42 DD ED DIMUS 46 5 3 12 Changing the Magnetometer ID Number eee esee esee tenerent rennen 46 5 4 WORKING WITH MOBILE MODE ALL MODELS esee ener tenete trennen trennen 47 5 4 1 Performing a Reading uite te er te ee beet tenti rb erbe tori teneo aee E et teres NESS 47 5 4 2 Repeating Reading e s dtd e ere tet e st Ren cet Dee Men iia de eere 50 3 4 3 Monitoring the Noise id ERAS AE UP FEDERER EHE 50 5 4 4 Using the End of Line EOL Function eese eee enne ene neen trennen nennen 51 3 4 5 Evaluating Signal Quality 3 52 agesan onte Ee eq UE eU ERG pert 54 5 5 WORKING WI
41. 7 NOTES The message please wait for pps may not be visible with some GPS boards i e AIISTAR with WAAS Instead you will notice that there may be a because the magnetometer will wait for a minimum of 3 satellites before synchronizing time The time to achieve GPS lock may vary due to sky visibility weather conditions and it is also affected by the satellite parameters stored in the GPS module during the previous surveys Turning off the GPS in Canada and back on in Europe increases the time to lock since new satellites must be tracked The PPS signal is generated when enough satellites are in view to produce a good GPS solution The GPS initialize command has been added to the GPS menu only for convenience Before starting or re starting a survey with the GPS enabled the GPS module is automatically initialized The survey does not proceed until achieving lock condition Normally there is no need to manually initialize the GPS D2 SYNCHRONIZING GPS TIME Select C synch to UTC to manually synchronize the internal timer to UTC Universal Time Coordinate or GMT Greenwich Meridian Time After detecting PPS the unit shows SCREEN D5 Synchronizing to UTC Coordinated Universal Time Now the internal clock is synchronized to GPS UTC time NOTE The synchronize to UTC command has been added to the GPS menu only for convenience Before starting or re starting a survey with the GPS enabled the unit automatically syn
42. A for the decimal point and D as backspace for corrections SCREEN D10 0629229 UTM Easting start point 4857218 UTM Northing start point 00000 x local grid origin 00000 y local grid origin F ok C change GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 111 GSM19 Series Magnetometers Version 7 SCREEN D11 0629629 UTM Easting end point 4857618 UTM Northing end point F ok C change SCREEN D12 00000 line 100 line spacing F ok C change The line number would have to be set to the same value of the Y coordinate of the origin in order to conform to your grid origin setting This number will default even if you change it You must choose an appropriate line spacing and enter it After the last value is entered the unit returns to the GPS menu To proceed with the survey press F The unit returns to the main menu Set the survey mode cycling rate and the other survey parameters in the usual way NOTE that the options for the positioning system are not the same as the previous Line and Station or XY Options that were added in v7 0 include UTM Latitude Longitude e Local Grid e Rotated Grid The data is stored with UTC time as the time stamp and the position in the units of the selected system GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 112 GSM19 Series Magnetometers Version 7 D 4 2 Programmable Waypoints
43. AGNETOMETER IMPORTANT esee eese esee enses tn statu seta tuse ta sns ta sens en sees suse tatu n eun 88 12 CHARGING THE BATTERY IMPORTANT eeeeeee esee ee enean tosta tuse ta sins tn sens enses suse ta sene ta sesso sees sus en sena 88 13 MAINTAINING YOUR SYSTEM IMPORTANT eeeeeee eene eee enata ense ta sns tn stata sesso seta sone ta sesto sees sosta sese 89 14 EVAIERNIMMIUOnv 89 APPENDIX A GLOBAL MAGNETIC MAPS eere esee entes tata ains tn tns tn stata sins totns ons entusiasta snae n sensns ta sn senses ta sn ao 90 A 1 UNDERSTANDING THE DIFFERENT SENSOR ORIENTATIONS eene nennen 90 ALL Overha s r Sensor uen ba E RERO Ger I In 90 A L2 Standard Proton Sensors a ore rer Ie eee e Eri Peer e IRIS Tue rer Eee uds 90 APPENDIX B RAW DATA FILES TRANSMITTED BY RS 232 C eeeeeeeee eee eeee esses tne ta senten statu sess su seta suu 93 Bil MOBILE MODE tevin ait Sl tae Ae Belin Ree ate a Ave eee 93 B 2 BASE MODE ence He aes eme oomen niae Meshes eas 93 Bid VEE OPTION 8 e Steet Sieve Rais Gos Sted ais eae e Randa A ee enu 94 B 4 WALKING MAG OPTION nciht Dt EG P OR EU t eg E RE tertii gone 95 BS GRADIOMETER OPTION eer fioi tede estt to ec e ite mdi en esu etd i tee nd ETET 96 APPENDIX C VLF SURVEY OPTION eere esent tn tna ne natuss natns tn stata enn 97 CT ACCESSING THE VEE FUNCTIONALITY irritare re eire
44. EN 39 lower 99 e lower indicates this is the noise level of the lower channel The noise level is useful for example to evaluate the effect of nearby power lines on a survey The level is internally set to 100 and any value over this indicates a high noise level If high noise levels are encountered you may want to adjust the survey grid location or perform the survey while anticipating that some individual readings may be noisier than desired e Alternatively gradiometer units that are equipped with two channels may display upper if the upper channel is the active one or both upper and lower when in gradiometer mode In any case if there is no external electromagnetic disturbance the number displayed is 100 or less To return to reading mode press F twice 5 4 4 Using the End of Line EOL Function From the Reading Menu press A menu The following screen is displayed SCREEN 40 A position B enter text 4 graph vertical scale C tune 5 display mode E EOL F OK 0 noise info press E EOL EOL is a very useful feature One button E is all that is required to continue a survey with minimum user intervention GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 52 GSM19 Series Magnetometers Version 7 The way the EOL operates depends on the positioning system in use a EOL with Line Station system e Line Coordinate The Line Number is incremented by the current Line Incremen
45. ESCRIPTION eere eene ener tata sna tasses tasas tata sine dsd ek to ta saneta tasse VESE CDEN sensns totns ene sa snae n sta 17 4 STANDARD SYSTEM COMPONEN S iiti iter e EG eR ERR EL Eee be RED Depp Rr trs 17 4 2 NSSEMBLING THE INSTRUMSNENCE ifo ote ire eee p Gos ient de es 19 4 2 1 General Assembly Instructions itte itt ee gta aede ie ehe He See eee bea Ub 20 42 2 Using the Charger ie oed tu dete tereti ee Me teer eri e UE eie e tech 20 4 2 3 Using the 6 Pin Connector cse sa tere stie HR e eel Coe ea Eee tags PEERS on ee eati 21 4 3 DESCRIPTION OF CONNECTORS rrt t ir tti ree rr e ta ree i beer Ep e cheng seed 22 4 3 1 Pinout of a 6 Pin Female Connector eese eese eene tnnt enne ne enne teen enne trennen nne tnen nenne 23 4 3 2 Pinout of a 4 Pin Female ConnectTo iira ee enne nennen nennen rennen rennen enne enne 23 4 3 3 Pinout on BNC Female Connector Fast or Walking modes seen 23 43 4 External Trigger ODtOns i e eater meg tied endi Pede CURE Ce eee eg 24 5 OPERATING INSTRUCTIONS cccsssssssssserssssrsersessrsessessrsessessrsessesensenscsessessesensessessssessesensessccessessesensessesenseseeses 25 S T KEYBOARD DESCRIPTION 2 reci tete e ase o Qa ER eere e Pee Me e uno denis ce SE Ete cipes 25 Di Leh POW OH OM 25 Jd Power Off aad e n per diee dere restet ari ee 25 52 MAIN MEN SS 25 DS SURVEY MENU 5 5 i e ir tek e ose ne Eie Dt gie ea ete eei utes
46. F ok C change C change toggles between yes and no GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 41 GSM19 Series Magnetometers Version 7 e auto tune yes allows the unit to follow changes in the magnetic field with jumps of a maximum of 2 5 uT per reading in the survey area e auto tune no permanently holds tuning at the initial value If tune initialize was set to YES the tuning value obtained during the automatic scan is set for the survey If tune initialize is set to NO the unit retains the tuning value displayed on the next screen To store your selection press F ok If you selected tune initialize no at screen 22 the following screen is displayed SCREEN 24 27 tuning 19 131 microT F ok C change number Enter the first two digits of expected magnetic field first 3 if above 100 kgamma for initial tuning 5 3 9 Using the AC Filter In the Survey Menu press F to highlight AC filter SCREEN 25 survey mode position time file cycle time tuning AC filter display mode text ID 60Hz A start C change lt iam C change toggles between 60Hz 50Hz and No If you select No the reading is defined as the longest measurement possible however the other two settings are recommended because of possible AC interference GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 42 GSM19 Series Magnetometers Version 7 NOTE
47. GSM 19 v7 0 Instruction Manual Manual Release 7 4 March 2008 Our World iSiMagneuc GEM Systems I nc Advanced Magnetometers 135 Spy Court Phone 1 905 752 2202 Markham ON Fax 1 905 752 2205 Canada L3R 5H6 Email info gemsys ca Web http www gemsys ca TABLE OF CONTENTS 1 INTRODUCTION AND TUTORIAL Lorenin niini neer a 4 1 1 USING WALKING MODE WITH GPS eite te tbe dinem ie eie drei KERSTEN 6 DT IGettingStarted i5 ehe e RAI e EEUU OE M AEE e AEREA gine e te EE 6 J L2 Setting the Positioning System ce e t er PE IR te be pea E epe E A EEEE on o pou 6 1 1 3 Changing Time Filename and Cycling esses eene teen nenne ener en rennen ene amp 1 1 4 Setting the Tuning AC Filter and Display Mode esse eese eene enne nennen 8 1 1 5 Working with the GPS Functionality eese eerte nennen eene ener etre enne 9 1 1 6 Starting a Reading Surveying and Stopping Recording eee 11 1 1 7 Dumping Data to a Personal Computer esee eene trennen eene eene ener nennen 12 1 1 8 Considerations for Using RS 232 Waypoint Uploading eese 12 2 THEORETICAL DESCRIPTION cscssssserssssrserssssrsessessrsessessrsesscssrsensessnsessssersessesensesensesscsensesscssesensessesensesseses 15 3 EARTH S MAGNETIC FIELD eee eee esee tnter neta tn suntin tasa tata sinet tasa tata EEEE ta senes EEEE EEEE sensa 16 4 INSTRUMENT D
48. M C Lat Long 6 Then press Next The system transfers the data and displays a message when transfer is complete ka Way Points Transfer Utility File Help Checksum 2095 verified Data succesfully transfered r Coord units GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 15 GSM19 Series Magnetometers Version 7 2 THEORETICAL DESCRIPTION The magnetic field measuring process consists of the following steps a b c d e Polarization A strong RF current is passed through the sensor creating polarization of a proton rich fluid in the sensor In the case of the GSM 19 fast sampling family polarization can be concurrent with other intervals of measurement Keeping the RF on all the time increases the maximum data sampling rate to 5 Hz Deflection A short pulse deflects the proton magnetization into the plane of precession Pause The pause allows the electrical transients to die off leaving a slowly decaying proton precession signal above the noise level Counting The proton precession frequency is measured and converted into magnetic field units Storage The results are stored in memory together with date time and coordinates of measurement In base station mode only the time and total field are stored Overhauser Magnetometer GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 16 GSM19 Series
49. NSOR ORIENTATIONS A 1 1 Overhauser Sensor In equatorial regions the magnetic field direction should be considered horizontal and pointing north to south Here the GSM 19 Overhauser sensor axis must be oriented horizontally in an east west direction In regions north of the 45 line or south of the 45 line the sensor may be oriented in any horizontal direction NOTE Omnidirectional sensors are available for carefree operation Please ask your GEM representative for more information A 1 2 Standard Proton Sensor GSM 19T standard proton magnetometer sensor is constructed differently It has an orientation line engraved at its side In polar regions this line must be vertical and in equatorial regions it is to be horizontal Alternatively the orientation line can be kept vertical and the sensor in principally North South orientation for the whole Earth GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca GSM19 Series Magnetometers Version 7 008 1u Aysueju e10 piel ure 0 S00c u20d3 lapon oneube i puoM wf sn Magnetic Field Intensity Figure A1 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 92 GSM19 Series Magnetometers Version 7 180 150 120 ce 8 LO CO _ O vo A
50. S 400400 LocaLGrip NE CORIGINX 0 0 565 ROTATED GRID 4857618 400 4857547 323 471 329 LOCAL GRID 100 565 ROTATED GRID INTERMEDIATE POINT 200 200 LOCAL GRID 0 283 ROTATED GRID 4857418 200 SECOND LINE AFTER EOL WITH LINE SPACING 100 4857218 e LOCAL GRID X AXIS 4857147 71 EASTING 629229 0629629 0629700 ROTATED GRID X AXIS Ni Figure D 1 Automatic Grid UTM Local Grid and Rotated Grid GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 110 GSM19 Series Magnetometers Version 7 Using the Rotated Grid allows you to have an arbitrary origin that you define and the coordinates always in reference to axes parallel to the grid In short your grid determines the map and not the NS direction The Local Grid is a scaled down local version of the UTM system and it is based on your own arbitrary origin It allows you to use smaller numbers or at least relevant to your origin or your grid To set the automatic grid first define the width of the lane SCREEN D9 lane width 05m F ok C change The available lane widths are 2 5 10 20 25 50 units Press C change to toggle between these values and F ok to accept To define the grid enter all the parameters sequentially as they are requested using F ok to accept or C change to change the digit keys 0 to 9 for the numbers
51. SNSR receives the proton precession signal LWR Lower sensor channel that SNSR receives the proton precession 2 LWR HEZ Om signal Lower polarization Sends RF signal polarizes the lower sensor RS 232 Communication port and input for power GSM 19GW WALKING GRAD GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 23 GSM19 Series Magnetometers Version 7 4 3 1 Pinout of a 6 Pin Female Connector A external trigger B RS 232 C to mag C RS 232 C from mag D of 12V lead acid battery charger E Ground common F external battery 11V to 15V NOTES External power applied to pin F does not charge the internal battery Voltage in excess of 15 volts in pin F may trigger an internal protection and blow the internal fuse Fuses cannot be reset and must be replaced 4 3 2 Pinout of a 4 Pin Female Connector A signal input B Ground C not used D not used 4 3 3 Pinout on BNC Female Connector Fast or Walking modes Center pin RF output Body Ground GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 24 GSM19 Series Magnetometers Version 7 4 3 4 External Trigger Options Those survey modes that require your intervention to take a reading such as Mobile slow Gradiometer or slow modes combined with VLF could also be triggered by external control pulses sent to the 6 pin
52. South Africa 11 DJAKA Djakarta Indonesia 12 EGYPT Old Egyptian 13 ED50 European 1950 14 ED79 European 1979 15 GUNSG G Segara Kalimantan Indonesia 16 GEO49 Geodetic Datum 1949 New Zealand 17 GRB36 Do not use See 76 18 GUAM Guam 1963 19 HAWAII Do not use See 77 or 81 20 KAUAI Do not use See 78 or 82 21 MAUI Do not use See 79 or 83 22 OAHU Do not use See 80 or 84 23 HERAT Herat North Afghanistan 24 HJORS Hjorsey 1955 Iceland 25 HONGK Hong Kong 1963 26 HUTZU See 68 27 INDIA Do not use See 69 or 70 28 IRE65 Do not use See 71 29 KERTA Kertau 1948 West Malaysia amp Singapore 30 KANDA Kandawala Sri Lanka 31 LIBER Liberia 1964 32 LUZON Do not use See 72 33 MINDA See 73 34 MERCH Merchich Morocco 35 NAHR See 74 36 NAD83 N American 1983 Includes Areas 37 42 37 CANADA N American Canada 1927 38 ALASKA N American Alaska 1927 39 NAD27 N American Conus 1927 40 CARIBB See 75 41 MEXICO N American Mexico 42 CAMER N American Central America 43 MINNA Nigeria Minna 44 OMAN Oman 45 PUERTO Puerto Rica and Virgin Islands 46 QORNO Qornoq South Greenland 47 ROME Rome 1940 Sardinia Island 48 CHUA South American Chua Astro Paraguay 49 SAM56 South American Provisional 1956 50 SAM69 South American 1969 51 CAMPO S American Campo Inchauspe Argentina 52 SACOR South American Corrego Alegre Brazil 53 YACAR South American Yacare Uruguay 54 TANAN Tananar
53. TH GRADIOMETER MODE 19G amp 19GW essssseseeseeeeeeneneeeee nennen nennen nene 55 SSL Performing a Reading eee iate re etie tecti ebrii rid erbe tede tee aer teet rhe ie 55 5 5 2 Specifying Gradiometer Sensor Spacing eese eere ener nenne ener 56 5 5 3 Selecting the Display Mode s ioa ERREUR RE QUE ES OE ERI ERE 57 5 5 4 Selecting Magnetometer Channels eee eese esee eee ener nennen nennen nnne 58 5 6 WORKING WITH WALKING MODES 19W 19WG amp 19GFW ssseseeseeeeeeneenee eee nennen nenne 59 3 6 1 Performing a Redding e d eere e pene e Pd radi I er t prega eerta e ete edes 60 5 7 WORKING WITH BASE STATION MODE ALL MODELS eee nre 62 5 7 1 Performing a Reading e pe ee d Heu URDqeseeenaiee e e 62 5 7 2 Stopping Base Station Reading acere tt tov ee Re e ER tete EEE a a 64 5 8 SYNCHRONIZING ROVER AND BASE STATION UNITS ALL MODELS eee 64 5 6 1 Setting the Time on the First Magnetometer eese eene neen enne 64 5 6 2 Transferring the Time eee ua itte m e RED Reb e ON bee IR Ee ERE a aa E aiaia a 65 23 9 APPLYING DIURNAL CORRECTIONS s dirette e idee deg 66 3 9 1 Mag to Mag Diurnal Correction a s itus onies ii ai eE ia eiia E a ra s T 67 5 9 2 File to File Diurnal Correction GEMLinkW Utility eese eene eere nennen 69 6 DATA ORGANIZATION AND TRANSFER e eeeeeeee eese ente
54. able 3 It will appear in small letters Once desired Datum set its necessary to verify acceptance of datum by checking of E test screen 9 If datum typed properly and accepted then desired datum would appear in capital letters on seventh line of screen 9 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 135 GSM19 Series Magnetometers Version 7 8 List of reference documents In case there are some GPS related technical insight questions please refer to NovAtel originated set of documents It includes technical specification options available e t c 1 OEMV family user manual OM 20000093 HW Rev2 pdf 2 OEMV family firmware reference manual OM 20000094 pdf 3 Quick Start guide GM 14915062 pdf 4 Quick reference guide GM 14915061 pdf GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 136 GSM19 Series Magnetometers Version 7 APPENDIX E GSM 19 V7 didD MAGNETOMETER dIdD is a vector magnetometer offering a completely integrated design for continuous monitoring of the Inclination and Declination and total field intensity of the Earth s magnetic field This system employs a mutually orthogonal coil setup that through a simple measurement methodology offers superior stability in comparison with fluxgate magnetometer instruments used for similar applications Please refer to the dIdD Instruction Manual This is separately supplied wi
55. an increment of 1 the left half of the graph becomes the right half and new data is plotted on the left side You is displaying half of the data already viewed on the right side of the screen With an increment of 2 the last point at the left of the graph becomes the first point at the right and a full new screen is plotted To recall data in text mode start from Screen 75 above Toggle to graph mode and then set the increment using the screen below SCREEN 80 incr F ok C change Press C change to set the increment and F ok when ready On survey modes other than base you are prompted to select the value to graph Depending on the mode the options may be e uncorrected field normally lower channel e corrected field data available only after Mag to Mag diurnal correction e grad for grad or walkgrad modes GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 80 GSM19 Series Magnetometers Version 7 SCREEN 81 uncorrected field F ok C change C change toggles between the options When you are finished making your selection press F The following screen is displayed SCREEN 82 000100N 000575E uncorrected field 00100N 0000125E A B C The upper right corner shows the coordinates of the right most readings The bottom left corner shows the coordinates of the left most readings A scrolls the graph backward B scrolls the graph forward C displays the following
56. and screen will show toggling of baud rates on the screen Once communication link works GPS will be switched to 115200 baud rate and it will be ready to be initialized After GPS was powered up it normally takes 10 12seconds before GPS will respond Overhauser Magnetometer GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 125 GSM19 Series Magnetometers Version 7 GEM Systems Overhauser Magnetometer 3 GPS Menu Screen 1 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 126 GSM19 Series Magnetometers Version 7 4 Initialization of GPS Once GPS menu is on the screen then press A Initialize GEM Systems Overhauser Magnetometer Screen 2 Sub menu that consist of four modes of operation and software reset command will come up on the screen A Auto C CDGPS F SBAS O OmniSTAR refer to screen 2 Depending on selection made by operator GPS will either select most appropriate mode of operation automatically operate as CDGPS SBAS or as OmniSTAR receiver Experience shows that normally when A Auto selected GPS turns to SBAS mode of operation over CDGPS even L band signal available As a result precision of position solution is less then possible in Canada Reception of differential corrections from OmniStar requires subscription GEM Systems 19 Overhauser 3 GSM Magnetometer In case user
57. ange p 01 02 03 04 05 A start NOTES 144 GSM19 Series Magnetometers Version 7 Stop yymmdd hh mm 020504 23 00 000000 00 00 000000 00 00 000000 00 00 000000 00 00 E new mode The schedules used in the previous programmed surveys is displayed If the last survey the unit was used in daily base mode the hours and minutes of the first program is those of the daily program but the dates is the last ones stored in memory Press C change to enter different schedules Start p yymmdd hh mm 010 020503 07 00 02 000000 00 00 000000 00 00 000000 00 00 000000 00 00 03 04 05 Stop yymmdd hh mm 020504 23 00 000000 00 00 000000 00 00 000000 00 00 000000 00 00 A move D delete BF E C change A solid black square indicates the first program B scrolls through the programs backward F scrolls forward D delete deletes the program marked with the black square and moves the programs below it up one step in the list A move places a copy of the marked program at the current program number and moves marked program on step down NOTE that this overwrites program number 30 the GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 145 GSM19 Series Magnetometers Version 7 C change deletes the marked program and allows the input of a new one Illegal entries for date and time is rejected and the process must be re started
58. base unit NOTE To perform diurnal corrections the time of the mobile and the base MUST also be synchronized See Time Synchronization in section 5 8 5 3 8 Tuning the Magnetometer In the Survey Menu press F to highlight tuning SCREEN 21 survey mode position time file cycle time AC filter display mode text ID initialize N auto tune Y056 A start C change GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 40 GSM19 Series Magnetometers Version 7 C change lets you change all three parameters as follows 1 Tuning initialize 2 Auto tune 3 Tuning number in uT If you press C change you see the following SCREEN 22 tune initialize yes F ok C change C change toggles between yes and no e If you select tune initialize yes the unit automatically scans through its range for the initial tuning setting This scan is performed only once and before a reading is taken when entering the survey mode from this screen Once tuning is initialized the value of the tuning parameter depends on the auto tune setting NOTE The automatic scanning process may fail in noisy or high magnetic gradient areas In these cases you may use manual tuning by setting tune initialize to NO e If you select tune initialize no you must manually set the field range in screen 24 To store your selection and access the next tuning parameter press F ok SCREEN 23 auto tune yes
59. ceiving 524288 bytes Later more messages is added to this screen as a progress report but the process is automatic and once started it does not require user s intervention GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 87 GSM19 Series Magnetometers Version 7 SCREEN 91 software upgrade in progress please do not touch keyboard 524288 bytes received 07183A4A SCREEN 92 software upgrade in progress please do not touch keyboard 524288 bytes received 07183A4A erasing flash SCREEN 93 software upgrade in progress please do not touch keyboard 524288 bytes received 07183A4A flash erased verified SCREEN 94 software upgrade in progress please do not touch keyboard 524288 bytes received 07183A4A flash erased verified reprogramming flash SCREEN 95 524288 bytes received 07183A4A flash erased verified flash reprogrammed press 1C to reboot Press 1C to reboot with the new software and go to the main menu GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 88 GSM19 Series Magnetometers Version 7 11 STORING YOUR MAGNETOMETER IMPORTANT The unit goes to shelf off mode automatically after 24 hours of being turned off OF command To minimize power consumption from the battery when the unit is not in service the shelf off function switches OFF the main power and also powers down the internal oscillator that normally mainta
60. chnical information visit www gemsys ca 85 GSM19 Series Magnetometers Version 7 9 TESTING YOUR SYSTEM The test function checks various parameters Definitions and actions are as follows e A memory is a test of the RAM Afterward press F to return to the test menu e B keys lets you test each key on the keyboard Afterward press 1C to return to main menu e C display tests all dots on the LCD by drawing different patterns Press F to advance and inspect the drawing to detect LCD problems Afterward the unit returns to the test menu e D rom is a test of the ROM i e where the firmware resides During this test the checksum of the existing data in the ROM is compared to the checksum stored in EPROM e F buzzer sounds the internal buzzer intermittently provided it is enabled Press F to return to test menu 9 1 STARTING THE TESTING PROCESS ROM EXAMPLE From the Main Menu press D test The system displays the following screen SCREEN 88 A memory B keys C display D rom E ext trigger F buzzer v7 0 9 IV 2002 Press D rom The system performs the test and displays a screen similar to the following SCREEN 89 00B8C6E1 00B8C6EI The numbers on both sides of the equal sign should be the same The number on the left side is the checksum stored in the EPROM and the number on the right side is the calculated checksum The checksum shown here is just an example Each unit has its own checksum number GEM Syste
61. chronizes to UTC The survey does not proceed until achieving lock condition and synchronizing the time With GPS enabled the internal timer is always overwritten It is not possible to run a GPS survey with other than UTC GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 107 GSM19 Series Magnetometers Version 7 Normally there is no need to manually synchronize the time unless you need to transfer UTC to other units D3 DISPLAYING CURRENT GPS INFORMATION Select D test to display current GPS information as described below SCREEN D6 094 00007 24 04 02 21 37 38 UTC 122 0629231 4857210 0000174 00008 00008 00008 00000 0001 0002 0000031 0000152 5 FFFFFSCA FIFFFFFE 0 0096 043 8566413 0 793920040 08 NOTE If post processing was enabled in the GPS menu the unit begins storing DGPS binary data when entering this test menu Line 1 094 represents the length of the GPS data in bytes It is obtained by comparing the PPS and internal TCXO A value of 7 is normal Line 2 Displays date and time in UTC Line 3 0629231 4857210 0000174 represent UTM Easting Northing and altitude in meters Line 4 00008 00008 are the position coordinates in the Local Grid Line 5 00008 00000 are the position coordinates in the Rotated Grid 0001 0002 are the current starting and ending waypoints Line 6 0000031 are intermediate calculation numbers and 0000152 is the distance in meters along the cur
62. ckets by managing the cycling time and the station increment If you have too many readings and small station increments some interpolated stations have repeated values B 5 GRADIOMETER OPTION Data obtained with the gradiometer option is sent as follows corrected time line station fieldnT grad nT m field nT 111403 0 00600N 0000100E 57241 40 001 24 057228 30 111421 0 00600N 0000125E 57241 37 001 27 057228 28 Column 1 Time as hhmmss s Column 2 Line number and direction Column 3 Station number and direction Column 4 Unreduced magnetic field Column 5 Magnetic field gradient nT m and sign Column 6 Reduced magnetic field nT GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 97 GSM19 Series Magnetometers Version 7 APPENDIX C VLF SURVEY OPTION The VLF option to the GSM 19 Series is available on its own or in conjunction any model of magnetometer or gradiometer When installed in conjunction with magnetometer modes the VLF mode can be used alone or combined with mag modes GENERAL NOTES Base Station modes cannot be combined with VLF When combined with walk modes the VLF reading is not taken while walking Instead when F is pressed to mark a station label the unit interrupts the cycling take the VLF reading and then prompts you to reassume the magnetometer cycle The walkVLF option is yet to be implemented in version 6 mags OPERATION NOTE The following i
63. cm although two or more sections are sometimes used for maximum sensitivity 4 2 ASSEMBLING THE INSTRUMENT The GSM 19 is very simple to assemble The following picture shows the sensors in Gradiometer or Walkgrad configuration mounted on a back pack Figure 4 Gradiometer and Backpack Assembly GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 20 GSM19 Series Magnetometers Version 7 4 2 1 General Assembly Instructions When assembling the instrument start by 1 Installing the sensor on top of the 4 section of the staff far from any metallic or magnetic object 2 Plug the sensor cable s into the side of the console 3 Check the magnetometer power Typically power is supplied via a 12 volt built in rechargeable battery 4 If you are using an external power supply 250mA or 3W of power connect it to pins E and F of the 6 pin connector at the bottom end of the console Pins B and C are used for RS 232C communications Pin A is reserved for external trigger A spliced 6 pin to RS 232C and external battery cable is optionally supplied with the instrument Pin D is reserved for charging the internal battery 5 If you are using fast sensors optional make sure that there are two short cables sub cables with 2 BNC connectors Connect first the extension cables and then connect both cables to the GSM 19 console BNC and 4 pin connector The lower set of connectors on t
64. connector Auto cycling modes such as Base Walk Mag or Walk Grad do not respond to external trigger commands External trigger can be accomplished in three different ways 1 Using external relay or switch between pins A E e Keep A E open for most of the time e Shorting A E for 10ms 50ms is recognized as a trigger 2 Using external voltage on pin A with E as ground e Keep A at 5V to 12V most of the time e Voltage falling to OV for 10ms 50ms is recognized as a trigger 3 Using RS 232 to GSM 19 at pin B and pin E as signal GND e A Carriage return byte is recognized as a trigger command NOTE Real Time Transmission must be enabled for this trigger mode to operate properly For those external trigger modes involving pin A as an input you can check the status of pin A from the unit s screen From main menu press D test and then E ext trigger The screen shows Pin A floating for the high level conditions and Pin A GNDed for the ground GND level NOTE Pin A is actually never floating It is tied to 5v by internal pull up resistors GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 25 GSM19 Series Magnetometers Version 7 5 OPERATING INSTRUCTIONS This section is intended to give you a basic overview of the keyboard menus and processes required to set up and operate the magnetometer in the field 5 1 KEYBOARD DESCRIPTION The keyboard consists of 16 alphanumer
65. d to be refilled 1 coaxial sensor cable per channel typically RG 58 U and 206 cm long Up to 100m long cable is available optionally Over 20m we recommend a triaxial cable Belden 9222 Fast reading magnetometers have two sensor cables one for RF polarization and a microphone cable for the signal Console with all electronic circuits It has 16 key keyboard graphic display 64 x 240 pixel or 8 x 30 characters sensor and power input output connectors The keyboard also serves as an ON OFF switch 6 pin console connector for RS 232 external power battery charging or external trigger Optional dual analog output is available on a 3 pin connector Sealed connectors i e keyboard and front panel mounting screws are sealed so that the instrument can operate under rainy conditions Charger with 2 levels of charging full and trickle that switch automatically from one to another Input is 110 250V 50 60 Hz All metal console housing for excellent electromagnetic interference EMI protection GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 19 GSM19 Series Magnetometers Version 7 e Aluminum staff with 4 strong tubing sections plastic staff optional This construction allows for a selection of sensor elevations above ground during surveys For best precision the full staff length should be used Recommended sensor separation in gradiometer mode is one staff section 56
66. diurnal corrections and other functions With this version there is a limitation in terms of transferring waypoints to magnetometers i e the system does not support a second decimal place centimetre positions GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 13 GSM19 Series Magnetometers Version 7 The solution for this issue is to copy the executable file GEMLinkW exe directly from the CD to the folder that contains the installed GEMLinkW software This file is typically stored in C Program Files GEMLinkW 3 0 To load waypoints 1 Create an ASCII file with two columns of Easting and Northing data only UTM format supported that includes 2 decimal places but NO decimal point The following shows such a file The last two digits are centimetres If your original file is in metres for example you will have to add two zeros at the end of each number to transfer the file correctly 62891912 485690556 62898934 485692178 62899600 485689000 62892700 485687200 Note When creating files for waypoints transfer it is important to make sure that there are no empty headers or strings characters at the beginning or end of the file or extra spaces at the end of strings within the file 2 Set the communication parameters on the console C info RS 232 menu and then on the magnetometer They must be exactly the same for the upload to work Note that you may have to set your Personal C
67. e Total field from the lower sensor or the Gradient SCREEN 49 graph field display mode F ok C change C change toggles between field and grad Press F ok to select one The following screen is displayed SCREEN 50 graph field no text display mode F ok C change GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 58 GSM19 Series Magnetometers Version 7 Use C change to select the text labels you want to add to the graph The options are e no text e field nT e coordinates e field nT and coordinates e grad nT m e grad nT m and coordinates 5 5 4 Selecting Magnetometer Channels Normally when a GSM 19G gradiometer is used in a single channel mode i e for magnetic readings only the lower sensor is used to take the readings but it is also possible to use the upper channel for this purpose To change the channel access the Main Menu and press C info The following screen is displayed SCREEN 51 F time B RS232 JD dir C review 1 erase file A remote 0 datum E channel 2 buzzer 3 info Press E channel The following screen is displayed SCREEN 52 F ok C change C change toggles between lower and upper channel Press F ok to store your selection GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 59 GSM19 Series Magnetometers Version 7 NOTE This is NOT a permanent selection Even whe
68. e addition of a VLF sensor for combined magnetometer gradiometer VLF measurement is available F 1 MAGNETIC FIELD MEASUREMENT PROCESS The magnetic field measuring process consist of the following steps e Polarization A strong DC opposed to the RF polarization used on Overhauser enhanced units current is passed through the sensor creating polarization of a proton rich fluid in the sensor e Pause The pause allows the electrical transient to die off leaving a slowly decaying proton precession signal above the noise level e Counting The proton precession frequency is measured and converted into magnetic field units e Storage The result are stored in memory together with date time and coordinates of measurements In base station mode only the time and total field are stored Both series GSM 19 and GSM 19T are used and operated in the same fashion The main difference between these models is the addition of an electron rich fluid in the sensor and additional circuits to achieve the Overhauser affect in the GSM 19 system See Appendix A of this User s Manual for proton sensor orientation requirements GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 138 GSM19 Series Magnetometers Version 7 APPENDIX H GSM 19 MAG GRAD SPECIFICATIONS Resolution Accuracy Range Gradient Tolerance Operating Interval Input Output Power Requirements Power Source Battery Charg
69. e is similar to what is has been described in this section A new parameter sensors is shown in the survey menu and it is used to set the distance between the sensors For details refer to section 5 5 2 on Setting the Gradiometer Sensor Spacing 5 7 WORKING WITH BASE STATION MODE ALL MODELS The base station mode is a standard mode in all GSM 19 units This section provides general information about accessing the base station functionality You should also be aware of the unique programmable base station option that was added in Version 6 This capability enables scheduling in three ways Details are provided in Appendix I 5 7 1 Performing a Reading From the Main Menu press A survey to access the Survey Menu and then with survey mode highlighted press C change The following screen is displayed SCREEN 61 A mobile B base C grad D walkmag E walkgrad GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 63 GSM19 Series Magnetometers Version 7 NOTE Your modes may differ depending on your model its software and its hardware Press B to select Base Station The unit returns to Survey Menu The following screen is displayed SCREEN 62 Sua SNP datum time file cycle time tuning AC filter display mode text ID connect sensor now 089123 readings left base A start C change lt lt MUWM gt Press F to highlight datum and then C change to change its value The foll
70. easuring time e Y represents the area under signal amplitude coincident with the time of measurement e 9 means optimal conditions e means unacceptable reading e x 0 causes y 0 but not vice versa GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 55 GSM19 Series Magnetometers Version 7 5 5 WORKING WITH GRADIOMETER MODE 19G amp 19GW The gradiometer option is available in GSM 19G and GSM 19WG Walking Gradiometer units and therefore this section refers only to these units Both units enable you to measure the magnetic field gradient between two sensors These systems measure and store the gradient between the sensors in nT m as well as the magnetic field reading in nT obtained by the lower sensor The difference is that the Walking Gradiometer records data continuously for linear interpolation and referencing of ground positions following the survey 5 5 1 Performing a Reading After the initial start up procedures refer to section 5 3 select the Survey mode from the Survey Menu as follows SCREEN 44 dua position time file cycle time tuning AC filter display mode text ID connect sensor now 029876 readings left mobile A start C change Press C change The following screen is displayed SCREEN 45 A mobile B base C grad GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 56 GSM19 Series Magnetometers
71. eat the process until the frequency for all the stations have been entered GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 99 GSM19 Series Magnetometers Version 7 The next table shows the VLF stations available in the GSM 19 portable transmitter B6 Criggeonn UK 9 Lualualei Hawaii NPM 234 60 jy Jn x gp The US NAVY shuts down its VLF station for maintenance purposes according to the following schedule Please note that this schedule is provided as complementary information and GEM Systems has no control over any changes that may have been implemented US NAVY VLF STATIONS MAINTENANCE SCHEDULE 2300 TO 0900 UT FIRST THURSDAY FRIDAY OF MONTH 2300 TO 0700 UT ALL OTHER THURSDAY FRIDAY 1200 TO 2000 UT TESTING 2000 TO 2200 EACH MONDAY IF HOLIDAY FALLS ON MONDAY TESTING WILL BE PERFORMED ON PRECEDING FRIDAY NSS 21 4KHz 1200 TO 2000 UT TESTING 2000 TO 2200 UT EACH TUESDAY NWC 22 3KHz 0000 TO 0800 UT EACH MONDAY NPM 23 4KHz 1800 TO 0400 UT LAST WEDNESDAY THURSDAY OF MONTH 1800 TO 0200 UT ALL OTHER WEDNESDAY THURSDAY NLK 24 8KHz 1600 TO 2400 UT EACH THURSDAY DURING DAYLIGHT SAVING TIME 1500 TO 2300 UT EACH THURSDAY Once the frequency for all the stations has been entered the selected values are displayed GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 100 GSM19 Series Magnetometers
72. eb Site at www gemsys on ca from the support pages The latest version of GEMLinkW is 3 0 It includes more and better tools than the previous versions A summary of the latest upgrades can be found at www gemsys ca Quantum Technology GEMLinkW 20Updates 20Profile 20Plotting htm GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 70 GSM19 Series Magnetometers Version 7 6 DATA ORGANIZATION AND TRANSFER A new file is created automatically in the following cases 1 You select a new survey mode and take at least one reading 2 The current file runs into a new day midnight crossing 3 You stop and re start a base unit 6 1 FILES AND DIRECTORIES You can store up to 50 files in the mag File names have a format similar to Ol survey m where you can only change the 6 letters between the first number and the period The unit automatically assigns Numbers 01 to 50 and the file extension File extensions include the following m mobile b base g gradiometer fmh fast mag hip chain fma fast mag auto cycle fgh fast grad hip chain fga fast grad auto cycle vX Vif only X represents the number of VLF stations used 1 to 3 mvX mobile vif X represents the number of VLF stations used 1 to 3 gv X gradiometer vlf X represents the number of VLF stations used 1 to 3 wm walkmag wg walkgrad wmv walkmag vlf wgv walkgrad vlf The GSM 19 has a directory function you can
73. en is providing the following information e Up Upper channel if installed e Lo Lower channel e 2840zc of zero crossings taken used for measurement calculation e 1200ms Signal measurement time in milliseconds e 2600 amp 1600 First and last signal measurement amplitudes S N GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 54 GSM19 Series Magnetometers Version 7 5 4 5 Evaluating Signal Quality Each mode which includes the magnetic field measurement has a signal quality indicator that is displayed in text It is stored in memory and it can be recovered using the SEND or File Review functions It is a number presented in the form xy where x and y are between 0 and 9 e X is associated with measurement time and is a sort of gradient indicator e 9 means max measurement time was accomplished e means measurement was too short ee ee ee gt Is 100 200 300 400 500 600 700 800 900 gt 900ms ms ms ms ms ms ms ms ms ms 0 5s 50ms 100 150 200 250 300 350 400 450 gt 450ms Bie E E a E ee den 0 2s lt 35ms lt 40ms lt 60ms lt 75ms lt 90ms lt 115 lt 130 lt 145 lt 158 gt 158ms ie i a a E E E a Table 2 Definition of X The numbers in the table represent the measurement time The value of X is obtained differently depending on the cycling rate and the accomplished m
74. eparator YYMMDDhhmm prog 30 CRLF For example if you are using SPACE as field separator and want to automatically start the base on May 20 2002 at 11 30 AM and stop it on May 25 2002 at midnight you should enter the line as 0205201130 0205252359 file is 1 min short or 0205201130 0205260000 After creating the text file on the PC just follow the step by step instructions provided by GEMLinkW s Programmable Base utility GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 147 GSM19 Series Magnetometers Version 7 APPENDIX J VERSION 7 0 ADDITIONS Version 7 changes provide additional data values including line information for compatibility with Geosoft Encom and other similar earth science software packages and output flexibility This section should be read in combination with Section 6 2 2 which describes data transfer J1 DATA VALUES New data values available for the first time include line numbers preceding data blocks elevation satellites number of picket x and picket y Following is a definition of each new value e Line numbers standard numbers ex line 100 that can be added to the front of data records This enables both easier direct import into software packages and easier manual manipulation of files as it is easier to detect where different blocks of data start and end e Elevation elevation height above sea level values derived from GPS e Satellite
75. er Operating Ranges Storage Temperature Display Dimensions VLF Frequency Range Parameters Measured Resolution Number of Stations Storage Terrain Slope Range Sensor Dimensions Sensor Weight 0 01nT gamma magnetic field and gradient 0 1nT over operating range 15 000 to 120 000nT Over 10 000nT m 3 seconds minimum faster optional Readings initiated from keyboard external trigger or carriage return via RS 232C 6 pin weatherproof connector RS 232C and optional analog output 12V 200mA peak during polarization 30mA standby 300mA peak in gradiometer mode Internal 12V 2 6Ah sealed lead acid battery standard others optional An External 12V power source can also be used Input 110 VAC 60Hz Optional 110 220 VAC 50 60Hz Output dual level charging Temperature 40 C to 50 C Battery Voltage 10 0V minimum to 15V maximum Humidity up to 9046 relative non condensing 50 C to 50 C LCD 240 X 64 pixels OR 8 X 30 characters Built in heater for operation below 20 C Console 223 x 69 x 240mm Sensor Staff 4 x 450mm sections Sensor 170 x 71mm dia Weight console 2 1kg Staff 0 9kg Sensors 1 1kg each 15 30 0 kHz Vertical in phase and out of phase components as percentage of total field 2 relative components of horizontal field Absolute amplitude of total field 0 1 Up to 3 at a time Automatic with time coordinates magnetic field gradien
76. er damage overheating etc The active survey mode and the number of readings that could be taken in that mode until the memory is full are also indicated on the screen NOTE The mobile menu does not have a setting for the DATUM and the base does not have a setting for POSITION 5 3 2 Setting the Positioning System From the Survey Menu scroll with B or F to highlight position SCREEN 7 survey mode SYNUM time file cycle time tuning AC filter display mode text ID 00100N 0000125E A start C change When position is highlighted the unit displays the current position settings To select the positioning system or make changes to the coordinate numbers press C change GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 30 GSM19 Series Magnetometers Version 7 The selection of the positioning system can be made only once per file and only before the first reading of the file is taken Positioning systems cannot be combined Once a reading is taken the current system remains for the rest of the file By default the system used in the last file is the active one If you need to change it do so now before taking any readings The Selection for X Y coordinates looks like SCREEN 8 select positioning system XY each 9999999 to 9999999 or 9999999 99 to 9999999 99 F ok C change or for the Line Station grid system SCREEN 9 select positioning system LINE 0
77. er pH ode teret pst etu ed 97 CA2 SEEECTING VEE STATIONS iiir tr petite rere S cetade eremo e e ne eed 98 C3 STARTING A READING rtr t t o e P Leese seeds chavs vet ee ERE A Ie eerte ADU 101 C4 SIGN CONVENTIONS FOR IN PHASE IP AND OUT OF PHASE OP eeeeeeenenenenen 103 APPENDIX D GPS GLOBAL POSITIONING SYSTEM OPTION eese estne tn tne tne tn tn sna tn aine tn tasas tan 104 DAE SETTING UP THE GPS Dep ae ee 104 D2 SYNCHRONIZING GPS TIME 2 545 etie et E ee eb e RE VE UE oe ee reete o e ih teretes 106 D3 DISPLAYING CURRENT GPS INFORMATION essent nenne nene trennen reete nenne 107 D4 SETTING UP NAVIGATION OBTIONS scien pter cte eraot a ree e UTER beret Te Fee N P ERUS 108 D 4 1 Automatic Grid Setup Line to Line Navigation eese eene nne 108 D 4 2 Programmable Waypoints Point to Point Navigation eese eene rennen 112 D 4 3 RS 232 Waypoint Transfer Point to Point Navigation eese eene nennen 115 D S SURVEYING WITH GPS NAVIGATION eerte tree er Hte e ertet erre berti 117 D 6DGPS POST PROCESSING 5 feci eet ra eir e ete ei Ud eee o eee 121 D 7 CDGPS OMNISTAR GPS OPTION htc ete ett re i RR E NU er e pe ERR ree ERN 124 APPENDIX E GSM 19 V7 DIDD MAGNETOMETER eere ener tn etna nns tn sins tn tasas to tns ta tasas seta sinet tn an 137 APPENDIX F GSM 19T PROTON PRECESSION SYSTEM eee esent entes tata sna tn tassa sine
78. er text field nT the graph along with the magnetic field readout in big digits in upper left display corner is displayed Coordinates line and station or X Y is displayed in small characters in top right corner field nT amp and coordinates both field and coordinates numbers are shown NOTE Gradiometer modes have more options in this screen to accommodate the selection of gradient graph or readouts GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 44 GSM19 Series Magnetometers Version 7 Press F after you have made your selection The following screen is displayed SCREEN 29 yes clear graph F ok C change C toggles between yes and no Once programmed this feature is always active at the start of a survey until you disable it It can only be changed in this screen at the end of the set up menus This feature has no effect on the display when you go from the survey menu back to the survey Yes Always starts the survey with an empty screen The graph starts from the left side and the offset is set to 00 No Displays the last graph from memory and starts adding the new readings at the end of it After you have made your selection press F The following screen is displayed SCREEN 30 Df vertical scale 160nT Use A or B to select the vertical scale and D or C to adjust the vertical offset by one dot of the LCD keep pressed for fast continuous action O
79. ercator e Lat Long Latitude and Longitude i e Easting and Northing e Local Grid Reformatted grid with local coordinates for easier manipulation of survey positions i e you can set your local grid so you do not have to use large numbers such as those generated in UTM coordinates GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 7 GSM19 Series Magnetometers Version 7 e Rotated Grid Grid rotated through a specific angle as defined by the first two waypoints on the starting line If you turn GPS off you only have standard X Y and LINE STATION formats available to you The X Y system uses a Cartesian coordinate system whereas LINE STATION uses line and station numbers that are both annotated with directional information ex N S E W and more Both systems are valid the X Y system may be somewhat easier to deal with as numbers do not require later manipulation LINE STATION positions are annotated as described above and may require that you remove the annotations later in the post processing stage which requires more Work This section describes how to use the Automatic Grid waypoint option with the UTM positioning option 5 Select the position option You have four options available including UTM Lat Long Local Grid and Rotated Grid 6 Select C change The system displays the select positioning system screen Use C change to toggle to the positioning option that you
80. erwise it displays SCREEN G9 050916 waiting for program 07 00 to 19 00 e Where 050916 is the current time in hhmmss e When the start time is reached the survey begins NOTE The start time indicates the beginning of the survey and NOT the time of the first reading Depending on the selected cycling rate the time of the first reading of the file is delayed Furthermore to preserve the battery the GPS module is turned off while waiting for a program start If GPS is enabled the unit turns on GPS and waits for GPS lock and UTC synchronization This imposes a further delay on the time required for the first reading At the stop time the unit stops cycling turns off GPS if enabled closes the current file and waits for the start time the next day The daily survey loop can only be stopped by pressing 1C either while taking readings or while waiting for the start time 1 4 USING THE FLEXIBLE SCHEDULING FEATURE The flexible scheduling feature lets you store up to 30 schedules each with date and time for the start and the date and time to stop the surveys SCREEN G10 base start A immediate B daily C programmable D RS 232 Select C programmable A screen similar to the following is displayed GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca SCREEN G11 SCREEN G12 Start yymmdd hh mm 020503 07 00 000000 00 00 000000 00 00 000000 00 00 000000 00 00 C ch
81. etic field monitoring at Magnetic Observatories volcanological and seismic research etc Figure 1 Sensor and GPS antenna Use a full section staff 56cm between sensor and antenna to avoid magnetic interference GEM System Inc Advanced Magnetometers For more technical information visit www gemsys ca 5 GSM19 Series Magnetometers Version 7 The GSM 19 is a secondary standard for measurement of the Earth s magnetic field with 0 01 nT resolution and 0 2 nT absolute accuracy over its full temperature range Some of the system features include e Microprocessor control with large memory storage capabilities up to 32 Mbytes e Synchronization of and held and base station units with automatic corrections for diurnal variations of magnetic field e Access to results in serial form RS 232 C interface for collection by data acquisition systems terminals or computers e On line Real Time Transmission RTT and post operation transfers e Gradiometer mode with strict control of measuring intervals and concurrent measurement of two magnetic fields The result is a high quality reading independent of diurnal variations of magnetic field e Option VLF sensor for combined magnetometer gradiometer VLF measurement The GSM 19 Series of magnetometers includes several models each with different features and options In addition each mode and option can be used in different ways resulting in a variety of combinations The purpose
82. etometers Version 7 deviations in values such as would be encountered in a moving survey N N For use with a base station i e where the unit is stationary and not affected by large survey related jumps in the magnetic field AC Filtering controls whether 50 Hz or 60 Hz filters are added for suppression of noise from powerlines The final value discussed in this section is the Display Mode which is used to control the appearance of the data onscreen while the survey is being performed 16 Move the cursor to the tuning menu item and select C change The system displays the tune initialize screen Set the value to yes by pressing the C change button 17 Then press F ok to exit The system displays the autotune screen Set the value to yes by pressing the C change button The system returns to the Survey menu 18 Move the cursor to the AC filter item and select C change The system changes between three values no 50 Hz and 60 Hz Select the one that you want to use 19 Move the cursor to the display mode item and select C change The system shows the display mode screen and the current setting either text or graph If you e Select text and F ok the system automatically returns you to the Survey menu after your selection e Select graph and F ok the system adds a second value field nT This means that the field value will also be displayed You can use the C change button to select from other labeling opt
83. etometers Version 7 0 9 digits can be entered A dp places decimal point after that only 2 more digits are allowed B toggles sign D backsp backspace Erases last digit or decimal point entered E enter press if number is correct If you selected Line Station positioning system two screens are displayed one for the Line and the other for the Station settings SCREEN 12 LINE 00100 N F OK change A number B coordinates EOL INCREMENT 00100 change C sign D number LINE INCREMENT 00000 change E sign 0 number changes line number changes line cardinals N NE E SE S SW W NW changes EOL increment sign changes EOL increment u J a W 2 changes line increment sign changes line increment NOTE The EOL increment only affects the Line number see section 5 4 4 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 33 GSM19 Series Magnetometers Version 7 SCREEN 13 STATION 012345 50 E change A number B coordinates STATION INCREMENT 00012 25 change C sign D number F OK changes station number changes station cardinals N NE E SE S SW W NW changes station increment sign o a ww o changes station increment When you press A number D number or 0 number the following screen is displayed SCREEN 14 E enter C clear Here you can enter the required number using 0 9 digits and A as a decimal point Then use C clear to make cor
84. etting the Time In the Survey Menu press F to highlight time SCREEN 16 survey mode position Siima file cycle time tuning AC filter display mode text ID 13 V 96MO15 05 04 0 time running this time has been set by keyboard A start C change The line that has this time has been set by keyboard can also have other values as follows e has been set by GPS e has been set by default e has been set by cable synch e has been set by remote To change the time press C change and the following screen is displayed SCREEN 17 wyymmddhhmmss c clear GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 37 GSM19 Series Magnetometers Version 7 Now enter the date and time In case of a typing error press C e w weekday 1 Monday 7 Sunday e yy year e mm month e dd day e hh hours in 24h system e mm minutes e ss seconds When all of the digits are entered the unit displays the following screen SCREEN 18 F start clock Press F when you intend to start the time NOTE Units equipped with GPS overwrite this time with UTC when GPS is enabled 5 3 6 Setting the File Name In the Survey Menu press F to highlight file SCREEN 19 survey mode position time cycle time tuning AC filter display mode text ID Olsurvey m A start C change B2WE gt GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca
85. f the screen shows the battery voltage SCREEN 2 A survey B diurn cor F GPS C info OF off D test 15 II 00 E time synch 1 send TU 01 04 15 45 erase 2 enter text 13 2V From the Main Menu you can press the following to go to the menus shown on the right Survey Menu see section 5 3 Diurnal correction see section 5 9 Info Menu see section 5 4 5 Test see section 9 coc W SP Time Synchronization see section 5 8 1 Data Transfer see section 6 2 F GPS option see Appendix D 45 Data Erasing see section 8 2 Text Mode see section 5 3 10 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 27 GSM19 Series Magnetometers Version 7 5 3 SURVEY MENU The Survey Menu is the main menu you use for acquiring data To access the Survey Menu make sure you are in the Main Menu and press A The active option on the survey menu is the one highlighted with reverse video Pressing B moves the highlighted marker backward and F moves it forward Once the desired option is highlighted press C change to change its settings SCREEN 3 y position time file cycle time tuning AC filter display mode text ID connect sensor now 029127 readings left mobile A start In the Survey Menu you can press the following to initiate the actions shown on the right F move forward or B move backwards through the parameters C change settings of the highlighted parameter A start the
86. for exchanging sensors or sensor cables the instrument is generally not field serviceable Numerous self test possibilities and warnings make the diagnostics reasonably easy though The sensor should be kept clean and free of ferromagnetic particles dust etc The liquid of the Overhauser sensors is sealed in a pyrex bottle Refilling is neither possible nor needed 14 WARRANTY IMPORTANT ALL GEM Systems magnetometers excluding batteries are guaranteed for replacement of defective parts and correction of defective labor for two years from shipping date Shipping costs are not covered IMPORTANT NOTE Any unauthorized opening of the sensor or console without written consent of GEM Systems Inc will void the warranty GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 90 GSM19 Series Magnetometers Version 7 APPENDIX A GLOBAL MAGNETIC MAPS Official International Geophysical Reference Field IGRF maps of the total magnetic field and its inclination are shown in Figures A1 and A2 Refer to map A1 to estimate the total magnetic field of your survey area On map A2 areas with inclination more than 45 are considered polar areas while those with less than 45 inclination are equatorial areas although some parts of equatorial areas lay far away from geographic equator i e almost all of South America and most of Africa A 1 UNDERSTANDING THE DIFFERENT SE
87. graph setting screen To change the graph s settings press C The following screen is displayed SCREEN 83 D f vertical scale 20 nT GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 81 GSM19 Series Magnetometers Version 7 Here you have the following options A reduces the vertical scale B increases the vertical scale C moves the graph down keep pressed for continuous action D moves the graph up keep pressed for continuous action F returns you to graph review When reviewing base files The upper left corner shows the time hhmmss of the left most reading The upper right corner shows the time of the rightmost reading A scrolls the graph backward B scrolls the graph forward Although base readings are always uncorrected the label uncorrected field may be shown SCREEN 84 123456 125634 uncorrected field Press C to change the graph s settings SCREEN 85 D f vertical scale Here you have the following options GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 82 GSM19 Series Magnetometers Version 7 A reduces the vertical scale B increases the vertical scale C moves the graph down D moves the graph up F returns you to the graph review screen GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 83 GSM19 Series Magnetometers Version 7 8 ERASING MEMORY
88. he unit s display and in this manual is referred to as lower while the upper set is referred to as upper 6 If you are using slow sensors optional make sure that you have one short cable with a BNC connector First connect the extension cable and then connect 4 pin connector to the GSM 19 console Again the lower 4 pin connector on the display is referred to as the lower and upper 4 pin connector is referred to as upper 7 If you are using the VLF unit optional connect the VLF cable plastic connector to VLF sensor and the metal shell connector to the mag 8 If you are using the backpack accessory optional install the sensors in the unit for hands free operation Refer to picture on the previous page for a general overview of the backpack assembly 9 If you are using the GPS sensor optional refer to Figure 1 to see how the unit is configured Make sure that you connect the antenna cable to the BNC connector marked with a yellow tag on the right hand side of the console 4 2 2 Using the Charger The charger supplied with the magnetometer is of wide input voltage range 100 250 VAC 50 60 Hz The fast charging indicator of the battery charger will light when battery charging is in progress and charging should be allowed to proceed until the indicator goes off GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 21 GSM19 Series Magnetometers Version 7 4 2 3 Using the
89. hese processes 7 1 SELECTING A FILE TO REVIEW From the Main Menu press C info The system displays the following screen SCREEN 73 F time B RS232 D dir C file review A remote O datum E channel 2 buzzer 3 info Press C file review SCREEN 74 file F ok C change number Select the file you want to review by pressing C change and entering the file number and press F ok The system displays the following screen SCREEN 75 text display mode F ok C change C change toggles between text and graph GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 77 GSM19 Series Magnetometers Version 7 In either case the next screen after pressing F ok you are prompted to set the review increment SCREEN 76 incr F ok C change The increment is used in different way depending on the mode a in text mode the value represents the number 1 to 999 of readings to jump while scrolling through the data b in graph mode the value is the number 1 to 180 of 1 2 screens 120 dots to increment The next step depends on the survey and display mode you are reviewing e text mode Section 7 2 or e graph mode Section 7 3 7 2 DATA RECALL IN TEXT MODE To recall data in text mode start from Screen 75 above Then set the increment using the screen below SCREEN 77 incr F ok C change GEM Systems Inc Advanced Magnetometers For more technical informatio
90. ical keys The function of the keys is described below 5 1 1 Power On 1 Press the button labeled B on the console to turn the GSM 19 on 2 If during power up you hold the power button B for about 2 seconds the following screen is displayed SCREEN 1 Gem Systems GSM 19GW 9001054 52 West Beaver Creek Road 14 Richmond Hill Ontario L4B 1L9 Canada tel 905 764 8008 fax 764 2949 www gemsys on ca info gemsys on ca bytes v7 0 10 IX 2000 4194304 Screen 1 displays the company address telephone fax e mail and website The bottom line displays the software version date and the total storage capacity of the unit in bytes You can access the same information screen by pressing C info and then 3 info from the main menu screen Once the power button is released the unit proceeds to the Main Menu Options and their functions are explained later in section 5 2 5 1 2 Power Off To switch the unit off press the O and F keys simultaneously at any time in any menu 5 2 MAIN MENU To position the magnetometer in the Main Menu press the 1 and C keys simultaneously at any time All of the valid options and their functions are displayed on the screen in the form of a letter digit followed by a dash and then a brief description of its function GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 26 GSM19 Series Magnetometers Version 7 The 13 2V on the bottom right corner o
91. ilter and Display Mode With an advanced magnetometer there will be some sort of tune initialize function that is responsible for finding the precession signal ex similar to a radio station and a second auto tune function that tracks the precession signal as it changes in amplitude With GEM there are 4 possible states of the two controls as follows Tune initialize Autotune Use When Y Y Average magnetic field value at the survey location is not known or alternately as a default for maximizing signal to noise ratios Y N Magnetometer is running automatically ex as a base station and there is some magnetic noise in the vicinity for example from vehicles nearby The magnetometer may lose its signal when these extreme noise events occur however it will recover gracefully as it will use the tune initialize value for readings that follow N X For fastest readings reading time is minimized as the system will not scan over the entire frequency range i e disabled In addition it is recommended for areas with very high gradients the magnetometer may saturate at these points but will recover gracefully once the magnetometer passes by anomalous zones Another possible use is with a base station where the unit is stationary and the base unit does not have to handle large GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 9 GSM19 Series Magn
92. inkW expects SPACE as the default delimiter between fields or columns but a different one can also be selected The magnetometer consoles can store up to 1000 waypoints Therefore the files should have 1000 or less lines or rows However if the file is larger only the first 1000 lines is transferred A CR carriage return or CRLF carriage return Line feed determines the end of each line Lines terminated only with LF cannot be used since they are treated as a single line A general description of the file format follows Easting WPointl Separator Northing WPointl CRLF Easting WPoint2 Separator Northing WPoint2 CRLF Easting WPoint3 Separator Northing WPoint3 CRLF Easting WPoint1000 Separator Northing WPointl000 CRLF NOTE The coordinates of the waypoints may be entered as UTM The following is an example of valid UTM coordinates to program WP1 to WP5 with SPACE as field delimiter between columns WP6 to WP1000 have their UTM coordinates set to zero 629260 4857196 629268 4857195 629271 4857194 629361 4857193 629262 4857192 After creating the text file on the PC open GEMLinkW access the Transfer GPS waypoint utility and just follow the step by step instructions provided GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 117 GSM19 Series Magnetometers Version 7 NOTE It is advised to use GEMLinkW version 2 4 or higher as of this release of the manual the
93. ins time Date and Time have to be programmed again the next time you use the unit NOTE that date and time can only be maintained within 24 hours after the unit is switched off If the unit is stored for very long time in addition to the automatic shelf off function the internal battery should be periodically recharged see below 12 CHARGING THE BATTERY IMPORTANT The internal battery is 12V lead acid 2 0 Ah battery To maximize its lifespan you MUST maintain it in the following manner e Do not allow the battery to fully discharge since this may cause internal leakage or shorts e Even if an external battery is used charge the internal battery frequently e Always keep it charged charger is automatic so overcharging is not possible Additionally the shelf off function is triggered automatically after 24 hours of having the unit switched off by pressing OF e If the unit is used daily always charge it overnight If the unit is left on for a long period of time and the battery voltage drops to 8 5V it automatically switches off 24 hours later the automatic shelf off is triggered NOTE Batteries are NOT included in the normal warranty provided by GEM as their lifespan is determined by the way in which they are normally maintained GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 89 GSM19 Series Magnetometers Version 7 13 MAINTAINING YOUR SYSTEM IMPORTANT Except
94. ion survey programs or schedules that determine the date and time to start and stop the base The schedules can be entered using the keypad or transferred from a file on a PC using GEMLinkW 5 8 SYNCHRONIZING ROVER AND BASE STATION UNITS ALL MODELS If you intend to use two or more GSM 19s for example a Rover unit such as aGSM 19 in mobile gradiometer walking or walking gradiometer mode and a Base Station unit in the survey to later perform diurnal correction you must synchronize their times 5 8 1 Setting the Time on the First Magnetometer First you have to set the right time on one of the mags Refer to 5 3 3 Setting Time and then transfer it to the other units using the synchronization cable and the procedure described below IMPORTANT NOTES Units equipped with built in GPS overwrites the local time with UTC when GPS is active e If ALL units are equipped with GPS they all automatically synchronize to UTC and the GPS timing controls their cycling This is the optimum synchronization and in this case there is no need to transfer the time from one unit to another e lfonly ONE unit is equipped with GPS you should synchronize that unit to UTC see Appendix D and then use the synchronization cable to transfer the UTC time to the other e Also note that in this case the cycling of one unit is synchronized to GPS time every reading taken The other unit runs on its internal timer with no further GPS synchronization Therefore
95. ions such as coordinates field nT amp coordinates or no text When you press F ok again the system displays the clear graph screen For continuous plotting of values leave this value set to no When you press F ok again the system displays the vertical scale screen Use the C and D keys and the A and B keys to change the base line position and the vertical scale of the graph respectively 1 1 5 Working with the GPS Functionality The GPS functionality is accessed with the Main survey screen and specifically the F GPS control Once you have turned the GPS functionality on you will see a GPS screen with the following four values e A initialize Manual initializing of GPS Normally GPS is initialized when you start the survey however if you experience a situation in which the GPS is not responding you may want to try to manually initialize the GPS GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 10 GSM19 Series Magnetometers Version 7 20 21 22 23 24 75 26 Zh 28 e B navigation This is the main access point for the waypoint options Automatic Programmable and RS 232 as well as lane guidance for controlling the width of acceptable deviation i e wander from the grid lines e C synch to UTC Manual synchronization of GPS Normally GPS is synchronized when you start the survey however this functionality is intended for synchronization of no
96. it www gemsys ca 115 GSM19 Series Magnetometers Version 7 SCREEN D16 0629229 UTM Easting waypoint 0001 F ok C change SCREEN D17 0629229 UTM Easting 4857547 UTM Northing waypoint 0001 F ok C change The process is the same for waypoint 2 and the rest When the Northing for the last waypoint you want to program is entered you may press E end to return to the GPS menu D 4 3 RS 232 Waypoint Transfer Point to Point Navigation This is not a navigation mode It is actually a tool to program the waypoints If the survey involves several waypoints programming them one by one using the unit s keypad may become quite a task Instead you may use the RS 232 port to transfer the waypoint from a file on your PC NOTE To transfer the waypoints you MUST have GEMLinkW 2 4 or newer installed on your PC and use the Transfer GPS waypoint utility GEMLinkW is freely available from GEM Systems web site The text files may be created using GEMlinkW in editing mode or with any other word processor capable of saving as plain ASCII text Spreadsheet programs such as Microsoft Excel can also be used provided the files are saved as text space comma TAB or colon separated and not as worksheets or workbooks GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 116 GSM19 Series Magnetometers Version 7 The files must have two columns one for each UTM coordinate of the waypoints GEML
97. ive Observatory 1925 Madagascar 55 TIMBA See 85 56 TOKYO See 86 57 TRIST Tristan Astro 1968 Tristan du Cunha 58 VITI Viti Levu 1916 Fiji Islands 59 WAK60 See 67 60 WGS72 World Geodetic System 1972 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 134 GSM19 Series Magnetometers Version 7 61 WGS84 World Geodetic System 1984 62 ZANDE Zanderidj Surinam 63 USER User defined Datum 64 CSRS Canadian Spatial Ref System epoch 2005 65 ADIM Adindan Ethiopia Mali Senegal Sudan 66 ARSM ARC 1960 67 ENW Wake Eniwetok Marshall Islands 68 HTN Hu Tzu_Shan Taiwan 69 INDB Indian Bangladesh 70 INDI Indian India Nepal 71 IRL Ireland 1965 72 LUZA Luzon Philipines excluding Mindanoa Is 713 LUZB Mindanoa Island 74 NAHC Nahrwan Saudi Arabia 75 NASP N American Caribean 76 OGBM Great Britain 1936 Ordinance Survey 71 OHAA Hawaiian Hawaii 78 OHAB Hawaiian Kauai 79 OHAC Hawaiian Maui 80 OHAD Hawaiian Oahu 81 OHIA Hawaiian Hawaii 82 OHIB Hawaiian Kauai 83 OHIC Hawaiian Maui 84 OHID Hawaiian Oahu 85 TIL Timbalai Brunei and East Malaysia 1948 86 TOYM Tokyo Japan Korea and Okinawa In order to set desired Datum press button D datum from GPS menu GEM Systems Screen 10 Press C change and that type in desired Datum name from list available from T
98. jects away from the sensor In normal applications the magnetometer console does not produce appreciable effects on measurements provided that the sensor is installed on the staff and kept at least at arm s length from the operator and the console GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 17 GSM19 Series Magnetometers Version 7 4 INSTRUMENT DESCRIPTION Before starting you should be aware of some general terminology that applies to GEM s magnetometers and gradiometers ROVER and BASE station modes are terms that describe the operating characteristics of instruments whereas SLOW and FAST reading rates describe the cycling characteristics of instruments Specifically e ROVER mode refers to instruments that physically move throughout the survey GEM delivers instruments that operate in mobile i e magnetometer gradiometer walking magnetometer and walking gradiometer modes e BASE station mode describes stationary units used for diurnal correction e SLOW cycling rates describe instruments that cycle from 3 seconds to 1 hour e FAST reading rates describe instruments that cycle from 0 5 seconds to 1 hour i e include all SLOW reading rates By default all GSM 19 series magnetometers gradiometers have a mobile and base station mode and cycle at a slow reading rate However if you purchase additional options such as walking mode or walking gradiometer rover mode your ins
99. m time file cycle time tuning AC filter display mode text ID connect sensor now 089123 readings left base A start GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 140 GSM19 Series Magnetometers Version 7 1 From the survey menu select cycling rate tuning time and other parameters in the normal way 2 Connect the sensor s and if required the GPS antenna 3 Press A start to proceed NOTE If tune initialize is set to YES it is activated at this point Make sure the sensors are connected to the unit Otherwise tune initialization fails and this affects all the scheduled base surveys Programmable bases can be operated in three different modes e Immediate e Daily e Programmable The screen for the base mode used in the last survey is displayed Press E new mode to change the base mode SCREEN G3 base start A immediate B daily C programmable GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 141 GSM19 Series Magnetometers Version 7 I 2 USING THE IMMEDIATE SCHEDULING FEATURE The Immediate scheduling feature lets you start the base station instantly following the initial setup Select A immediate The following screen is displayed SCREEN G4 base will start immediately A start E new mode The immediate mode is the normal manual base mode Pressing A start starts the survey and you must press 1C to st
100. ms Inc Advanced Magnetometers For more technical information visit www gemsys ca 86 GSM19 Series Magnetometers Version 7 10 UPGRADING INTERNAL SOFTWARE FIRMWARE One of the new features in v7 0 is the ability to upgrade your magnetometer s internal software 1 e firmware from a PC using the 6 pin connector for the RS 232 port and the file transfer cables 10 1 USING THE GEMLINKW UPGRADE UTILITY The Upgrade utility of GEMLinkW provides all the functionality required to upload the new software to the unit and guides you to the process with step by step instructions For your reference the screens below illustrate the messages that the unit displays during the software upgrade process NOTES To avoid hardware software incompatibility the source software files are released as required and normally named as the serial number of the unit with extension bin If you need to upgrade or want to check whether new functionality is available for your system through upgrades please contact GEM Systems at support gemsys on ca and include Upgrade in the title of your message For upgrades we provide a file containing the source code and GEMLinkW or other upgrade package provided by GEM Systems 10 2 ACCESSING THE UPGRADE MODE To access the upgrade mode the unit must be in the test menu When the transmission begins the unit displays the following SCREEN 90 software upgrade in progress please do not touch keyboard re
101. n GPS magnetometers and gradiometers The way you use this is to first synchronize the rover assuming this is the GPS unit and then connect the rover to the base magnetometer and synchronize the times using standard synchronization cables and functionality e D test This is a very useful display menu that shows you what the GPS system is seeing when you have it turned on Parameters include Lat Long UTM number of satellites strength in decibels and other values From the Survey menu press F GPS The system displays the GPS screen Press C change to set the GPS to Yes Press F ok The system displays the Navigation menu You can choose to initialize values or more commonly to set the Navigation options Select B navigation The system displays the lane guidance and grid setup screen You have the option of changing the setting from no to yes as required Generally you want to have lane guidance active so use C change to set the value to yes and then press F ok The system displays the grid setup screen In this example choose the A automatic grid setup option This creates a grid of 500 parallel lines as defined by the starting and ending waypoints of the starting line The system displays the lane width screen Use the C change control to set the lane width i e tolerance value for navigating along the lines to the appropriate value say 25m Press F ok The system displays the start point screen Enter the starting Easti
102. n visit www gemsys ca 78 GSM19 Series Magnetometers Version 7 Press F after your selection The following screen is displayed SCREEN 78 056789 34 000000 0 11 22 33 4 27 IX 96 00100N 0000125E A B C 99 e Online I the value to the left is the uncorrected field and the value to the right is the corrected field e On line 2 time of the reading hh mm ss s e On line 3 date of the reading day month year e On line 4 left Line and Station A displays an older reading current increment B displays a newer reading current increment C displays the change of increment screens 99 represents the signal quality factor Base files are reviewed in a similar way but the corrected field and the position labels are not displayed SCREEN 79 056789 34 27 IX 96 11 22 33 4 B C 99 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 79 GSM19 Series Magnetometers Version 7 NOTE Depending on the survey mode some files like mobile and slow grad are reviewed from the last reading to the first Some others like base and walk modes are reviewed from the first to the last 7 3 DATA RECALL IN GRAPH MODE After selecting graph mode you are prompted to set the increment or the scroll jump to use while reviewing along the graph Allowed increment values are 1 to 180 An increment of 1 represents 120 points of the graph equals half a screen For example with
103. n the upper channel is selected for single channel modes the unit defaults to the lower channel after a grad mode is used 5 6 WORKING WITH WALKING MODES 19W 19WG amp 19GFW GEM s unique Walking Magnetometer Gradiometer enables acquisition of nearly continuous data on survey lines Thanks to the Overhauser effect enhancement exclusive of GEM Systems sampling rates that could otherwise be obtained only with optically pumped systems can be achieved with excellent results Similar to an airborne survey in principle data is recorded at discrete time intervals normally up to 2 and optionally up to 5 readings per second as the instrument travels along the line At each survey picket the operator presses the designated key The Walking Mag records the coordinates of the picket and automatically assigns linearly interpolated coordinates to all intervening readings see section 6 2 3 Near C ontnuous Surveys Improve Definition of Magnetic Anomalies 66000 65000 64000 G SM 19 Walking Mag 63000 Standard Mag 62000 61000 60000 59000 Magnetic Field Intensity nT 58000 57000 56000 50 75 100 125 150 175 200 Position rn Dats Courtezy of VAL D OR GEOPHYSD UELTEE NOTE When a Walking Mag or Grad is used with GPS coordinates the system does not perform interpolation at pickets instead it uses the actual GPS position at each designated time as specified through the survey cycle time
104. ng and Northing of the first waypoint i e for the line you want to use as your starting line After you enter your first two points you will see local grid origin x and y values You can choose to set these to local values so that the eastings and northings map to a local grid you are using In this case we will assume the default values i e 0 and continue After you enter the local grid y value the system displays the end point screen Similarly to the starting point screen complete all values as required and press F ok The system displays the line screen The line screen offers the opportunity to add a unique line number for each line of the survey This will be recorded in the output file along with a line notation a standard GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 11 GSM19 Series Magnetometers Version 7 notation used by software programs such as Encom Geosoft and Intrepid This was a key upgrade in version 7 i e to enable seamless data transfer from GEM output ASCII files to destination programs 29 Select C change and enter a value say 10 for this parameter The system displays the line spacing item You can use this control to define how far apart you would like your lines defined 30 Press F ok The system displays a please wait message while it generates the grid This can take up to a minute to generate so please be patient When finished
105. nly a short rounded indication of the vertical scale appears on the 1 line of the screen The actual values are the ones shown in the following table The vertical units are nT i e full scale from top to bottom of the screen The horizontal range is always 240 dots and each dot represents a reading GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca GSM19 Series Magnetometers Version 7 5 12nT 5nT 655 36nT 650nT 1310 72nT 1300nT 2621 44nT 2600nT 5242 88nT 5000nT Table 1 Vertical Graph Display Ranges GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 46 GSM19 Series Magnetometers Version 7 5 3 11 Entering Text In the Survey Menu press F to highlight Text SCREEN 31 survey mode position time file cycle time tuning AC filter display mode ID A start C change C change allows an entry of a text with comments or observations pertinent to the survey More text or comments can be added later as the survey progresses see section 5 4 1 Each file may have its own text including base mode You can recover the text later using SEND dumping data in a separate file or you can access it chronologically with the data 5 3 12 Changing the Magnetometer ID Number In the Survey Menu press F to highlight ID SCREEN 32 survey mode position time file cycle time tuning AC filter display mode text 123456789 A start
106. nstructions are regarding the VLF option only It is assumed that the operator knows how to operate the GSM 19 magnetometer If not please refer to GSM 19 Manual for more detailed operation description C1 ACCESSING THE VLF FUNCTIONALITY Press B to turn power on and display the Main Menu Press A Survey to access the Survey Menu Press C to change the Survey Mode Depending on the available survey modes a screen similar to the following one is displayed SCREEN Cl A mobile B base D vlf E mobile vlf Press D or E or the command to the VLF survey mode you want to use GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 98 GSM19 Series Magnetometers Version 7 C2 SELECTING VLF STATIONS The VLF unit may be tuned to up to 3 VLF stations simultaneously and store the readings from each during the survey On the next screen enter how many VLF stations you want to use SCREEN C2 of VLF stations Enter 1 2 or 3 The stations used in the last survey if any is displayed SCREEN C3 17 1 19 6 24 0 F ok C change number Press F ok to accept or C change number select different stations To select different stations scrolling with B and F highlight the frequency in kHz from the list of the available VLF stations and press A select station to save your option SCREEN C4 16 0 16 4 17 1 17 4 18 6 19 0 19 6 21 4 22 3 23 4 24 0 24 8 28 5 A select station Rep
107. ntial that your transmission settings are the same on the magnetometer gradiometer as on the Personal Computer You can check and change baud rates etc by selecting C info from the Main screen followed by B RS232 40 Initiate dumping by selecting the 1 Send command from the Main Menu The system displays the file screen 4 Use C change number to change the identifier of the file you want to dump if you need to see which files are in the mag use the C info C file review function first When finished press F ok The system displays the select SEND format screen 42 Select from D default or F Custom Values you can use include X Y time nT nT m corrected nT cor nT signal quality SQ elevation new for version 7 satellites sat picket x and picket y Custom allows you to arrange these in any order you would like default provides a preset listing of values in GEM format 43 When ready to send data press A send The system downloads the data 44 Options A and E give you the choice to select A all or F field values only Select the data you want to send The system automatically displays an ending now 1C stop message when finished 1 1 8 Considerations for Using RS 232 Waypoint Uploading If you want to use the magnetometer s guidance features one way to do so is to load a series of waypoints from a Personal Computer Please note that you installed a demonstration version of GEMLinkW 3 0 software for downloading
108. of this manual is to introduce the most important modes features and options After understanding these it is easier to see how they combine with the others If your system has a feature that is not described here please contact us As well we welcome suggestions about ways in which we can enhance this manual based on your experiences Overhauser Effect An exclusive feature of GEM Systems Magnetometers In contrast to a standard proton magnetometer sensor that uses a proton rich liquid an Overhauser Effect sensor has a free radical added This free radical ensures the presence of free unbound electrons that couple with protons producing a two spin system A strong RF magnetic field is used to disturb the electron proton coupling By saturating free electron resonance lines the polarization of protons in the sensor liquid is greatly increased The Overhauser effect offers a more powerful method of proton polarization than standard DC polarization i e stronger signals are achieved from smaller sensors and with less power GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 6 GSM19 Series Magnetometers Version 7 1 1 USING WALKING MODE WITH GPS Welcome to the v7 0 Tutorial for GEM magnetometers and gradiometers using Walking Mode with GPS This guide provides you with the basic information required to get started You may also want to supplement your review of this tutorial by referring to
109. omputer s communication port to 3 4 or 5 depending on your system s configuration 3 Open GEMLinkW and select the Tools RS 232 Transfer Transfer GPS waypoints PC to console option The system displays the Waypoints Transfer Utility screen fed Way Points Transfer Utility File Help This utility transfers the navigation Way Points from a PC text file to VERSION 6 GSM 13 and GSMP 30 magnetometers equipped with full GPS firmware Please follow the step by step instructions provided in this window Select the Field Delimiter fle menu the Coordinate Units and open the file containing the Way Points Coord units UTM 4 Select the Open file button and then locate your waypoint file Press Ok The system displays a message similar to the following The current active serial port is COMS5 Make sure the RS232 port of the mag is connected to it GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 14 GSM19 Series Magnetometers Version 7 5 Press the Next button and follow the instructions on the screen for setting up the magnetometer to receive waypoints kx Way Points Transfer Utility File Help From the mag s main menu press F GPS Make sure GPS is set to YES Press F ok and then B navigation Make sure Lane quidance rotated grid is set to YES Press F ok and then C RS 232 transfer unit will display please wait Click next when done Coord units UT
110. on the operator is facing is considered positive while decreasing magnetic field is considered negative 1 Ifstation has coordinates N NE E SE and the station increment is positive signs for IP and op are not changed 2 Ifstation has coordinates N NE E SE and station increment is negative signs for IP and op are inverted 3 Ifstation has coordinates S SW W NW and the station increment is positive signs for IP and op are inverted 4 Ifstation has coordinates S SW W NW and the station increment is negative signs for IP and op are not changed GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 104 GSM19 Series Magnetometers Version 7 APPENDIX D GPS GLOBAL POSITIONING SYSTEM OPTION At GEM we address our customer requests for GPS and its higher resolution derivative Differential GPS DGPS through both built in and external GPS options Built in GPS offers many advantages because it minimizes weight and removes bulky components that can be damaged through normal survey procedures IMPORTANT NOTES The GPS antenna must be connected to the BNC connector MARKED WITH YELLOW located on the RIGHT HAND SIDE of the console Do NOT connect the GPS antenna into the BNC connector for the sensor RF on the left hand side The antenna will be damaged beyond repair The GPS antenna MUST be mounted a minimum of one full section staff 56cm apart from the sensors to avoid magnetic interference
111. op it I 3 USING THE DAILY SCHEDULING FEATURE The Daily Base scheduling feature lets you run the base station every day by starting and stopping at designated times SCREEN G5 base start A immediate B daily C programmable D RS 232 Select B daily SCREEN G6 base will run every day from 07 00 to 19 00 A start C change E new mode GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 142 GSM19 Series Magnetometers Version 7 NOTES The start and stop times used in the last survey is displayed If in the last survey the unit was used in the programmable mode the start and stop times displayed is those of the first program in memory Press C change to enter different start and stop times SCREEN G7 base will run every day from to Enter the time as hh mm in 24 hrs format If an invalid number for hours or minutes is entered the unit displays SCREEN G8 base will run every day from 66 00 to 19 00 illegal entry Pressing F returns both times to 00 00 To enter the correct time start the process again When the last digit has been entered the unit returns to screen G6 and displaying the new program Press A start to start the base GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 143 GSM19 Series Magnetometers Version 7 If the start time has already passed the unit starts immediately Oth
112. or 6 will come up depending on how GPS was initialized to work either with OmniSTAR or with CDGPS In case if SBAS mode was selected then attempt to receive L band info will show message on the screen 7 GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 131 GSM19 Series Magnetometers Version 7 GEM Systems Screen 7 This is due to the fact that SBAS it is L1 band based augmentation system and in such configuration L band receiver is disabled In the case if GPS initialized to receive L band signal then screens 4 or 6 will come up for CDGPS or OmniSTAR respectively Lock time parameter will reflect length uninterrupted tracking of satellite signal 5 L 1 satellite info Press 1 to verify status of L1 satellites info GEM Systems Screen 8 On this screen 14 satellites visible and in use will be shown by names numbers along with elevation azimuth and carrier to noise density ratio Satellites which show 00dB being excluded from computation of position Press F to return to GPS menu GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 132 GSM19 Series Magnetometers Version 7 6 E test E Test option of GPS menu allows seeing actual positioning solution provided by GPS regardless of how GPS initialized GEM Systems REI Oe ae Screen 9 First line of screen 9 is empty Second line consists of status S
113. owing screen is displayed SCREEN 63 56000 00 datum F ok C change number The number that appears on the screen is the one that was set by the last user You can change it by pressing C and set the desired number NOTE The Datum represents the offset or shift imposed to the Diurnal Corrected see next section 5 9 It has no influence on the readings or the survey itself It is only used with the SEND command when dumping or transferring files that have been subject to Diurnal Correction Its value is normally the expected magnetic field of the area and it could be set after the survey or before dumping the data Moreover a file could be transferred several times each time with a different datum to obtain different offsets on the corrected data GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 64 GSM19 Series Magnetometers Version 7 After setting display mode cycling rate and the other parameters as it has been explained before for the mobile mode see sections 5 3 3 to 5 3 9 press A start to start the base file 5 7 2 Stopping a Base Station Reading The only way of stopping a Base survey is by pressing 1 C to force the return to main menu If the base is re started a new file is created NOTE Optionally v7 0 GEM Systems magnetometers may be equipped with a Programmable Base Station feature The programmable base allows you to enter and store up to 30 base stat
114. perator will be offered to choose one of eight available geographical areas Screen 5 Those areas are Eastern US Central US Western US North Central and South America Asia and Pacific Islands Africa Europe Africa and Mid East Australia and Far East To scroll forward between areas press B to scroll backward press A to select chosen area press GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 129 GSM19 Series Magnetometers Version 7 Screen 6 First line of screen will show serial number of GPS receiver needed to activate OmniSTAR subscription Second line will show how many hours left till subscription expires This data being received from satellite and in case GPS is not activated then it shows 0000 hours Third line shows name of satellite that oversees selected geographical region and its frequency Forth line shows actual measured frequency of beam received by antenna and carrier to noise density ratio Fifth line is empty and reserved for future use Sixth line shows number of seconds receiver is being locked on carrier Change between carriers within same geographical region or change of geographical zone will reset counter to 0 as well as repeated initialization routine or power down will do the same Seventh line represents Signal Tracking Status 82 stands for phase locked and signal is being tracked For more detailed explanation please refer to Table 1
115. rections or E enter to store When you press B coordinates the following screen is displayed SCREEN 15 enter NESW Use the blue letters on the keyboard to select the desired cardinal point GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 34 GSM19 Series Magnetometers Version 7 NOTES For a standard survey do not use LINE INCREMENT set it to 0 You can use LINE INCREMENT if you are surveying a base line or tie line Otherwise you would be walking diagonally on your grid If you are planning to use station interpolation for walk files see section 6 2 3 keep in mind the number of readings and the distance between pickets by managing the cycling time and the station increment If you have too many readings and small station increments some interpolated stations have repeated values 5 3 3 Understanding the Line Station Positioning System N station station station station 600 00 W 587 50W 587 50E 600 00E If you walk East from station 600 00W If you walk West from station 600 00E you must use 12 50 station you must use 12 50 station increment increment S In both cases when you pass through station 0 00 the GSM 19 automatically changes E to W or W to E and the sign of the station increment The station increment is used in a mathematically correct way and is related to the direction in which you are walking As per the above diagram the same applies to N or S s
116. rent line wpl wp2 direction in this example from current location to the ending waypoint wp2 in this example Line 7 displays the addresses of the memory locations used to store DGPS binary data and the percentage of memory used to that purpose Line 8 043 8566413 079 3920040 are Latitude and Longitude in decimal degrees 08 is the number of satellites in view GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 108 GSM19 Series Magnetometers Version 7 D4 SETTING UP NAVIGATION OPTIONS Select B setup to access the GPS aided navigation menu SCREEN D7 Lane guidance amp grid setup no F ok C change Press C change to enable or disable this option This option enables you to enter up to 1000 waypoints in one of 3 ways automatically from keyboard or from computer and uploading SCREEN D8 A automatic grid setup B programmable waypoints C RS 232 waypoints transfer The characteristics of these navigation modes are explained in the sections that follow D 4 1 Automatic Grid Setup Line to Line Navigation With the A automatic grid setup option you can generate a rectangular grid with parallel lines separated by a specified increment for example 100m You must define the START and END points in UTM only for the first line and the line increment If you enter a positive value for the increment the lines are added in a counter clockwise direction In the diagram
117. s number of satellites visible for GPS or DGPS corrections for each reading This value can give a measure of survey positioning quality e Picket x an X positioning value that is assigned to a specific reading location This value can be used for geo referencing maps to specific pickets or in re establishing positions on the ground for drilling or other follow up e Picket y a Y positioning value that is assigned to a specific reading location This value can be used for geo referencing maps to specific pickets or in re establishing positions on the ground for drilling or other follow up J2 PROGRAMMABLE OUTPUT Now when you use the Send function 1 Send in the Main menu to transfer data from the magnetometer console to a computer you see two options Default and Custom Default values change according to the survey mode ex Base Mobile Grade Walkmag Walkgrad For example if you are working with a Walkgrad with GPS selecting Default sends values in the following order e X UTM Lat Long X Line e Y UTM Lat Long Y Station e Elevation m e MaginnT e Grad in nT m e Signal Quality sq GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 148 GSM19 Series Magnetometers Version 7 e Corrected Mag cor nT e Satellite sat e Time time e Picket x picket x e Picket y picket y Selecting Custom provides you with the option of changing the Defaul
118. se readings is the time stamp of the readings e Ifthe time of the readings of the mobile unit exactly match the time of the readings of the Base unit the Diurnal Correction is performed directly according to the equation above e If the times do not match the magnetic field from the Base unit is obtained by linearly interpolating the field of the two Base readings that are closest in time to the Mobile reading The best way of obtaining diurnal corrected data is by using a Base Station and a Mobile unit GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 67 GSM19 Series Magnetometers Version 7 An alternative method involves using only one unit and a special type of readings called Tie Point Reading The Tie Point method is not as effective since it implies interpolating readings with a large time interval and it is very seldom used It was a standard feature on previous models but has not been implemented in our version 6 magnetometers If you are interested in using Tie Point Corrections with a version 5 or earlier magnetometer please refer to our web site that has a technical note on this subject When using two units the Diurnal Correction can be performed unit to unit by sharing the contents of their memory or File to File after dumping the files to a PC and using GEMLinkW s Diurnal correction Utility 5 9 1 Mag to Mag Diurnal Correction When performing Diurnal Correction by connecting
119. survey After tune initialize if enabled the following screen is displayed SCREEN 55 A stop C walk To start reading press C walk The magnetometer starts cycling at the pre set rate If in graph mode the last graph in the memory may or may not be displayed here depending on how the clear graph setting has been programmed see section 5 3 8 In any case press C walk again to start reading As you walk the lines press F at the designated pickets to insert position labels between the data lines of the file NOTES e Keep the F key pressed for a few seconds to be sure the picket has been marked A black rectangle shows at the bottom of the screen to indicate the command was accepted The beeper sounds briefly if it is enabled e If GPS is enabled this command is not available Each reading is stored with its coordinates GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 62 GSM19 Series Magnetometers Version 7 To stop taking readings press A and hold it until the display is blank When A is released the following screen is displayed SCREEN 56 A position B enter text 4 graph vertical scale C tune 5 display mode E EOL F ok O noise 1 info Please look for the descriptions of these options in section 5 4 1 GSM 19GW units combine the functionality of the GRADIOMETER with the WALKMAG to provide the WALKGRAD mode The operation of the unit in this survey mod
120. survey at any time GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 28 GSM19 Series Magnetometers Version 7 5 3 1 Setting the Survey Mode In the Survey Menu highlight survey mode and press C change The survey modes that are applicable for the unit are displayed NOTE The available survey modes of your unit may differ from the ones shown here depending on its model its software and its hardware SCREEN 4 A mobile B base C grad D walkmag E walkgrad and select A mobile B base station C grad D walkmag E walkgrad After a survey mode has been selected the settings that apply to that mode is displayed For example if the mobile survey mode is selected you see SCREEN 5 Sua SEM position time file cycle time tuning AC filter display mode text ID connect sensor now 029123 readings left mobile A start C change MON gt GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 29 GSM19 Series Magnetometers Version 7 If the base survey mode is selected you see SCREEN 6 Sua SENSE datum time file cycle time tuning AC filter display mode text ID connect sensor now 089123 readings left base A start C change MUS gt CAUTION Before taking a reading check to make sure all cables and sensor s are connected This maximizes the lifespan of your system and protects internal RF circuits from wat
121. t e Station Coordinate The Station Number remains the same but the Station Increment reverses sign With this simple process the operator is ready to walk to the next line of the grid and start taking the readings moving in the opposite direction he or she walked the previous one However if the next line starts at a different station number you may press A or B to change the current station number backward or forward by the pre set station increment SCREEN 41 A B F ok LO00100N S0000225E b EOL with X Y coordinates e XandY coordinates both increment by their respective EOL increment e XandY increments both reverse sign If you need to make further adjustments you may press A or B to change the current X and Y coordinates backward or forward by their respective increments NOTE To walk along X lines set Y increment and X EOL increment both to zero To walk along Y lines set X increment and Y EOL increment both to zero GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 53 GSM19 Series Magnetometers Version 7 5 4 5 Displaying System Information From the Reading Menu press A menu The following screen is displayed SCREEN 42 A position B enter text 4 graph vertical scale C tune 5 display mode E EOL F OK 0 noise info Then press 1 info The following screen is displayed SCREEN 43 up 2840zc 1200ms 2600 1600 lo 2780zc 1200ms 2500 1600 This scre
122. t slope EM field frequency in and out of phase vertical and both horizontal components for each selected station 0 90 entered manually 140 x 150 x 90 mm 5 5 x 6 x 3 inches 1 0 kg 2 2 Ib GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 139 GSM19 Series Magnetometers Version 7 APPENDIX I PROGRAMMABLE BASE OPTION The programmable base feature allows full control over the base surveys It is particularly useful for remote or unattended base stations By programming or scheduling the base you can determine when the surveys begin and end hours days or years in advance This result in a more efficient use of batteries or other available power sources and also avoids storing in memory hours or days worth of unwanted data Because a new file is created every time a base survey starts each schedule has its own file I 1 SETTING UP THE PROGRAMMABLE BASE STATION OPTION From the Main Menu press A survey to access the Survey Menu and then with survey mode highlighted press C change NOTE If GPS synchronization is required make sure the GPS is enabled SCREEN G1 A mobile B base C grad D walkmag E walkgrad NOTE The available survey modes of your unit may differ from the ones shown here depending on its model its software and its hardware Press B to select Base Station The unit returns to Survey Menu with the following screen SCREEN G2 j datu
123. t order to any ordering of values you would like as well of duplication of values if required for any reason GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca
124. tations GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 35 GSM19 Series Magnetometers Version 7 5 3 4 Understanding the X Y Positioning System N T uy x 600 00 x 587 50 x 587 50 x 600 00 If you walk East from x 600 00 If you walk West from x 600 00 or any other point you must use or any other point you must use 12 50 x increment and 0 y increment 12 50 x increment and 0 y increment vey For clarity in the above diagram X axis is aligned EW and y axis NS but they could also represent any other grid The x increment is used in a mathematically correct way and also indicates the direction in which you are walking Similar rules apply for walking in y direction e Walking north or east requires a positive increment regardless of where you stand e Walking south or west requires a negative increment The x increment must be zero if you walk along y lines NOTE All the numbers shown above are just examples the range of numbers which can be used are GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 36 GSM19 Series Magnetometers Version 7 Line 0 to 99999 Station 0 to 9999999 or 0 00 to 99999 99 Xy 9999999 to 49999999 or 9999999 99 to 9999999 99 The same limits apply for the increments but selections must be done in such a way that after the increments are added the numbers are still within range 5 3 5 S
125. th the dIdD system GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 137 GSM19 Series Magnetometers Version 7 APPENDIX F GSM 19T PROTON PRECESSION SYSTEM The GSM 19T is a portable standard without Overhauser enhancement proton magnetometer gradiometer designed for hand held or base station use for geophysical geotechnical or archaeological exploration long term magnetic field monitoring at Magnetic Observatories volcanological and seismic research etc The GSM 19T is a secondary for measurement of the Earth s magnetic field having 0 2nT resolution and InT absolute accuracy over its full temperature range The GSM 19T is a microprocessor based instruments with storing capabilities Large memory storage is available up to 2Mbytes for version 5 and up to 32Mbytes for version 6 units Synchronized operation between hand held and base station units is possible and the corrections for diurnal variations of magnetic field are done automatically The results of measurements are made available in serial form RS 232 C interface for collection by data acquisition systems terminals or computers Both on line and post operation transfer are possible The measurement of two magnetic fields for determination of gradient is done concurrently with strict control of measuring intervals The result is a high quality gradient reading independent of diurnal variations of magnetic field Optionally th
126. the last used cycle time is restored in each of the survey modes GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 39 GSM19 Series Magnetometers Version 7 The definition of cycle time is different for different survey modes e In mobile gradiometer mobile vlf or gradiometer vlf modes the GSM 19 does not cycle automatically You must press a button to take each reading The cycle time in these modes represents the maximum waiting time to match the seconds and fraction of seconds to those of a base station unit cycling at the same rate This ensures that there is a reading on the base station taken precisely at the same time and that interpolation of the base unit readings is not required during diurnal corrections see section 5 9 When the unit is set to immediate start lines 6 amp 7 of the LCD show immediate start correction with interpolation This means that once in survey mode pressing any button starts a reading immediately Because there is no waiting time the time stamps of the readings of the mobile unit may not match the time stamps of the readings of the base station During diurnal correction the base readings are linearly interpolated to the time of the mobile unit e Base walk fast and marine modes are auto cycling modes The cycle time is the time between consecutive readings For more precise diurnal correction press D or C to select the same cycle rate as the
127. the rest of the manual 1 1 1 Getting Started Gettting started is easy simply requiring turning on the magnetometer and then accessing the main Survey menu 1 Start by turning the mag on B power button You are in the Main menu 2 Select A Survey You are now in the Survey menu 3 Press C Change to set the survey mode You may see for example that A mobile discontinuous survey B base and C walk nearly continuous survey modes are available to you 4 Select the survey mode option C walk This resets the file number as well Note that re setting the survey mode is the only way to create a new file You must do this after each survey so that you can continue with following lines or survey blocks i e depending on the way you run your surveys 1 1 2 Setting the Positioning System GEM s GPS functionality is based on waypoints and includes three waypoint options e Automatic Grid Setup Specify the endpoints for the start and end of the first survey line and the system automatically creates 500 survey lines parallel to the defined line e Programmable Waypoints Define waypoints on the keyboard This can be challenging to do except for the shortest of files Generally not recommended e RS 232 Waypoints Transfer Define a waypoint file on your PC and upload it using the RS 232 capabilities on the magnetometer gradiometer You can use this functionality with one of four positioning options e UTM Universal Transverse M
128. tn tasas tata sensn 138 F 1 MAGNETIC FIELD MEASUREMENT PROCESS eese eene tene teen trennen reete serei eses 138 APPENDIX H GSM 19 MAG GRAD SPECIFICATIONS eere esee eee ee tna n senta anta n etnia sine ta tasas tetas enean an 139 APPENDIX I PROGRAMMABLE BASE OPTION eeeeeeee eene eene teste tata satiata sine to tasas estas en stata senate tn etas 140 L1 SETTING UP THE PROGRAMMABLE BASE STATION OPTION eene eene 140 L2 USING THE IMMEDIATE SCHEDULING FEATURE eese enne nennen trennen rennen 142 L3 USING THE DAILY SCHEDULING FEATURE steer enne tnne tene tree tren tren reete entente 142 L4 USING THE FLEXIBLE SCHEDULING FEATURE eese eerte nenne tren teen reete O E SEE 144 L5 TRANSFERRING SCHEDULES FROM YOUR PC TO YOUR GSM 109 ssssssesseeeeeneen ene 147 APPENDIX J VERSION 7 0 ADDITIONS eese estne te testet tata satiata sins ta tasas tetas sistit sist tasas sata sine sa tasas tan 148 JI DATA VALUES E X 148 J2 PROGRAMMABLE OUTPUT 5 e net aee cette etes levet A a e Eats eere a EC et de cete de Deva evo 148 4 GSM19 Series Magnetometers Version 7 1 INTRODUCTION AND TUTORIAL The GSM 19 is a portable high sensitivity Overhauser effect magnetometer gradiometer designed for hand held towed or base station use Applications include geophysical geotechnical or archaeological exploration long term magn
129. trument is automatically upgraded to a fast cycling rate Please keep this terminology in mind when reading the next two sections and other parts of the manual that describe the various operating modes and options 4 1 STANDARD SYSTEM COMPONENTS The following images show the standard components that are shipped with a GSM 19 system Figure 2 GSM 19 Case with Sectional Staff rods Assemble these rods if you are planning to conduct a Mobile survey i e one with discrete stations as opposed to a walking or continuous survey GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 8 GSM19 Series Magnetometers Version 7 Figure 3 Standard magnetometer components include a sensor console radio frequency cable download cable shoulder harness sensor mounting rod and RS 232 cable Also included here are a GPS and GPS support rod For a complete list of parts consult your packing slip It may show for example that you have an additional sensor and radio frequency cable i e for a gradiometer configuration The following list summarizes the STANDARD parts that are shipped with a GSM 19 system 1 sensor for magnetometer and 2 for gradiometer Sensors are dual coils designed to reduce noise and improve gradient tolerance Coils are electrostatically shielded and contain a special proton rich liquid in a sealed Pyrex bottle Radio Frequency RF resonator The liquid does not nee
130. ttn tns tn tuse ta son suse ta sens tn sesta sees sosta sene ta sesta sone tn ao 70 6 LFILES AND DIRECTORIES eera nendeni eeii o e e rt er p e ec ee de et qe 70 6 2DATA TRANSEER 5 d beide or p eue api e e HE D e ra te ae 71 6 2 1 Setting the RS 232 format a ei e ee eet e rp Mn rede Le eI rne HE eO 71 6 2 2 Transferrine the Datz s eiie ete Stt e a fete o de aate co de dea eee eue da 73 7 RECALLING 76 T L SELECTING A FILE TO REVIEW nie htt bss ons Er EE ete i Re OR be geared day cteass 76 1 2 DATARECALL IN TEXT MODB trente eese t RE e Gade oeil rice eens 77 73 DATA RECALL IN GRAPH MODE 25 rt ti ar tene sec ees e de he LP Ue ce eee o inen 79 EMUCNPnn 83 8 1 STARTING THE ERASING PROCESS arnein esseer E e rennen nete nennen tnn then teet nenne sten enne ESEESE retener eee 83 9 TESTING YOUR SYSTEM A 85 9 1 STARTING THE TESTING PROCESS ROM EXAMPLE esses eene eene enne ettet enne treten nennen nennen eere nnn 85 10 UPGRADING INTERNAL SOFTWARE FIRMWARE eeeeen sees enne tn einsehen ense ia tuse tatnen stata sees suse ta snot 86 10 1 USING THE GEMLINKW UPGRADE UTILITY isr enoa ar nennen nenne tree trennen nennen 86 10 2 ACCESSING THE UPGRADE MODE nirien ireren ee e oo eE EEEE SPO eO EEE nennen ener enne KES nenne tree trennen teen nenne 86 11 STORING YOUR M
131. two units the Base readings are transferred to the Mobile file and stored in it This permanently modifies the original Mobile file and memory NOTE Because the flash memory chips cannot be overwritten DO NOT perform a second diurnal correction on a file that has been already corrected or the file may be corrupted After a Mobile file has been merged with a Base file the corrected data is available for file review either in text or graph mode see section VII or data transfer see section 6 2 2 The actual correction is not performed during the transfer but while dumping or reviewing a Mobile file that has been merged with the base readings This allows you to perform many corrections or files review all with different values of Datum if needed To change the Datum before dumping or reviewing the file press C info from the Main menu and then 0 datum NOTE You require a reduction cable 6 pin to 6 pin cable to connect the two units NOTE The same cable is used for time synchronization This is why sometimes it is called Reduction Cable and sometimes Synch cable Please contact GEM Systems if you need to order one GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 68 GSM19 Series Magnetometers Version 7 IF YOU HAVE VERSION 6 AND VERSION 5 UNITS 1 Turn both units on 2 Connect reduction cable 3 Make sure the base unit is in its main menu 4 From main menu press B diurn cor
132. use to show all the files in the mag e To access this function press C info in the Main Menu and then press D dir The file names are displayed on the left and the number of readings in this file on the right e Press F quickly to view the next files e If you press and hold F you see the file number followed by the date and the time of the first reading of the file GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 71 GSM19 Series Magnetometers Version 7 6 2 DATA TRANSFER Data transfer is enabled via RS 232 downloading from the magnetometer to computer This section describes how to access this functionality and set download parameters such as baud rates 6 2 1 Setting the RS 232 format Before transferring data you have to set the RS 232 format Once set the RS 232 format is saved in the memory From the Main Menu press C info SCREEN 65 F time B RS232 D dir C review A remote O datum E channel 2 buzzer 3 info Press B RS 232 to access the RS 232 setting for the SEND data dump function SCREEN 66 RS 232 115200 bps send 8 data bits 1 stop bit no parity F ok C change e Press F ok if selection is correct e Press C change if you need to change the transfer rate GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 72 GSM19 Series Magnetometers Version 7 SCREEN 67 50 110 300 600 1200 24000 48000 9600
133. vey 35 When you arrive at waypoint 1 use the B control to increment the waypoint to waypoint 2 Then press F start survey The system synchronizes to UTC time Note This can take up to fifteen minutes when you are first using the magnetometer in a new part of the world Please be patient If there is no action within this period you can try to re initialize using the re initialize function as described in the Working with GPS Functionality section of this tutorial 36 On proper initialization the system displays the stop walk screen after you press F start survey Select C walk The system displays the line picket display screen GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 12 GSM19 Series Magnetometers Version 7 Note The system is actively recording measurements actively at this time so you must be walking 37 When finished your line press A This stops data acquisition 38 Now use the navigation functionality to move from waypoint 2 to waypoint 3 When you have arrived at waypoint 3 use the B control to increment the waypoint to waypoint 4 which is your next destination Press F start survey and continue taking measurements as described here 39 When finished all lines press 1 and C keys at the same time The system returns you to the main menu and closes your file so that it is protected 1 1 7 Dumping Data to a Personal Computer When dumping data it is esse
134. wait while scanning through its range for the initial tuning value e Iftextis selected in Display Mode see section 5 3 9 the following screen is displayed SCREEN 34 A menu 1 repeat same position other keys read L 100 N S 200E To take a reading press any other key with the exception of A which returns you to the menu GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 48 GSM19 Series Magnetometers Version 7 e If you need to repeat a reading press 1 This repeats the reading for the current Line and Station or X Y without position increments see section 5 4 2 NOTE Readings are stored in memory as they are taken with no further user intervention After the reading is performed the following screen is displayed SCREEN 35 56 789 34 nT 12 34 nT A menu 1 repeat same position other keys read L 100 N S 200 E where the e first number 56 789 34 is Total Magnetic field in nT e second 12 34 is the difference with the previous reading also in nT e third 99 is the signal quality see 5 4 8 e last line is displaying line and station numbers or X Y coordinates If graph is selected in Display Mode the screen corresponds to your choice of e graph only no text e graph and field nT e graph field and coordinates e see 5 3 9 Setting the Display Mode GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys
135. www gemsys ca 102 GSM19 Series Magnetometers Version 7 To access the Scan option from the Reading Menu press A menu SCREEN C8 A position B enter text 3 vlf C tune D delete E EOL f OK O noise info Press 3 vlf and then C scan on the following screen SCREEN C9 B slope C scan D enter vlf stations F ok Other options are B to manually enter a terrain slope to be stored with vlf data C to scan all VLF stations and display field strength for each D to change frequencies of VLF stations F exits to survey mode GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 103 GSM19 Series Magnetometers Version 7 The VLF Survey Mode also has a correction for the tilt level of the VLF sensor for up to 10 from the horizontal plane When the VLF sensor is tilted more than 10 the computation process stops and the following message appears on the display until the tile is corrected SCREEN C10 24 0 kHz Tilt 14 15 V A menu l repeat same position L00100N 500112 50 E 14 deviation of the sensor from the vertical in the X direction in degrees 15 deviation in the Y direction lt gt A V show the direction the sensor should be rotated to correct the tilt C4 SIGN CONVENTIONS FOR IN PHASE IP AND OUT OF PHASE OP Measured components are vertical in and out of phase relative to the total horizontal field Rising magnetic field in the directi
136. xt point TO AUTOMATICALLY CHANGE NAVIGATION START WP1 END WP2 TO START WP2 END WP3 4857618 4857547 DISTANCE TO WAYPOINT 5 bn LANE WIDTH 4857418 4857218 WP 3 4857147 EASTING 0629229 0629300 0629429 0629629 0629700 Figure D 2 Waypoint Navigation New Navigation Feature In August September of 2002 the navigation display was enhanced through the addition of a large directional arrow on the face of the LCD unit This feature is designed to assist you in staying precisely on track during your survey To see how this new feature looks and works turn on your unit and access the navigation option GEM Systems Inc Advanced Magnetometers For more technical information visit www gemsys ca 114 GSM19 Series Magnetometers Version 7 The first step to program the waypoints is defining the width of the lane SCREEN D13 lane width 05m F ok C change The available lane widths are 2 5 10 20 25 50 meters Press C change to toggle between these values and F ok to accept To define the grid enter all the parameters sequentially as they are requested using F ok to accept or C change to change the digit keys 0 to 9 for the numbers A for the decimal point and D as backspace for corrections SCREEN D14 00001 start waypoint SCREEN D15 00001 start waypoint 00002 end waypoint GEM Systems Inc Advanced Magnetometers For more technical information vis

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