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PowerMAX Receiver

1. Currently we recommend using only the AOR E satellite prn 120 and the IOR W satellite prn 126 Refer to Appendix D Resources for information on how to monitor the status of the ESTB Note The satellite elevation angle lowers with increasing distance away from the equator and from the satellite s longitude Although a good amount of signal coverage is shown in Northern latitudes for both W AAS and EGNOS it may not be usable due to its low elevation angle and the potential for it to be obstructed Ideally testing of the system in the area of its use is recommended to ensure that the signal is sufficiently available Note The SBAS signal coverage may be present in some areas without either sufficient ionospheric map coverage or satellites with valid orbit and clock correctors In such a case differential positioning with SBAS may not be desirable or possible as four or greater satellites with correctors must be available to compute a DGPS position The next section provides further information on the ionospheric map features of SBAS and the PowerMAX receiver Figure C 1 W AAS Coverage PowerMAX User Manual 52 csi wireless Figure C 2 EGNOS Coverage SBAS lonospheric Map Extrapolation To improve upon the ionospheric map provided by SBAS the PowerMAX receiver extrapolates a larger ionospheric map from the broadcast coverage map extending Its effective coverage This allows the P
2. PowerMA A Reference Manual Part Number 875 0112 000 D ate April 2004 e fe So csi wireless Copyright Notice Copyright 2004 CSI W ireless Inc All rights reserved No part of this manual may be stored ina retrieval system transmitted or reproduced by any means including but not limited to photocopy photograph digitizing or otherwise without the prior written permission from CSI W ireless Inc Trademarks The CSI W ireless logo COAST and e Dif are trademarks of CSI W ireless Inc All other trademarks are the property of their respective owners FCC Notice This device complies with Part 15 of the FCC Rules O peration is subject to the following two conditions 1 this device may not cause harmful interference and 2 this device must accept any interference received including interference that may cause undesired operation CSI Wireless Inc 4110 9 Street SE Calgary Alberta Canada T2G 3C4 Telephone number 1 403 259 3311 Fax number 1 403 259 8866 E mail address info Q csi wireless com W eb Site www csi wireless com PowerMAX User Manual ji e fe Ve csi wireless CSI Wireless Limited W arranty CSI W ireless Inc CSI hereby warrants solely to the end purchaser of the Products subject to the exclusions and procedures set forth herein below that the Products sold to such end purchaser shall be free under normal use and maintenance from defects in material and
3. manually forced to 2D or 3D A automatic sw ap between 2D and 3D Position mode 1 fix not available 2 2D fix 3 3D fix Satellites used in the position solution a null field occurs if a channel is unused Position Dilution of Precision PDO P 1 0 to 9 9 Horizontal Dilution of Precision H DO P 1 0 to 9 9 Vertical Dilution of Precision VDO P 1 0 to 99 Checksum Carriage return and line feed 24 csi wireless 5 2 4 GST Data Message The GST message contains Global N avigation Satellite System GN SS psuedorange error statistics The table below breaks down the GST message into its components This message has the following format G PG ST hhmmss ss a a b b c c d d e e f f q g cc lt C R gt lt LF gt Table 5 6 GST Data Message Defined Field Description hhmmss ss UTC time in hours minutes seconds of the GPS position a a Root mean square rms value of the standard deviation of the range inputs to the navigation process Range inputs include pseudoranges and differential GN SS DGN SS corrections b b Standard deviation of semi major axis of error ellipse meters C C Standard deviation of semi minor axis of error ellipse meters d d Orientation of semi major axis of error ellipse degrees ee Standard deviation of latitude error meters f f Standard deviation of longitude error meters 0 0 Standard deviation of altitude error meters ZER Checksum lt CR gt lt LF gt Carriage return and line fe
4. 3 6 Powering the PowerMAX Receiver There are two different ways of powering the PowerMAX receiver so the first step is to terminate the power leads of the power cable or pins 6 and 8 of the serial cable There are a variety of power connectors and terminals on the market from which to choose depending on your specific requirements W e suggest that a weather tight connection and connector be used if the connection will be located outside or if it will be part of a portable system Caution Do not apply a voltage higher than 32 VDC as this will damage the receiver and void the warranty To turn on the PowerMAX receiver e Connect the red wire of the cable s power input or pin 8 on the serial cable to DC positive e Connect the black wire of the cable s power input of pin 6 on the serial cable to DC negative The PowerMAX features reverse polarity protection to prevent damage if the power leads are accidentally reversed A 1 0 A fast blow fuse situated in line of the power input of the extension cable and protects the PowerMAX receiver from power surges The fuse container should remain accessible after installation The PowerMAX will start when an acceptable voltage is applied to the power leads of the extension cable Be careful not to provide a voltage higher than the input range as this could damage the system Caution Do not operate the PowerMAX receiver with the fuse bypassed Such a modification will void the p
5. always c M 999 99 Speed over ground 000 to 999 knots U Speed over ground units u N Nautical mile h 999 99 Speed over ground 000 to 999 km h U Speed over ground units u K kilometer h ZER Checksum lt CR gt lt LF gt Carriage return and line feed 5 2 9 ZDA Data Message The ZDA message contains Universal Time information The table below breaks down the ZDA data message into its components This message has the following format GPZDA hhmmss ss dd mm yyyy xx yy cc lt C R gt lt LF gt Table 5 11 ZDA Data Message Defined Field Description hhmmss ss UTC time in hours minutes seconds of the GPS position dd Day dd 0 to 31 mm Month mm 1 to 12 yyyy Year XX Local zone description in hours xx 13 to 13 yy Local zone description in minutes yy 0 to 59 ZER Checksum lt CR gt lt LF gt Carriage return and line feed PowerMAX User Manual 27 csi wireless 5 2 10 RD1 Data Message The RD 1 message contains diagnostic information for SBAS operation The table below breaks down the RD 1 data message into its components This message has the following format RD 1 SecO fW eek W eekN um FreqMH z D SPLocked BER BER2 AGC D DSD oppler D SPStat A RM Stat D iffStatus N avC ondition cc lt C R gt lt LF gt Table 5 12 RD1 Data Message Defined Field Description SecO fW eek The second of GPS week may be a couple of seconds old W eekN um The GPS week number FregMHz The L band frequency in MHz 1475 4200 is
6. power ground on pin 6 Refer to Table 3 2 for the serial port pin out For best performance the supplied power should be continuous and clean The following table details the power specifications of the PowerMAX Table 3 1 Power Requirements Input Voltage Input Current Input Power 9 5 to 32 VDC lt 250 mA 12 VDC no antenna lt 3 W Nominal no antenna 3 5 Antenna Placement The GPS antenna included should be mounted pursuant to the following requirements e The PowerMAX receiver computes a position based upon measurements from each satellite to the location of the GPS antenna s phase center Mount the GPS antenna in the location for which you desire a position W hen choosing a location to mount the antenna please ensure that there is an unobstructed hemisphere of sky available to the GPS antenna This will ensure that GPS and SBAS satellites are not masked by obstructions potentially reducing system performance PowerMAX User Manual 12 EEE csi wireless e It is important to locate any transmitting antennas away from the GPS antenna by several feet or more This will help to ensure that tracking performance of the PowerMAX is not compromised giving you the best performance possible e Make sure that there is sufficient length of the antenna extension cable available in order to be able to connect it to the PowerMAX enclosure Do not locate the antenna where environmental conditions exceed those specified in Section 3 3
7. 4 GLL Data Message Defined sese 24 Table 5 5 GSA Data M essaie LEE 24 Table 5 6 GSA Data Message D efined sss 25 Table 5 7 GSV Data Message Defined sss 25 Table 5 8 RMC Data Message DAMEN sss sees esse enesenn 26 Table 5 9 RMC BENENE 26 Table 5 10 VTG Data Message ID Even 27 Table 5 11 RER Re sese esse eee 27 Table 5 12 RD1 Data Message Defined EE 28 dE 13 H Tea S crsa aioa a aiidis aiii 28 UE ES el EE EEE EE TE toned nooner 28 FN 29 Table 5 16 PC SI Data Message Defined sss 29 et 37 ene 38 PowerMAX User Manual ix 6 r p csi wireless Table A 1 PowerMAX Enclosure Specifications ENNEN 39 Table A 2 MGL 3 Antenna Specifications NENNEN 39 PowerMAX User Manual D Ve csi wireless Preface W elcome to the PowerMAX Manual and congratulations on choosing to purchase this high performance GPS receiver This product is based upon the successful heritage of our SLX based GPS products that are renowned for performance and reliability The PowerMAX receiver provides a high level of performance delivering sub meter positioning using either its built in SBAS demodulator built in DGPS beacon module or external corrections at up to 5 Hz output The PowerMAX features raw measurement output for post processing applications and delivers excellent phase measurement quality It also features Bluetooth and serial communications W e have written this document to assist a customer in becoming familiar with the Power MAX functionality and syste
8. COAST technology within the PowerMAX This technology is especially valuable in conditions of DGPS signal loss where the age of corrections increases for each second of signal loss Consult Section 1 7 for further information on COAST Satellite C onstellation Geometry PowerMAX User Manual 48 i csi wireless The number of satellites visible and their geometry in the sky influences positioning accuracy The Dilution of Precision D O P describes the strength of location and number of satellites in view of the receiver A low DOP indicates a strong potential for better accuracy than a high DOP Generally more satellites visible to both the reference and remote receivers will provide alower DOP any satellites seen by one receiver and not the other are not used in the position solution Additionally if the satellites are evenly soread around the receiver rather than grouped in afew regions of the sky a lower DOP stronger solution will result GPS Signal Multipath S a Satellite signals received by the GPS receiver by a reflection from an object can decrease positioning accuracy These multipath signals increase the measured range to a satellite as the signal takes a longer route to the GPS antenna Certain precautions will minimize GPS antenna sensitivity to these reflected signals O perating away from large reflective structures such as buildings or using special antennas and GPS equipment can help to reduce the impact of multipat
9. Check current restrictions imposed by power source minimum available should be gt 1 0 A Check receiver power status this may be done with an ammeter Verify that PowerMAX is locked to a valid DGPS signal this can often be done on the receiving device or with the use of Hyperterminal running on a PC e Verify that PowerMAX is locked to GPS satellites this can often be done on the receiving device or with the use of Hyperterminal running on a PC e Check integrity and connectivity of power and data cable connections Random data from e Verify that the RTC M or the Bin95 and Bin96 messages are not being output accidentally send a PowerMAX JSHOW command e Verify baud rate settings of PowerMAX and remote device match correctly e Potentially the volume of data requested to be output by the PowerMAX could be higher than the current baud rate supports Try using 19 200 as the baud rate for all devices No GPS lock e Check integrity of antenna cable e Verify antenna s unobstructed view of the sky e Verify the lock status of GPS satellites this can often be done on the receiving device or with the use of Hyperterminal running on a PC No SBAS lock e Check antenna connections e Verify antenna s unob ructed view of the sky e Verify the lock status of SBAS satellites this can often be done on the receiving device or with the use of Hyperterminal running on a PC monitor BER value No DGPS position in external s Verify that the baud rate of
10. Field Description A The number of satellites with lock and carrier phase 9 The number of satellites with ephemeris received 8 The number of satellites with healthy ephemeris 8 The number of satellites that are tracked have an ephemeris which is healthy and are above the elevation mask 9 The number of satellites above the elevation mask 7 The number of satellites with differential The number of satellites with no differential 5 2 11 PCSI 1 Beacon Status Message This message contains a variety of information relating to the status of the beacon engine inside the PowerMAX This information is included as the PC SI 1 output message from the PowerMAX is intelligently routed through the PowerMAX to the port from which the PCSI 1 message was requested PC SI C S0 PX X X Y YYY SN IM ddd R SS SN R MTP Q ID HJT Table 5 16 PCSI Data Message Defined Field Description C SU Channel 0 PXXX Resident SBX 3 firmware version Y YYY S N SBX 3 receiver serial number fff f Channel 0 current frequency M Frequency Mode A Auto or M Manual ddd MSK bit rate R RTCM rate SS Signal strength SNR Signal to noise ratio MTP Message throughput Q Quality number 0 25 number of successive good 30 bit RTC M words received ID Beacon ID to which the receiver s primary channel is tuned H Health of the tuned beacon 0 7 T PCSI 1 status output period 0 99 PowerMAX User Manual 29 csi wireless 6 Frequently Asked Que
11. Programming Manual gt JSHO W BAUD 19200 gt JSHO W BIN 1 5 0 gt JSHO W BAUD 4800 0 THER gt JSHO W ASC GPGGA 1 0 0 THER gt JSHO W ASC GPVTG 1 0 0 THER gt JSHO W ASC G PG SA 1 0 0 THER PowerMAX User Manual 32 csi wireless gt SHOW ASC GPZDA 1 0 0 THER Q How can I be sure that the configuration will be saved for the subsequent power cycle A The surest method is to query the receiver to make sure you re happy with the current configuration by issuing a JSHO W lt CR gt lt LF gt command if not make the necessary changes and repeat If the current configuration Is acceptable issue a JSAVE lt CR gt lt LF gt command W ait for the receiver to indicate that the save is complete You may power the receiver down and issue another JSAVE if you feel it s necessary however It is not required Q W hat is the best software tool to use to communicate with the PowerMAX and configure it A We use two different software applications at CSI W ireless for this application e PocketMAX Available from the CSI W ireless W eb site This application Is a very useful tool for graphically viewing tracking performance positioning accuracy and more e HyperTerminal Available on all W indows 95 98 ME 2000 and XP This tool is useful as it allows you to easily configure the PowerMAX by directly typing commands into the terminal window The output from the PowerMAX is shown simultaneously Ensure that when us
12. SS Satellites in View GPRMC 5 Hz Recommended Minimum Specific GN SS D ata GPRRE 1 Hz Range residual message GPVTG 5HZ Course O ver Ground and Ground Speed GPZDA S ck Time and Date RD1 1 Hz SBAS diagnostic information proprietary N MEA message PCSI 1 1 Hz This is a proprietary beacon status message 5 2 1 GGA Data Message The GGA message contains detailed GPS position information and is the most frequently used N MEA data message In the table below the GGA data message is broken down into its components This message takes the following form GPGGA hhmmss ss ddmm mmmm s dddmm mmmm s n qq pp p Saaaaa aa M XXXX XX M sss aaaa cc lt C R gt lt LF gt Table 5 3 GGA Data Message Defined Field Description hhmmss ss ddmm mmmmm S dddmm mmmmm S n qq pp p saaaa aa M XXXX XX M SSS aaa FCC lt C R gt lt LF gt UTC time in hours minutes seconds of the GPS position Latitude in degrees minutes and decimal minutes S N ors S for North or South latitude Longitude in degrees minutes and decimal minutes s or s W for East or W est longitude Q uality indicator 0 no position 1 undifferentially corrected position 2 differentially corrected position 9 position computed using almanac N umber of satellites used in position computation HDOP 0 0 to 9 9 Antenna altitude Altitude units M meters Geoidal separation needs geoidal height option Geoidal separation units M meters Age of differential cor
13. TN 20 4 7 Using the Serial Port for RTCM Input essen 20 5 N MEA 0183 EE eege 22 5 1 NMEA MAER ERSTEN 22 D DINE 6 E 23 LL NNN eree sacres S R 23 AE ECH E 24 5323 EE S 24 532A GST EIER 25 52 9 GSV DANE eee 25 5 20 MN lt een ee eee nee ete err ee ee ee eee 26 5 21 MED ee 26 gt TDN en 21 DANN 21 PowerMAX User Manual Vi L L csi wireless 3210 RDI Data ME Ge cee E case tacaines eae the acratioy nous tacnaenteas ssendesraseeanaeesnned scent 28 5 2 11 PCSI 1 Beacon Status Meseage ENNEN 29 6 Frequently Asked Q uestionS sese esse eee eee eee 30 E DE E 16T T 30 62 Support and Repar EEE 31 GC Rent ie e N DEE 31 6 4 Power Communication and Configuration sss esse esse esse eee eee 32 05 GPS Reception and PE ON e sesope aN AEE EaR REA 33 6 6 SBAS Reception and PerTormantg sese esse eee eee eee eee 33 6 7 Beacon Reception and Performance eee 34 E 35 69 External LOTECHONS stances aac cc dents cecaenra aaao aiaa iaai 35 CO TE EE ER 7 H rels TAC UN EE RE ET EE NE RNA 37 LLE Troubleshooting eet EEE aaa Ta 37 2 Using THE LEDS NTN 37 NNN 39 R leer ee Aho EE EE E eT 41 Appendix C Introduction to GPS SBAS and Beacon ENEE 44 Appendix D NE 58 ME a E O E E E E E E eens 60 PowerMAX User Manual vii csi wireless List of Figures TINN 2 Figure 3 1 Cahe Mtera E 11 Figure 3 2 DBO Socket NENNE 14 Figure 3 3 PowerMAX Front PORE vr 16 Figure B 1 Serial Interface ccssscssssssssssscssssvsss
14. can lead to incompletely corrected error source that could degrade positioning accuracy with increased distance from the base station W AAS and SBAS use a different approach using a network of reference stations in strategic locations to take measurements and model the real time ionosphere Updates the ionospheric map are sent on a continual basis to ensure that as the activity of the ionosphere changes with time the user s positioning accuracy will be maintained Compared to using a DGPS beacon the effect of geographic proximity to a single reference station is minimized resulting in more consistent system performance throughout all locations within the network Correction Latency The latency of differential corrections to a lesser extent affects the achievable positioning accuracy at the remote receiver since the magnitude of SA was turned to zero in year 2000 Latency is a function of the following e The time it takes the base station to calculate corrections e The data rate of the radio link e The time it takes the signal to reach the user e The time required for the remote differential receiver to demodulate the signal and communicate it to the GPS receiver e Any data loss that occurs through reception problems Most of these delays require less than a second though in some instances depending upon the amount of information being transferred overall delays of three to five seconds may occur The effect of latency is mitigated by new
15. computer that does not support Bluetooth natively you often can supplement your computing device with a Bluetooth card or dongle Caution By default the PowerMAX receiver offers 5 3 VDC across its RF connector to power an active GPS antenna s low noise amplifier LNA Connection to a GPS antenna that doesn t support a 5 VDC input could damage the antenna The following figure shows the various connections required for the PowerMAX Figure 1 1 Cable Interface 1 4 Configuring the PowerMAX The PowerMAX has two primary communication ports referred to as Serial and Bluetooth The Serial and Bluetooth ports are fully independent and you may configure each port to have different messages output at different rates The Serial port may be configured for external correction input Or output binary message information or even RTCM corrections from a SBAS demodulator Note The serial port is available via the single DB9 female connector located on the rear panel labeled Data The pin out for this connector is provided in Table 1 5 1 5 NMEA 0183 Message Interface The PowerMAX uses aN MEA 0183 interface for interfacing which allows you to easily make configuration changes by sending text type commands to the receiver W here appropriate relevant commands for making the configuration changes are discussed in the following chapters The Programming Manual however is devoted to describing the N MEA interface in detail You can do
16. e D if PowerMAX User Manual 30 csi wireless A W e suggest that you contact your dealer to see if they have a unit available with e D if activated for your testing 6 2 Support and Repairs Q How do you recommend that I pursue support to solve a problem that can t isolate A W e recommend that you contact your dealer first W ith their experience with this and other products from CSI W ireless they re likely to help you isolate a problem If the issue is beyond the capability or experience of your dealer either they or you can speak with a Technical Service Representative from CSI W ireless Q Can I contact CSI W ireless directly regarding technical problems A Yes however we recommend that you speak to your dealer first as they would be your local support They may be able to solve your problem more promptly than us due to their location and experience with our equipment 6 3 Troubleshooting Q What do I do initially if I have a problem with the operation of the PowerMAX module A Try to isolate the source of the problem Problems are likely to fall within one of the following categories It s important to review each in detail to remove each from being a suspect source of the problem e Power communication and configuration e GPS reception and performance e Beacon reception and performance e SBAS reception and performance e External corrections e Installation The questions in the following secti
17. for PowerMAX cables PowerMAX User Manual 11 EEE csi wireless Avoid running cables in areas of excessive heat Keep antenna cables away from corrosive chemicals Do not run the extension cable through door or window jams Keep the cable away from rotating machinery Do not bend excessively or crimp the extension cable Be careful not to apply tension to the cable Remove unwanted slack from the cable at the opposite end to the antenna Secure the cable route using plastic tie wraps W arning Improperly installed cables near machinery can be dangerous 3 3 Environmental Requirements The equipment supplied with the PowerMAX system has specific environmental limits that you should ensure are met when storing and using the system The PowerMAX receiver is designed to be stored between 40 C and 85 C The operating temperature range is 30 C and 0 C The Pow eri A is specified to operate with humidity up to 95 non condensing The antennas are designed to operate in an outdoor environment with 100 relative humidity condensing 3 4 Power Requirements The PowerMAX is powered via a power cable that interfaces to the enclosure s Power connector This system accepts an input voltage between 9 5 and 32 VDC There is asecond option for powering the PowerMAX It is possible to power it through the serial port labeled D ata instead of through the power connector The PowerMAX is specially set up to receive power on pin 8 and
18. information to GPS users at UHF 1 575 GH 2 frequencies that allows user equipment to calculate a range to each satellite GPS is essentially a timing system ranges are calculated by timing how long it takes for the coded GPS signal to reach the user s GPS antenna To calculate a geographic position the GPS receiver uses a complex algorithm incorporating satellite coordinates and ranges to each satellite Reception of any four or more of these signals allows a GPS receiver to compute 3D coordinates Tracking of only three satellites reduces the position fix to 2D coordinates horizontal with fixed vertical The GPS receiver calculates its position with respect to the phase center of the GPS antenna The latitude longitude and altitude of the antenna are referenced according to the W orld Geodetic System 1984 ellipsoid W GS 84 GPS Services The positioning accuracy offered by GPS varies depending upon the type of service and equipment available For security reasons two GPS services exist the Standard Positioning Service SPS and the Precise Positioning Service PPS The SPS uses a code modulated onto the signal for measurements and is referred to as the Coarse Acquisition code C A code The US Department of Defense DoD reserves the PPS for use by its personnel and authorized partners The PPS uses a different code than the SPS referred to as the Precise C ode P code and contains more resolution than the C A code The DoD provid
19. may cause harm to you PowerMAX User Manual xiii a fe EEE csi wireless 1 Quick Start The purpose of this chapter is to help you get your PowerMAX receiver running quickly This chapter is not intended to replace the balance of this reference manual and it assumes that you have a reasonable amount of knowledge with installation and operation of GPS navigation systems If you are new to GPS and SBAS we recommend that you consult Appendix C for further information on these services and technology The PowerMAX receiver system is composed of two main pieces PowerMAX receiver and the GPS beacon antenna 1 1 Receiving Your Shipment If you find that any of these items are damaged due to shipment please contact the freight carrier immediately for assistance 1 2 Unpacking Your PowerMAX System W hen you unpack your PowerMAX system please ensure that it is complete by comparing the parts received against the packing slip Unless your system has been equipped differently than a standard PowerMAX system you should find the following parts in your system One PowerMax Receiver P N 803 0030 01A One MGL 3 Antenna P N 804 3003 05A One Magnetic Mount P N 725 0007 014 One 3 Meter Power Cable P N 054 0009 000 One 3 Meter Data Cable P N 050 0011 022 One 5 Meter Antenna Cable P N 052 0005 000 One Manual CD P N 132 0127 000 containing the PowerMAX Reference Manual Note If for some reason you find a discrepancy be
20. the PowerMAX s serial port and that the signal grounds are connected 6 10 Installation Q Does it matter where I mount the PowerMAX s antenna PowerMAX User Manual 35 csi wireless A Yes the main consideration is that it must have an open hemisphere of sky for satellite tracking Additionally the position that it computes is referenced to the center of the antenna It should be placed in the location for which you would like a position O ften this is the centerline of a vehicle or on a pole mount for georeferencing Q Will the method of mounting the antenna magnetic mount surface mount or the pole mount affect PowerMAX performance A No all methods of mounting the PowerMAX are equally suited for its use Q Can I use a vehicle s power system to operate the PowerMAX system or do I need a dedicated battery A Yes you can the internal power supply of the PowerMAX is designed for use with industrial vehicles PowerMAX User Manual 36 csi wireless 7 Troubleshooting 7 1 Troubleshooting Checklist Use the following checklist to troubleshoot anomalous PowerMAX system operation The following table provides a problem symptom followed by a list of possible solutions Table 7 1 Troubleshooting Symptom Possible Solution Receiver fails to power Verify polarity of power leads Check 1 0 A in line power cable fuse Check integrity of power cable connections Check power input voltage 9 5 to 32 VDC
21. the use of forward error correction algorithms one symbol is composed of two bits The BER value for both SBAS receiver channels is available in the RD1 NMEA data message described in detail in the Programming M anual A lower BER indicates that data is being successfully decoded with fewer errors providing more consistent throughput The bit error rate has a default no lock value of 500 or more As the receiver begins to successfully acquire the signal it will result in a lower bit error rate For best operation this value should be less than 150 and ideally less than 20 Space Based Augmentation Systems broadcast an ionospheric map on a periodic basis that may take up to 5 minutes to receive upon startup The PowerMAX uses the GPS broadcast ionospheric model until it has downloaded the SBAS map which can result in lower performance as compared to when the map has been downloaded This will be the case for any GPS product supporting SBAS Services PowerMAX User Manual 6 a EE csi wireless Caution When the map has been downloaded you may observe a position jump due to the potential difference between the GPS ionospheric model and the ionospheric SBAS map To minimize the impact of this issue on your use of the PowerMAX you may wish to wait up to five minutes before using the PowerMAX or issue the SJQUERY GUIDE lt C R gt lt LF gt message to ask the PowerMAX if it feels performance will be sufficient for operation 2 3 Radi
22. used for SBAS D SPLocked 1 if D SPStat 1B or 1F BER BER2 Bit error rate bit error rates are given for both SBAS satellites being tracked AGC L band Signal strength DDS 0 0 for SBAS Doppler 0 for SBAS D SPStat A status bit mask for the DSP tracking of SBAS ARM Stat A status bit mask for the ARM GPS solution D iffStatus The SBAS PRN of the satellite in use NavCondition A series of hex character fields which is read from right to left with each field representing the number of GPS satellites satisfying a certain condition all of which conditions are required if the satellite is to be used in the solution CC Checksum lt CR gt lt LF gt Carriage return and line feed The following table describes the DSP status The DSP status should be 17 1B or 1F when SBAS tracking has been achieved Table 5 13 DSP Status Field Description 01 Carrier lock 02 BER is ok on at least one SBAS satellite 04 Frame synchronization has been achieved on the second satellite 08 Frame synchronization has been achieved on the first satellite 10 Carrier lock The following table describes the ARM status Table 5 14 ARM Status Field Description 01 GPS lock 02 DGPS valid data 04 The ARM processor has lock 08 DGPS solution 10 DGPS solution is good 20 N ot used 40 N ot used PowerMAX User Manual 28 csi wireless An example of the N avC ondition is presented in the following table for the 179889A value Table 5 15 NavCondition
23. user s location This Spatial decorrelation of errors can result in a relative position offset from the absolute coordinates of the remote receiver This offset may be as much as one meter for every 100 km 62 miles between the base station and remote receiver The causes of decorrelation are e GPS satellite orbit errors significant e lonospheric errors potential to be most significant depending on level of activity e Tropospheric errors less significant GPS satellite orbit errors are typically a greater problem with local area differential systems such as that of radiobeacons The decorrelation effect is such that the satellite s orbit error projects onto the reference receiver and remote receiver s range measurements differently As the separation between the receivers increases the orbit error will not project onto the ranges in the same manner and will then not cancel out of the measurement differencing process completely SBAS networks with the use of multiple base stations are able to accurately compute the orbit vector of each satellite The resulting corrector Is geographically independent so minimal decorrelation occurs with respect to position within the network The ionosphere and the troposphere both induce measurement errors on the signals being PowerMAX User Manual 47 S a csi wireless received from GPS The troposphere is the humid portion of the atmosphere closest to the ground Due to it humidity refraction o
24. AX simultaneously such as NMEA and binary or NMEA and RTCM ensure that the software used for logging and processing of the data has been designed to correctly parse the different data types from the single stream of data Alternatively you may also use the two ports serial and Bluetooth to separate the different data types and at different output rates 4 2 1 NMEA 0183 Interface N MEA 0183 is acommunications standard established by the N ational Marine Electronics Association N MEA and provides data definitions for a variety of navigation and related equipment Such instruments supported include gyrocompasses Loran receivers echo sounders GPS receivers and more NMEA functionality is virtually standard on all GPS equipment available N MEA has an ASCII character format that allows you to read the data via terminal software on the receiving device if possible O ne second of example N MEA data from the PowerMAX follows SGPGGA 144049 0 5100 1325 N 11402 21729 1 07 1 0 1027 4 M 0 M 4 0100 61 SGPVTG 308 88 7 308 88 M 0 041 N 0 08 K 42 SEFGSV 3 1 10 02 73 087 54 04 00 172 39 07 66 202 54 08 23 147 48 19 GPGSV 3 2 10 09 23 308 54 11 26 055 54 15 00 017 45 21 02 353 45 78 SEPGSV 3 3 10 26 29 257 51 27 10 147 45 rrrrr 74 PowerMAX User Manual 17 SE csi wireless The PowerMAX supports a variety of standard and proprietary NMEA messages These messages are used to configure the PowerMAX and also contain the required infor
25. Bluetooth is NMEA data that provides a variety of information such as position speed satellites tracked and more This is the normal data Output and mode of operating the PowerMAX To establish communications between the PowerMAX receiver and your data logging or navigation device in this mode of operation you must e Connect Pin 2 transmit TX of the PowerMAX Serial Port to the receive pin RX of the data logging or navigation device e Connect Pin 3 receive RX of the PowerMAX Serial Port to transmit pin TX of the other device if it is able to configure the PowerMAX Otherwise this connection is optional e Connect Pin 5 signal ground of the PowerMAX Serial Port to the signal return or of the external device Figure B 1 illustrates the required interface between the PowerMAX and an external device PowerMAX DATA External Device Figure B 1 Serial Interface Note For successful communications the baud rate of the PowerMAX port must be set to match that of the data logging or monitoring device The PowerMAX only supports an RS 232C serial port Refer to the Programming Manual for PowerMAX User Manual 41 csi wireless instructions related to setting the PowerMAX baud rate RTCM Data Output To output only RTCM correction data from the internal SBAS correction source from the Serial or Bluetooth ports of the PowerMAX use the following procedure e Turn off all NMEA and binary messages using the JO FF
26. EA and binary message of the PowerMAX can be set independently with a maximum that is dependant upon the message type Some messages have a 1 Hz maximum for example while others are 5 Hz Higher update rates are valuable for applications where higher speeds are present such as aviation or more frequent updates are required for manual navigational tasks such as Agricultural Guidance 2 2 SBAS The following sections describe the general operation and performance monitoring of the SBAS demodulator within the PowerMAX receiver 2 2 1 Automatic Tracking The SBAS demodulator featured within the PowerMAX will automatically scan and track the SBAS satellite signals This automatic tracking allows the user to focus on other aspects of their application rather than ensuring the receiver is tracking SBAS correctly The SBAS demodulator features two channel tracking that provides an enhanced ability to maintain acquisition on a SBAS satellite in regions where more than one satellite is in view This redundant tracking approach will result in more consistent acquisition of a signal when in an area where signal blockage of either satellite is possible 2 2 2 SBAS Performance The performance of the SBAS receiver is described in terms of a differential LED SBAS requires a line of sight to the SBAS satellites in order to acquire the signd The BER number indicates the number of unsuccessfully decoded symbols in a moving window of 2048 symbols Due to
27. L OR CONTINGENT DAMAGES EVEN IF CSI WIRELESS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES WITHOUT LIMITING THE FOREGOING CSI WIRELESS SHALL NOT BELIABLE FOR ANY DAMAGES OF ANY KIND RESULTING FROM INSTALLATION USE QUALITY PERFORMANCE OR ACCURACY OFANY PRODUCTS Governing Legislation To the greatest extent possible this warranty shall be governed by the laws of the State of Arizona In the event that any provision hereof is held to be invalid by a court of competent jurisdiction such provision shall be severed from this warranty and the remaining provisions shall remain in full force and effect Obtaining Warranty Service In order to obtain warranty service the end purchaser must bring the Product to a CSI W tireless approved dealer along with the end purchaser s proof of purchase For any questions regarding warranty service or to obtain information regarding the location of any of CSI W ireless s dealers contact CSI W ireless at the following address CSI W ireless Inc 4110 9 Street SE Calgary AB T2G 3C4 C anada Telephone number 1 403 259 3311 Fax number 1 403 259 8866 E mail address techsupport csi wireless com PowerMAX User Manual iV Ze csi wireless Table of Contents Kj ao EEE EE EE E taser tees ceectuenecans viii BE WE IX Ne E XI BBS Tr ste E D Customer e E xii Worn EE EE xiii DOCUMENT C MN xiii Notes Cautions and Warnings ae EEN AKA aaa a xiii L CLUS EEE EE 1 1 1 Receiving Your ll
28. S coverage as provided by the currently leased Inmarsat Atlantic O cean Region W est AO R W and Pacific O cean Region PO R geostationary satellites This figure approximates signal coverage with white shading where each satellite is 5 elevation or greater Figure C 1 also shows additional contours for 10 15 and 20 elevations W ithin the white shaded coverage area at least one of the two satellites is available by line of sight W ithin the overlap area both satellites may be accessible Although there is geographic coverage at higher latitudes practical usage of W AAS will be limited to environments where a relatively consistent line of sight to either of the Inmarsat satellites from the PowerMAX system Figure C 2 presents approximate EGN OS System Test Bed coverage provided by the leased Inmarsat Atlantic O cean Region East AO R E and Indian O cean Region 10 R satellites This figure approximates signal coverage with white shading where each satellite is 5 elevation or greater Figure C 2 also shows additional contours for 10 15 and 20 elevations W ithin the white shaded coverage area at least one of the two satellites is available by line of sight W ithin PowerMAX User Manual 51 csi wireless the overlap area both satellites may be accessible Virtually all of Europe part of northern Africa and into the Middle East is covered with at least one signal Most of Europe is covered by two signals Note
29. The Programming Manual describes the baud rate change command 3 8 Bluetooth Interface Bluetooth is a wireless communication technology that enables seamless data connections between a wide range of devices through short range digital two way radio In the case of the PowerMAX it Is equipped with Bluetooth technology and requires another Bluetooth device with which to communicate a Bluetooth capable PDA for example The Bluetooth wireless module inside the PowerMAX is a power class 1 device supporting version 1 1 of the Bluetooth standard and has been certified The bluetooth port should not be used for firmware updates It is recommended you use the serial port for any software updates PowerMAX User Manual 14 csi wireless 3 9 Factory Default Parameters The following table shows the application firmware present within the PowerMAX engine Table 3 3 Firmware Applications W AAS SBAS Default BEACON The following table outlines the default communic ation parameters of the PowerMAX receiver Table 3 4 Default Port Settings Port Baud Rate Data Bits Parity StopBit Interface Level Serial and 9600 8 None 1 RS 232C Bluetooth Table 3 5 Default GPS NMEA Message Output Port GPS NMEA Messages Update Rate Serial GGA GSV VTG ZDA 1 Hz Bluetooth GGA GSV VTG ZDA 1 Hz Table 3 6 Default Parameters Max DGPS Age Elevation Mask 1800 seconds 5 Note Any changes you make to the PowerMAX configuration need to be sav
30. adcasting range of a 300 kHz beacon is dependent upon a number of factors including transmission power free space loss ionospheric state surface conductivity ambient noise and atmospheric losses The strength of a signal decreases with distance from the transmitting station due in large part to spreading loss This loss is aresult of the signal s power being distributed over an increasing surface area as the signal radiates away from the transmitting antenna PowerMAX User Manual 55 S a csi wireless The expected range of a broadcast also depends upon the conductivity of the surface over which it travels A signal will propagate further over a surface with high conductivity than over a surface with low conductivity Lower conductivity surfaces such as dry infertile soil absorb the power of the transmission more than higher conductivity surfaces such as sea water or arable land A radiobeacon transmission has three components a direct line of sight wave a ground wave and a sky wave The line of sight wave is not significant beyond visual range of the transmitting tower and does not have a substantial impact upon signal reception The ground wave portion of the signal propagates along the surface of the earth losing strength due to spreading loss atmospheric refraction and diffraction and attenuation by the surface over which it travels dependent upon conductivity The portion of the beacon signal broadcast skywards is know
31. ailable GPS satellites in view and the SBAS differential service If SBAS is not available in your area you may use either beacon or an external source of RTC M SC 104 differential corrections If you choose to use an external source of correction data you will need to ensure that the external source supports an eight data bit no parity and one stop bit configuration 8 N 1 and a baud rate between 4800 and 38400 baud This chapter describes the various modes of operation and features of your PowerMAX receiver 2 1GPS The following sections describe the general operation of the PowerMAX GPS module 2 1 1 Satellite Tracking The PowerMAX automatically searches for GPS satellites acquires the signal and manages the associated navigation information required for positioning and tracking This is a hands free mode of operation Satellite acquisition quality is described as a signal to noise ratio SNR A higher SNR is indicative of better quality signal reception Note The GPS engine is always operating regardless of the DGPS mode of operation 2 1 2 Positioning Accuracy The PowerMAX Is asub meter horizontally 95 accurate product under ideal conditions minimum error W hen characterizing receiver performance C SI W ireless gathers a 24 hour data set of positions in order to log the diurnal environmental effects and also to log 2 full GPS constellation changes Data sets shorter than 24 hours tend to provide more optimistic resu
32. al accuracy of Products as stated in CSI W ireless literature and or Product specifications serves to provide only an estimate of achievable accuracy based on e Specifications provided by the US Department of Defense for GPS Positioning e GPS OEM Receiver specifications of the appropriate manufacturer if applicable and e DGPS service provider performance specifications CSI W ireless reserves the right to modify Products without any obligation to notify supply or install any improvements or alterations to existing Products No Other Warranties THE FOREGOING WARRANTY ISEXCLUSIVE OF ALL OTHER W ARRANTIES W HETH ER WRITTEN ORAL IMPLIED OR ARISING BY STATUTE COURSE OF DEALING OR TRADE USAGE IN CONNECTION WITH THE DESIGN SALE INSTALLATION SERVICE OR USE OF ANY PRODUCTSORANY COMPONENTSTHEREOF INCLUDING BUT NOT LIMITED TO ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPO SE Limitation of Liability PowerMAX User Manual lil csi wireless THEEXTENT OF CSI W IRELESS S LIABILITY FOR DAMAGESOFANY NATURETO THE END PURCHASER OR ANY OTHER PERSON OR ENTITY WHETHER IN CONTRACT OR TORT AND WHETHER TO PERSONSOR PROPERTY SHALL IN NO CASE EXCEED IN THE AGGREGATE THE COST OF CORRECTING THE DEFECT IN THE PRODUCT OR AT CSI WIRELESSS OPTION THE COST OF REPLACING THE DEFECTIVE ITEM IN NO EVENT WILL CSI WIRELESS BE LIABLE FOR ANY LOSSOF PRODUCTION LOSS OF PROFITS LOSSOF USEOR FOR ANY SPECIAL INDIRECT INCIDENTAL CONSEQUENTIA
33. al xi a Se csi wireless a Chapter 5 NMEA 0183 Messages describes the subset of NMEA 0183 commands and queries supported by the PowerMAX receiver Chapter 6 Frequently Asked Q uestions This chapter provides answers to frequently asked questions about the PowerMAX receiver Chapter 7 Troubleshooting provides you with diagnostic information to aid in determining a source of difficulty for a particular installation Appendix A Specifications details the technical characteristics of the PowerMAX system Appendix B Interface provides instructions to interface the PowerMAX with external devices Appendix C Introduction to GPS and SBAS provides both general and specific information relating to GPS and SBAS Appendix D Resources This appendix lists anumber of different resources that may be useful for the advanced user The Index provides a listing of the locations of various subjects within this manual Customer Service If you encounter problems during the installation or operation of this product or cannot find the information you need please contact your dealer or CSI W ireless Customer Service The contact numbers and e mail address for CSI W ireless Customer Service are Telephone number 1 403 259 3311 Fax number 1 403 259 8866 E mail address techsupport csi wireless com Technical Support is available from 8 00 AM to 5 00 PM Mountain Time Monday to Friday To expedite the support proce
34. appear lower on the horizon they may be more prone to being masked by terrain foliage buildings or objects resulting in signal loss The further that you are away from the equator and the satellite s longitude will cause the satellite to appear lower on the horizon Fortunately the CSI W ireless CO AST Technology helps alleviate this problem by maintaining system performance when W AAS SBAS signal loss occurs for extended periods of time More information on COAST is provided in Section 1 7 The EGNOS System Test Bed ESTB also referred to as EGNOS in this document uses two geostationary satellites separate from W AAS however in this case they are located over the Atlantic and Indian O ceans Similar to W AAS the satellites may appear lower on the horizon depending on your geographic position on land The further that you are away from the equator and the satellite s longitude will cause the satellite to appear lower on the horizon If the EGNOS signal becomes unavailable due to obstruction COAST technology helps to maintain system performance during times of differential outage W hen using SBAS correction data the PowerMAX is able to provide you with the azimuth and elevation of the SBAS available satellites via a N MEA serial port command to aid in determining their position with respect to the built in antenna More about this feature is described in Section 5 5 2 WAAS and ESTB Coverage Figure C 1 depicts the current W AA
35. at your risk O ther government agencies are in the process of developing compatible SBAS systems for their respective geographic regions In Europe the European Space Agency the European Commission and EURO CON TRO are jointly developing the European Geostationary O verlay System EGNOS In Japan the MTSAT Satellite based Augmentation System MSAS is in progress of development by the Japan Civil Aviation Bureau JCAB China has a similar program for a SBAS and the service is named the Chinese Satellite N avigation Augmentation System SN AS The PowerMAX is capable of receiving correction data from all compatible SBAS EGNOS is currently in a prototyping phase referred to as the EGN O S System Test Bed EST B and which has been broadcasting a test signal since February 2000 EGNOS should be used at PowerMAX User Manual 49 E csi wireless your risk only MSAS has yet to begin transmitting data publicly SN AS is transmitting correction data currently on a military communication channel and is expected to become publicly available in the near future W arning Although W AAS has successfully passed a 21 day test and is publicly available its use is at your risk and discretion EGNOS is not currently broadcasting with any form of certification or approval It may produce misleading information and its use is entirely at your risk and discretion MSAS may begin broadcasting a preliminary signal as early as the end of 2002 Ho
36. ation Basics This chapter introduces the general operational features of the PowerMAX system operating modes and receiver default operating parameters 4 1 Powering PowerMAX As described in Chapter 2 Introduction the PowerMAX is powered by connecting the red and black power leads or pins 6 and 8 to a9 5 to 32 VDC power source and ground Once both leads are connected the PowerMAX will be immediately powered W ith the application of power the PowerMAX system will proceed through an internal start up sequence however it will be ready to communicate immediately W hen installed such that the antenna has an unobstructed view of the sky the PowerMAX will provide a position quickly within approximately 60 seconds SBAS lock requires approximately 30 seconds to acquire Beacon lock requires approximately 60 seconds to acquire Note It can take up to 5 minutes for a full ionospheric map to be received from SBAS Optimum accuracy will be obtained once the PowerMAX is processing corrected positions using complete ionospheric information 4 2 Communicating with PowerMAX The PowerMAX features two serial ports that may be configured independently from each other Ports Serial and Bluetooth The ports may be configured for any mixture of N MEA 0183 binary and RTCM SC 104 data The usual data output is limited to N MEA data messages since these are industry standard Note If you require different data types to be output from the PowerM
37. ce 9 H Humidity 12 IC D GPS 200 46 Installation Connecting to External D evices 13 14 Environmental Considerations 12 Placement 12 Power Considerations 12 L LED Indicators 15 M Multipath 49 N N MEA 0183 17 22 N MEA 0183 messages 22 P Port Defaults 15 Positioning Accuracy 5 Post Processing 8 Power Cable Fuse 13 R RTCM SC 104 46 S SBAS Performance 6 Selective Availability SA 45 Serial Port Defaults 3 Serial Port Pin out 4 14 Signal to N oise Ratio SNR 8 60 T Temperature 12 Troubleshooting 37 Tune Mode Automatic Beacon Search ABS 7 8 Manual 8 W AAS Automatic Tracking 6 U Update Rates 6 PowerMAX User Manual ill i csi wireless W WAAS Bit Error Rate 6 Receiver Performance 6 W GS 84 44 www csi wireless com XIII 61
38. con in memory so that it is available upon Subsequent power up 2 4 1 4 Manual Tracking In Manual tune mode you may select a specific frequency and bit rate for the receiver to tune or specify the frequency only allowing the PowerMAX to identify the correct MSK bit rate on its own This mode of operation is most useful when working in an area where you know the frequency though not necessarily the MSK bit rate of the closest beacon 2 4 2 Receiver Performance The Signal to N oise Ratio SN R best describes the internal SBX 3B beacon receiver performance The SNR measured in dB is the height of the signal above the noise floor The higher the SNR the more successfully the beacon receiver is demodulating the signal Table 2 1 describes the beacon receiver quality of reception with respect to the SN R reading Table 2 1 Beacon Receiver Performance SNR Reading Reception Description Approximate Data Throughput gt 25 Excellent 100 data throughput 20 to 25 Very Good 100 data throughput 15 to 20 Good Good data throughput up to 100 10 to 15 Stable Moderate to good data throughput 7 to 10 Intermittent Low data throughput lt 7 No Lock No data throughput 2 5 COAST Technology The PowerMAX receiver incorporates the CSI W ireless CO AST technology that allows it to operate with old correction data for up to 30 to 40 minutes or more without significant accuracy degradation The feature s performance is attributed to sophisticated a
39. corrections Carrier phase corrections are not used with this form of differential technique Post processing This method is often used when either higher accuracy than achievable through conventional differential is needed or a conventional form of real time corrections is not available in the region where the rover receiver is being operated Depending on receiver hardware and the methodology used for post process performance can be from many centimeters to millimeter precision A variety of 3 party software packages are available to post process GPS raw measurement data The PowerMAX can be configured to output raw measurement data at rates of up to 5 Hz in aproprietary format This data can be converted to an industry standard RIN EX format if needed Real Time Kinematic This method uses more sophisticated techniques to resolve the number of wavelengths between the satellite and the user to provide centimeter level positioning or better in real time This technique uses high end receiver hardware antennas and internal operating software to compute accurate position solutions The compromise with this method of differential correction is increased system complexity cost and operating constraints The PowerMAX includes two primary sources of conventional real time corrections beacon DGPS and Space Based Augmentation System SBAS External corrections may also be input to the PowerMAX for situations where either internal correction servic
40. ed 5 2 5 GSV Data Message The GSV message contains GPS satellite information N ull fields occur where data is not available due to the number of satellites tracked The Table below breaks down the GSV data message into its components This message has the following format G PG SV t m n li ee aaa ss Il ee aaa Ss cc lt C R gt lt LF gt Table 5 7 GSV Data Message Defined Field Description t Total number of messages m Message number m 1 to 3 n Total number of satellites in view ii Satellite number ee Elevation in degrees ee 0 to 90 aaa Azimuth true in degrees aaa 0 to 359 SS SN R dB 30 ss 0 to 99 TCC Checksum lt CR gt lt LF gt Carriage return and line feed PowerMAX User Manual 25 csi wireless 5 2 6 RMC Data Message The RMC message contains recommended minimum specific GPS data The table below breaks down the RMC data message into its components This message has the following format GPRMC hhmmss ss a ddmm mmm n dddmm mmm w z z y y ddmmyy d d v KCC eL R gt lt LF gt Table 5 8 RMC Data Message Defined Field Description hhmmss ss a ddmm mmmmm n dddmm mmmmm UTC time in hours minutes seconds of the GPS position Status Is valid if a A status is invalid if a V Latitude in degrees minutes and decimal minutes S N ors S for North or South latitude Longitude in degrees minutes and decimal minutes W S Eors W for East or W est longitude Z Z Ground speed in knots
41. ed with the SJSAVE NMEA command in order to be present for a subsequent power cycle 3 10 LED Indicators The PowerMAX features diagnostic LEDs that provide a quick indication of the receiver s status These LEDs are visible on the front panel display The five diagnostic LEDs visible on the front panel display of the PowerMAX provide the following information PowerMAX User Manual 15 Kl csi wireless Table 3 7 LED Indicator Definitions LED Color Function PW R Red Power indicator when the PowerMAX is powered this LED will illuminate GPS Yellow GPS lock indicator this LED will blink a few times on startup O nce the PowerMAX achieves a solid GPS lock this LED will remain illuminated If this LED continues to blink it could be an indication of a receiver hardware failure DIFF Yellow Differential lock indicator this indicator will illuminate continuously when the PowerMAX has achieved a solid SBAS or beacon lock with better than a 150 bit error rate BER or when it is successfully receiving externally input RTC M corrections If the SBAS BER is higher than 150 but the receiver is still locked this LED will blink showing that lock is marginal DGPS Green DGPS position indicator this LED will illuminate when the receiver has achieved a differential position and the psuedorange residuals are below that set with the JLIMIT command The default value is a psuedorange residual of better than 10 0 meters If the residual va
42. eiver makes distance measurements in real time to each of the GPS satellites The measured ranges include the errors present in the system The base station receiver calculates what the true range without errors Knowing its coordinates and those of each satellite The difference between the known and measured range for each satellite is the range error This error is the amount that needs to be removed from each satellite distance measurement in order to correct for errors present in the system The base station transmits the range error corrections to remote receivers in real time The remote receiver corrects its satellite range measurements using these differential corrections yielding a much more accurate position This is the predominant DGPS strategy used for a majority of real time applications Positioning using corrections generated by DGPS radiobeacons will provide a horizontal accuracy of 1 to 5 meters with a 95 confidence More sophisticated short range DGPS systems 10 to 15 km can achieve centimeter level accuracy but are expensive and often limited to precise survey applications due to technical constraints on their use DGPS Format For manufacturers of GPS equipment commonality is essential to maximize the utility and compatibility of a product The governing standard associated with GPS is the Interface C ontrol Document IC D GPS 200 maintained by the US DoD This document provides the message and signal structure informati
43. el 1 1 2 Unpacking Your PowerMAX System ccsssssrssssrssssrssssssrsssersessssrsssersesercesssesesersesersevesersessrsavetersatensanensesenenses 1 EG So le let 1 1 4 Configuring the POwerMAX EE 2 1 5 NMEA 0183 Message IME Bee sala gnasbidoede iu intanbaadaud batcansarasiinatys 2 16 Binary Message INTErTaCE ssssossinennnenaoep aa S 3 TT MN 3 18 PNAN 3 Nee 4 2 MIN 5 Stee 5 NETTENE 5 TE PN 5 12 MN er 6 NN 6 22 Automatic Te 6 2 2 2 SBAS ag E 6 2 FONDET 7 24 BENN 7 2A MR Oe e E 7 2 4 2 Receiver tg Ee E 8 5 COAST TN 8 6 Post elai sunsorsisiidstninnon ha i ari 9 2 7 Evaluating PowerMAX PerfOrMance cccssesssssessssesssserssssrsssscersesercesscersaseesavecerseseesaverceseteesaversesatersasersesenenses 9 PowerMAX User Manual V wf ge csi wireless 3 S EE ET ee er ee ere 11 3L System Parts E 11 3A ee ut e na E E 11 3 2 1 Routing and Securing hg He 11 3 3 Environmental Requirements sse esse eee eee eee eee eee eee 12 34 PN NNN 12 SEENEN 12 3 6 Powering the PoWerMAX Recevet sse essen eee 13 TN 13 3 8 EN 14 3 9 Factory Default NET 15 ENN cpr cree ere mercenary meen are erect ee ee re ee ee ee 15 d EEGENEN 17 4l Powering FPOWerMA NT 17 4 2 Communicating with Bower X sss esse esse eee 17 42A NMEA 0189 las lt re En E 17 4 2 2 Binary Interface EE ERE EE 18 423 RTCM SC 104 Protocol EEN 18 4 3 Configuring POW CFM A E 19 2 FANT 19 4 5 CNN EMNENE 20 EE Eau ghet EE ei canes tartans anus 20 4 6 Saving PowerMAX
44. ell as other correction services A e Dif will perform with a similar level of performance as other differential services at first There will be a slow drift to the positioning performance with increasing time W e normally allow e D if to age for a maximum of 30 to 40 minutes however it s up to you on how long you will allow it to age A simple update to the reference position will again provide best performance Q Will e Dif correct for multipath A No there s no method of differentially correcting multipath signals There s only ways of reducing their impact on the measurements gathered by the receiver 6 9 External Corrections Q My Pow eri A X system doesn t appear to be using corrections from an external correction source what could be the problem A This could be due to anumber of Issues Make sure that the corrections are of an RTCM SC 104 protocol Make sure that the differential source Is set to receive RTC M by issuing a JDIFF T HIS lt cr gt lt lf gt on the Serial port Check to see that the baud rates of the port used by the PowerMAX matches that of the external correction source The external correction source should be using an 8 data bit no parity and 1 stop bit serial port configuration Inspect the cable connection to ensure there s no sign of damage Check the pin out information for the cables to ensure that the transmit line of the external correction source is connected to the receive line of
45. en the aircraft lands Provided that the user feels that it s efficient to do so e D if can be successfully used in geographic regions where the only differential services available are subscription based E Dif in this application would require an initialization as frequently as the user feels is necessary to maintain a level of performance that they re comfortable with This may mean an initialization every 30 minutes or so Also if absolute positioning accuracy is needed as opposed to relative positioning a point of known coordinates should be used for initializing the system O f course more points in the area of the system use could be used provided that their coordinates are correctly entered into the system This can be easily implemented through development of a custom software application running on a PDA product Q How does the PowerMAX compare to competitor s products A The PowerMAX Is a unique solution in that it is very compact yet offers a high degree of performance There are anumber of DGPS products on the marketplace however very few of these are suitable for commercial use in applications such as Agricultural Guidance or GIS amp Mapping due to their positioning performance and their update rates The PowerMAX is up for this task and meets the needs for these applications The PowerMAX also offers the facility of outputting raw measurement data for post processing in the office Q What do do if I want to evaluate
46. es is not available or an external source Is preferential In addition to the conventional differential positioning with internal sources of corrections the PowerMAX also has a documented binary raw measurement protocol A RIN EX translator is available from CSI W ireless in the event that this may be useful in addition to some C code Snippets to aid in integrating the binary format itself into your own application For heading determination the PowerMAX uses a moving base station RTK solution This allows for avery precise computation of heading regardless of whether or not the receiver is in differential mode using either internal source of corrections or those from an external source Conventional Real Time Differential The majority of GPS navigation and positioning uses this form of positioning Conventional real time differential techniques are more robust in their usage and versatility than post processing or RTK solutions They are tolerant to errors in communication of the real time corrections PowerMAX User Manual 45 KI EE csi wireless from the base station or correction network provide a reasonable amount of accuracy Sub meter accuracy is best case and can be simply turned on and used without too much regard other than ensuring a lock to GPS satellite signals and the correction communication link How it Works Conventional DGPS involves setting up a reference GPS receiver at a point of known coordinates This rec
47. es tables that detail the default parameters of the PowerMAX as delivered Table 1 1 Default Applications W AAS SBAS Default e Dif if available Table 1 2 Default Port Settings Port Baud Rate Daa Bits Parity Stop Bt Interface Level Serial 9600 8 None 1 RS 232C Bluetooth Table 1 3 Default GPS NMEA Message Output Port GPS NMEA Messages Update Rate Serial GGA GSV VTG ZDA 1 Hz Bluetooth GGA GSV VTG ZDA 1 Hz PowerMAX User Manual 3 csi wireless Table 1 4 Default Parameters 1800 seconds KK 1 9 Pin Outs The following tables detail the pin out of the serial port of the PowerMAX Table 1 5 Serial Port Pin out RS 232C Interface Level Pin Signal 2 3 5 6 8 PowerMAX User Manual TXD serial RX D serial Sig Ground Power Ground Power Description N MEA 0183 binary and RTCM output N MEA 0183 binary and RTCM input Signal return Power Ground optional Power Input 9 5 to 32 VDC optional e fe csi wireless 2 Introduction This chapter provides a brief introduction to the PowerMAX and some of its high level features The remaining chapters provide more detailed information on the workings of the product As mentioned in the previous chapter if you are new to GPS and SBAS we recommend that you consult Appendix C for further information on these services and technology W hen powered for the first time the PowerMAX will perform a cold start which involves acquiring the av
48. es the SPS free of charge worldwide to all civilian users In order to maintain a strategic advantage the US DoD used to artificially degrade the performance of the SPS so that the positioning accuracy was limited to 100 meters 95 of the time This intentional degradation is called Selective Availability SA The effect of SA has been turned to zero since mid 2000 however it has not been officially turned off PowerMAX User Manual 44 csi wireless Currently autonomous GPS is able to provide accuracy on the order of 10 meters depending on the sophistication of the GPS engine For many positioning and navigation applications this level of accuracy is not sufficient and differential techniques must be employed Differential GPS The primary sources of errors that degrade GPS performance include SA currently set to a zero effect atmospheric errors timing errors satellite orbit errors and multipath Differential GPS DGPS Is essentially a differencing process that removes sources of error from the GPS position solution and improves the integrity of the GPS position solution There are anumber of methods of differential measurement correction e Conventional real time differential This is the most common form of correcting GPS errors in real time with corrections sent to the rover GPS receiver by some form of communications equipment Conventional real time differential uses C A code range measurements and their associated
49. f GPS signals at lower elevations can distort the measurements to satellites This error source is rather easily modeled within the GPS receiver and doesn t constitute a significant problem The error induced by the ionosphere is more significant however Is not as simple a task to correct The ionosphere is charged layer of the atmosphere responsible for the N orthern Lights Charged particles from the sun ionize this portion of the atmosphere resulting in an electrically active atmospheric layer This charged activity affects the GPS signals that penetrate this layer affecting the measured ranges The difficulty in removing the effect of the ionosphere is that it varies from day to day and even hour to hour due to the sun s 11 year solar cycle and the rotation of the earth respectively During the summer of 2001 the sun s solar cycle reached an 11 year high and going forward we will see a general cooling trend of the ionosphere over the next few years thus reducing ionospheric activity Removing the effect of the ionosphere depends on the architecture of the differential network DGPS radiobeacons for example use a more conventional approach that W AAS or SBAS in general DGPS beacons make use of a single reference station which provides real time GPS error corrections based upon measurements that it makes at its location It s possible that the state of the ionosphere differs between the remote user and the single reference station This
50. fact it s desirable to have afew degrees of latitude and longitude of ionospheric map coverage around your location to ensure that satellites available have these correctors Q How do I know if the PowerMAX module has acquired a SBAS signal PowerMAX User Manual 33 csi wireless A The PowerMAX allows you to request the output of the RD 1 message that contains the SBAS bit error rate BER for both receiver channels The BER value describes the rate of errors received from SBAS Ideally this should be zero however the PowerMAX should provide good performance up to a150 BER The PocketMAX utility discussed in the PocketMAX Manual is a useful tool that provides this information without needing to use N MEA commands Q How do know if the PowerMAX is offering a differentially corrected position A The PowerMAX outputs the GGA message as the main positioning data message This message contains a quality fix value that describes the GPS status If this value is a 2 then the position is differentially corrected The PocketMAX utility discussed in the PocketMAX Manual is a useful tool that provides this information without needing to use NMEA commands Q Does it matter much if the PowerMAX Is frequently losing lock on SBAS due to obstructions and the low satellite elevation angles at my geographic location A No provided that the receiver is receiving a full set of corrections relatively often Using the COAST technology t
51. fications O perational Specifications Item Specification Frequency Range Beacon 283 5 325 kHz LN A Gain Beacon 34 dB Frequency Range GPS 1 575 GHz LNA Gain GPS Various Available Power Specifications Item Specification PowerMAX User Manual 39 E E csi wireless Input voltage 4 9 to 13 VDC supplied by receiver Input current 50 60 mA Mechanical Characteristics Item Specification Enclosure PVC Plastic Length 128 mm 5 06 W idth 128 mm 5 06 Height 84 mm 3 33 W eight 450 g 1 0 Ib Mounting Thread 1 14 UNS2B Connector TNC S Extension C able RG 58 Environmental Specifications Item Specification Storage temperature 40 C to 80 C O peratingtemperature 30 C to 70 C Humidity 100 Condensing PowerMAX User Manual 40 csi wireless Appendix B Interface This appendix provides information on interfacing the main aspects of your PowerMAX The main purpose of the PowerMAX is to provide differentially corrected position and related information to a data logging or navigation device in the standard N MEA format In addition to the PowerMAX operating as a positioning sensor you may also have a use for the correction data received by the internal SBAS demodulator The following sections detail how to interface your PowerMAX depending on your application GPS NMEA Output W hen operating the PowerMAX as a differential positioning tool the data output from either PowerMAX communication port Serial or
52. formation on the W AAS service provided by the U S FAA gps faa go v Programs W AAS waas htm ESA EGNOS System Test Bed W eb Site This site contains information relating to past performance real time performance and broadcast schedule of EGNOS www esa int export esaEG estb htmi Solar and lonospheric Activity W eb Sites The following sites are useful in providing details regarding solar and ionospheric activity iono jpl nasa gov latest htm iono jpl nasa gov gim_dailymovie html PowerMAX User Manual 58 PowerMAX User Manual www spacew eather com http www n3kl org sun noaa htm csi wireless 59 Index GPGGA 23 GPGLL 24 GPGSA 24 GPGST 25 GPGSV 25 GPRMC 26 GPRRE 26 GPVTG 27 GPZDA 27 28 A Accuracy 47 49 Background Search beacon 8 Baud Rate 14 41 42 43 Beacon Receiver Performance 8 Beacon Receiver Signal to N oise Ratio SNR 8 Bit Error Rate W AAS 6 Bluetooth Connectivity 14 C C able Interface 2 11 C ables Power 13 Routing and Securing 11 CO AST Feature 8 Connectivity 13 41 42 43 Customer Service xii D Default NMEA Message O utput 3 15 Default Parameters 4 15 DGPS Errors 47 Age of Correction 48 Geometry 49 Latency 48 Multipath 49 Proximity 47 Differential Corrections 46 Differential GPS DGPS 46 PowerMAX User Manual EEE csi wireless G Global Search beacon 7 GPS 46 GPS Performan
53. ge Output The PowerMAX features two primary bi directional ports referred to as Serial and Bluetooth GPS data messages for both ports are easily configured by sending NMEA commands to the PowerMAX through either of its communication ports the output of the Serial Port can be configured through Bluetooth for instance and vice versa The JASC NMEA message discussed in detail in the Programming Manual allows you to turn messages on and off as you require 4 5 1 This Port and the Other Port The N MEA interface for the Serial Port and the Bluetooth Port use This and O ther terminology W hen interfacing to a port for the sake of turning data messages on or off on that same port the port is referred to as This port If you wish to turn a data message on or off on the opposite port to which you are communicating the opposite port is referred to as the O ther port For example if you are communicating with the PowerMAX Serial Port and wish to turn the GPGGA message on at an update rate of 5 Hz on the Bluetooth Port the following command would be used SIA SC GPGGA 5 0 THER lt CR gt lt LF gt If you wish to turn the GPGGA message on at 5 Hz on the Serial Port you would issue the following command SIA SC GPGGA 5 lt CR gt lt LF gt W hen turning a message on or off on This port you do not need to indicate This at the end of the message Consult the Programming Manual for more information on NMEA me
54. h For most consumer level applications a small amount of multipath is tolerable GPS Receiver Quality The quality of aGPS receiver has a dramatic influence on positioning accuracy Consumer based GPS products such as many affordable handheld and fixed mount receivers typically operate with an accuracy of 3 to 5 meters horizontally 95 of the time The accuracy of a particular product depends on the specific receiver s performance characteristics Higher accuracy GPS receivers are able to achieve sub 1 meter horizontal accuracy 95 of the time using real time DGPS transmissions The PowerMAX falls in to this latter category Space Based Augmentation Systems The US Federal Aviation Administration is in the process of developing a W ide Area Augmentation System W AAS for the purpose of providing accurate positioning to the aviation industry In addition to providing a high quality accurate service for this industry this service is available free of charge to all other civilian users and markets in North America This service falls into the greater category of Space Based Augmentation System SBAS Upon the successful completion of a 21 day test on August 24 2000 the FAA announced that W AAS would be running 24 hours per day seven days per week from then on Testing has shown since that this signal is accurate and reliable however since no official statement on It s Initial O perating C apability has been issued this signal is to used
55. he PowerMAX will be able to perform well for up to 40 minutes with old correction data similar to e Dif accuracy towards the end will not be as accurate as the beginning In order to obtain a full set of corrections the PowerMAX antenna receives the ionospheric map over a period of afew minutes This is the minimum amount of time required to get a full set of corrections for SBAS operation After this the receiver can CO AST until the next set of corrections have been received 6 7 Beacon Reception and Performance Q How do I know if I can receive a beacon signal in my area A Refer to Appendix B that contains approximate coverage maps for both beacon networks To ensure you have the most up to date information please contact your local Coast Guard authority who manages the service for the network details Q How do Know if the PowerMAX receiver has acquired a beacon signal A You can receive the signal strength SS and signal to noise ratio SN R from the internal beacon sensor by sending a request for the CSO message with the PC SI 1 lt C R gt lt LF gt command This information will tell you the quality of a lock Q How do I know if the PowerMAX is offering a differentially corrected position A The PowerMAX outputs the GGA message as the main positioning data message by default This message contains a quality fix value that describes the GPS status If this value is a 2 then the position is differentially corrected The P
56. he default value for JLIMIT is 10 meters Bluetooth LED blue This LED will remain off until a Bluetooth connection is established between the PowerMAX and the other device It will remain on until the connection is broken 38 csi wireless Appendix A Specifications This appendix provides the operational mechanical electrical physical and environmental specifications of the PowerMAX receiver Table A 1 PowerMAX Receiver Specifications Internal GPS Engine O perational Specifications Item Specification Frequency 1 575 GHz Channels 12 parallel tracking Horizontal accuracy lt 1m 95 Max Position update rate Upto5Hz Serial Interface Specifications standard cable Item Specification Serial port interface level RS 232C Data Port D B9 Socket Data Port available baud rates 4800 9600 19200 and 38400 Baud O utput protocol N MEA 0183 proprietary binary Input protocol N MEA 0183 External correction input protocol RICH SC 104 Power Specifications Item Specification Input voltage 9 5 to 32 VDC Power consumption lt 3 W Nominal Mechanical Characteristics Item Specification Enclosure Powder coated aluminum enclosure Length 160 mm 6 34 excluding connectors W idth 137 mm 5 44 H eight 63 mm 2 5 W eight 689 g 1 52 Ib Environmental Specifications Item Specification Storage temperature 40 C to 85 C O peratingtemperature 30 C to 70 C Humidity 95 N on C ondensing Table A 2 MGL 3 Antenna Speci
57. ing H yperT erminal that it is configured to use the correct PC communication port baud rate and that the local echo feature is on to see what you are typing 6 5 GPS Reception and Performance Q How do I know what the PowerMAX is doing A The PowerMAX supports standard N MEA data messages The GPGSV data message contains satellite tracking information Since the GPS automatically tracks GPS satellites when powered this will give you information on the tracking status If your receiver has computed a position this will be contained within the GPGGA data message Additionally the PowerMAX module has surface mounted status LEDs that give indication of receiver status Q Do I have to be careful when using the PowerMAX to ensure that it tracks properly A For best performance you have to be careful such that the hemisphere above the PowerMAX s antenna is unobstructed for satellite tracking The PowerMAX is tolerable of a certain amount of signal blockage due to the availability of redundant satellites only four are required for a position However as more Satellites are blocked the more impact this could have your positioning accuracy 6 6 SBAS Reception and Performance Q How do I know if I can receive a SBAS signal in my area A Refer to Appendix C that contains approximate coverage maps for both W AAS for North America and EGN OS for Europe It s important to have both signal coverage and ionospheric map coverage In
58. ion by logging raw measurement data at the base station and the rover simultaneously The differential processing can then be performed later in the office using sophisticated processing software tools There are a small variety of methodologies available to the operator such as static rapid static kinematic etc Describing in detail the various post processing techniques is beyond the scope of this document however generally post processing is more complicated from a procedural perspective and requires more skill to successfully operate than real time systems Factors Affecting DGPS Accuracy Many factors affect the positioning accuracy that a user may expect from a DGPS system The most significant of these influences include e Proximity of the remote user to the reference station atmospheric and orbit errors e Age of the received differential corrections e Atmospheric conditions at the beacon and remote user locations e Satellite constellation geometry often expressed as a Dilution of Precision DOP e Magnitude of GPS signal multipath present at the remote station e Quality of the GPS receiver being used at both the reference and remote stations Proximity of the Reference Station The distance between a remote user and the reference station can sometimes be considerable such as when using 300 kHz DGPS radiobeacons Consequently some of the errors associated with GPS at the base station differ somewhat from those at the remote
59. ite at www csi wireless com PowerMAX User Manual 57 csi wireless Appendix D Resources Reference Documents N ational Marine Electronics Association N ational Marine Electronics Association NMEA 0183 Standard for Interfacing Marine Electronic Devices Version 2 1 O ctober 15 NMEA 1995 PO Box 50040 Mobile Alabama 36605 USA Tel 1 205 473 1793 Fax 1 205 473 1669 Radio Technical Commission for Maritime Services RT CM Recommended Standards for Differential NAVSTAR GPS Service Version 2 2 Developed by Special Committee N o 104 RTCM 1998 1800 Diagonal Rd Suite 600 Alexandria VA 22314 2840 USA Tel 1 703 684 4481 Fax 1 703 836 4429 Radio Technical Commission for Aeronautics Minimum O perational Performance Standards MO PS for Global Positioning System W ide Area Augmentation System Airborne Equipment Document RTCA DO 229A Special Committee No 159 RTCA 1998 1828 L Street NW Suite 805 W ashington DC 20036 USA Tel 1 202 833 9339 ARIC Research Corporation Interface Control Document N avstar GPS Space Segment N avigation User Interfaces IC D GPS 200 April 12 2000 2250 E Imperial Highway Suite 450 EI Segundo CA 90245 3509 www navcen uscg go v gps geninfo default htm CSI Web Site This following address is the CSI W ireless W eb site which provides detailed information on all products offered by CSI W ireless WWwW Csi wireless com FAA WAAS W eb Site T his site offers general in
60. l correction source match by Issuing the appropriate JBAUD command e Issue a JDIFF T HIS lt C R gt lt LF gt command through the Serial port To establish communications between the PowerMAX and an external GPS receiver you must e Connect Pin 3 receive RX of the RTCM input port to transmit pin TX of the external correction source e Connect Pin 5 Common Ground of the RTC M input port to the signal return or common ground of the external correction source Note For successful communications the baud rate of the PowerMAX differential port must be set to match that of the external correction source The correction source must support an RS 232 interface level and the baud rates between each device must match PowerMAX DATA External Device Figure B 3 RTCM Data Input to Serial Port PowerMAX User Manual 43 d csi wireless Appendix C Introduction to GPS SBAS and Beacon This chapter provides a brief overview of GPS differential GPS Space Based Augmentation Systems SBA S such as W AAS EGNOS MSAS GAGAN and radiobeacon GPS The United States Department of D efense DoD operates a reliable 24 hour a day all weather Global Positioning System GPS N avstar the original name given to this geographic positioning and navigation tool includes a constellation of 24 satellites plus active spares orbiting the Earth at an altitude of approximately 22 000 km How it Works These satellites transmit coded
61. lgorithms that are able to anticipate how errors change during a period of correction loss Traditional receiver technology would experience an increasing degradation with increasing age of corrections resulting in less than adequate performance over a shorter period of time CO AST technology provides more consistent positioning during periods when signal loss occurs thus bridging the gap to when the signal is reacquired This means that the PowerMAX is more tolerant than competing products to loss of SBAS beacon or externally input RT CM SC 104 corrections PowerMAX User Manual 8 EEE csi wireless 2 6 Post Processing The PowerMAX receiver is able to output raw measurement data for post processing applications The raw measurement and ephemeris data are contained in the Bin 95 and 96 messages documented in the Programming Manud Both messages must be logged in a binary file W e make a DO S based RIN EX translator available however RIN EX has no facility to store station information Please contact CS W ireless Inc if you wish to use this utility 2 7 Evaluating Power MAX Performance As mentioned earlier CS W ireless evaluates performance of the PowerMAX receiver with the objective of determining best case performance in a real world environment O ur static testing has shown that the PowerMAX achieves a performance better than one meter 95 of the time The qualifier of 95 is a statistical probability O ften you may see man
62. lt CR gt lt LF gt command e Turn RTCM on using the JRTCM 1 lt CR gt lt LF gt command To establish communications between the PowerMAX and an external GPS receiver you must e Connect Pin 2 transmit TX of the serial port to the receive pin RX of the separate GPS receiver or logging device e Connect Pin 5 Common Ground of the serial port to the signal return or common ground of the separate GPS receiver Figure B 2 illustrates the required interface between the PowerMAX and device that receives position information PowerMAX DATA External D evice 2TX RICM RX vom UD Figure B 2 RTCM Data Output From Serial Port Note For successful communications the baud rate of the Power MAX Serial port must be set to match that of the separate GPS receiver Additionally you must interface the Power MAX to an RS 232C serial port of the separate GPS receiver Refer to the Programming Manual for instructions related to setting the PowerMAX baud rate External Correction Input In this operating mode an external correction device inputs RTCM correction data through the Serial port In order to accomplish this the PowerMAX must be commanded to use external corrections using the JD IFF command To configure external correction input on the Serial port you must PowerMAX User Manual 42 6 6 csi wireless e Communicate with the PowerMAX on the Serial Port Ensure that the baud rate of the Serial Port and the externa
63. lts Keeping in mind that this horizontal performance specification is a real world but ideal scenario test obstruction of satellites multipath signals from reflective objects and operating with poor corrections will detract from the receiver s ability to provide accurate reliable positions Differential performance can also be compromised if the PowerMAX is used in aregion without sufficient ionospheric map coverage If external corrections are used the baseline separation between the remote and base station antennas can affect performance Since the PowerMAX will be used in the real world blockage of the line of sight to SBAS satellites is often inevitable In this case beacon may be used instead O ur COAST technology provides solace from obstruction of SBAS or beacon services for up to 30 to 40 minutes depending on the amount of tolerable performance drift Section 2 5 discusses CO AST technology in further detail PowerMAX User Manual 5 Se csi wireless The estimated positioning precision is accessible through the use of our PocketMAX utility discussed in the PocketMAX Manual and N MEA 0183 commandresponses as described in C hapter 6 The GST NMEA data message As the receiver is not able to determine accuracy with respect to a known location in real time this is traditionally performed in post mission analysis the precision numbers are relative in nature and are approximates 2 1 3 Update Rates The update rate of each N M
64. lue is worse than the current threshold the green DGPS LED will blink indicating that differential mode has been attained but that the residual has not yet met the threshold zs Blue Bluetooth indicator this LED will illuminate when there is a bluetooth connection between the PowerMAX and a Bluetooth compatible device and off when there is no bluetooth connection Once power is applied to the PowerMAX the power LED will illuminate solidly and the GPS LED will blink a few times followed by a lamp test O nce the GPS lock LED has finished blinking a few times you will see the GPS lock Differential lock and the DGPS position LEDs illuminate in sequence a few times and then go out W hen the PowerMAX acquires a GPS lock the yellow GPS lock LED will illuminate solidly Similarly the differential LED will illuminate when the SBAS demodulator or beacon module has acquired lock or externally input corrections are being successfully received The green DGPS position LED will illuminate when the receiver has acquired a GPS lock differential lock and has applied corrections within the position solution The above table provides more detail on LED status The following image displays the front panel layout of the PowerMAX receiver including the location and labeling of each LED For more information on LED operation and troubleshooting refer to Chapter 8 Figure 3 3 PowerMAX Front Panel PowerMAX User Manual 16 csi wireless 4 Oper
65. m operation but also with GPS and DGPS The chapters that follow provide detailed information on the PowerMAX receiver including the hardware and software interface in addition to various descriptions of technologies and features that it supports Some notable features of the PowerMAX receiver follow e 12 channel GPS engine 2 channels dedicated to SBAS tracking e Sub meter horizontal accuracy 95 e Raw measurement output via documented binary messages e Position and raw measurement update rates of 5 Hz max e COAST technology provides consistent performance with old correction data e e Dif ready A base station free way of differentially positioning e W AAS EGN OS and beacon differential sources e Quick times to first fix J O ne full duplex serial port can be used to configure the product or to output or receive RTC M corrections e One Bluetooth module for virtual serial port communication e 1 PPS timing output e 3 W power consumption Organization This manual contains the following chapters Chapter 1 Quick Start provides information to help you get your system running quickly Chapter 2 Introduction introduces you to the PowerMAX and some of its main features Chapter 3 Features provides details on the fundamental operating modes of the PowerMAX receiver and its associated default parameters Chapter 4 O peration Basics describes how to configure and operate the PowerMAX receiver PowerMAX User Manu
66. mation from the PowerMAX You may configure a selection of NMEA 0183 data messages on one port at various update rates each message has a maximum update rate and a different selection of NMEA 0183 messages with different rates on the other port Chapter 6 presents information relating to the N MEA interface of the PowerMAX Appendix D Resources provides contact information should you wish to purchase a copy of the N MEA 0183 standard 4 2 2 Binary Interface Binary messages may be output from the PowerMAX simultaneously as NMEA 0183 data Binary messages have a proprietary definition and would likely require custom software support if you wish to use them Binary messages are inherently more efficient than NMEA 0183 and would be used when you require maximum communication efficiency Use of binary messages for most users is not recommended the N MEA interface allows you to control the operation of the PowerMAX and also receive most types of information regarding status and positioning information Note If you wish to log binary data please ensure that your logging software has opened the file as a binary file otherwise you may lose data 4 2 3 RTCM SC 104 Protocol RTCM SC 104 is a standard that defines the data structure for differential correction information for a variety of differential correction applications It has been developed by the Radio Technical Commission for Maritime services RTC M and has become an industry standard fo
67. methods of providing a truth reference may need to be provided through observation times on surveyed monuments or traversing well known routes If you require assistance in developing atest setup or procedure for evaluating the PowerMAX please contact C SI W ireless PowerMAX User Manual 10 e fe Se csi wireless 3 Features This chapter describes the main features of the PowerMAX system The PowerMAX system is composed primarily of the following parts e A PowerMAX receiver e An MGL 3 antenna e Associated cables This chapter provides details on the fundamental operating modes of the PowerMAX receiver and its associated default parameters 3 1 System Parts List The following list of standard equipment is included with the PowerMAX system One PowerMax Receiver P N 803 0030 01A One MGL 3 Antenna P N 804 3003 05A One Magnetic Mount P N 725 0007 014 One 3 Meter Power Cable P N 054 0009 000 One 3 Meter Data Cable P N 050 0011 022 One 5 Meter Antenna Cable P N 052 0005 000 One Manual CD P N 132 0127 000 containing the PowerMAX Reference Manual 3 2 Cable Interface The PowerMAX receiver requires power and antenna cable interfaces The data cable is optional if you intend to use the wireless bluetooth interface The following figure shows the various connections located on the rear panel of the PowerMAX enclosure Figure 3 1 Cable Interface 3 2 1 Routing and Securing the Cable W hen choosing aroute
68. n as the sky wave Depending on its reflectance the sky wave may bounce off the ionosphere and back to Earth causing reception of the ground wave to fade Fading occurs when the ground and sky waves interfere with each other The effect of fading is that reception may fade in and out However this problem usually occurs in the evening when the ionosphere becomes more reflective and usually on the edge of coverage areas Fading is not usually an issue with overlapping coverage areas of beacons and their large overall range Atmospheric attenuation plays a minor part in signal transmission range as it absorbs and scatters the signal This type of loss is the least significant of those described Radiobeacon Reception Various sources of noise affect beacon reception and include Engine noise Alternator noise N oise from Power lines DC to AC inverting equipment Electric devices such as CRT s electric motors and solenoids N oise generated by this type of equipment can mask the beacon signal reducing or impairing reception Radiobeacon C overage The Figure below shows the approximate radiobeacon coverage throughout the world In this figure light shaded regions note current coverage with beacon stations symbolized as white circles PowerMAX User Manual 56 csi wireless Figure C 7 World DGPS Radiobeacon C overage The world beacon networks continue to expand For more current coverage consult the CSI W ireless W eb s
69. obeacon DGPS Many Marine authorities such as Coast Guards have installed networks of radiobeacons that broadcast DGPS corrections to users of this system W ith the increasing utility of these networks for terrestrial applications there is an increasing trend towards densification of these networks inland 2 4 Beacon Operation The following sections describe the general operation and performance monitoring of the beacon engine within the PowerMAX 2 4 1 Tune Modes The PowerMAX may be operated in either Automatic or Manual Beacon tune modes In Automatic Beacon Search ABS mode the receiver will identify and tune to the station providing the strongest DGPS signal In Manual Tune mode you specify the frequency to which the receiver will tune or select the desired beacon by name from the built in global listing 2 4 1 1 Automatic Beacon Search ABS Mode W hen operating using the internal beacon sensor as the source of DGPS correction information the PowerMAX operates in Automatic Beacon Search ABS mode by default selecting and tuning to the most appropriate beacon without operator intervention The PowerMAX s internal beacon receiver uses its two independent beacon channels to identify and lock to DGPS beacons without interrupting the continuous flow of RTCM data to the GPS receiver ABS mode is ideal for navigation applications over considerable areas eliminating the need for operator intervention when transitioning from one beac
70. ocketMAX utility discussed in the PocketMAX Manual is a useful tool that provides this information without needing to use NMEA commands Q Does it matter much if the PowerMAX is frequently losing lock on beacon signals due to a noisy environment or weak signals A No provided that the receiver is receiving a full set of corrections relatively often Using the COAST technology the PowerMAX will be able to perform well for up to 30 to 40 minutes PowerMAX User Manual 34 csi wireless with old correction data depending on the degree of tolerable drift In order to obtain a full set of corrections the beacon receiver needs to be locked for a few seconds for a 200 bps station depending on the number of satellite corrections be transmitted For a100 bps modulation rate it could take up to six or more seconds depending on the number of satellite corrections being sent After this the receiver can coast until the next set of corrections has been received if there is further data loss 6 8 e Dif Q Why was e Dif developed A Once Selective Availability was removed in May of 2000 it opened the door for CSI W ireless to develop this technology as environmental errors change much more slowly than SA did The purpose of e Dif was to market an alternative to users in replace of costly subscription based differential services around the world where free services such as DGPS beacon and SBAS did not exist Q Will e Dif perform as w
71. on coverage zone to another 2 4 1 2 ABS Global Beacon Search W hen powered for the first time in ABS mode the PowerMAX initiates a Global Search examining each available DGPS beacon frequency and recording Signal Strength SS measurements in units of dBuV m to the Global Search Table The receiver uses these measured values to compute an average SS and noise floor to sort the frequencies in descending order of SS The beacon receiver s two channels cooperatively examine the frequencies with the highest SS measurements above the computed noise floor to determine the station providing the strongest RTCM signal The receiver s primary channel locks to the first identified DGPS broadcast while the second channel continues searching in the background for superior beacon signals If no signal is available the PowerMAX will initiate a fresh Global Search continuing this cycle until it finds a valid station PowerMAX User Manual 7 SE csi wireless 2 4 1 3 ABS Background Beacon Search During the Background Search the second beacon channel examines all frequencies at both 100 and 200 bps MSK bit rates to identify beacons possessing superior signal quality Ifa DGPS broadcast is identified that exhibits a 2 dB greater signal strength than that of the primary station the receiver will automatically switch to this beacon No loss of lock occurs on the primary station during the background scan The PowerMAX stores the current primary bea
72. on required to access GPS Like GPS DGPS data and broadcast standards exist to ensure compatibility between DGPS services and associated hardware and software The Radio Technical Commission for Maritime Services Special Committee 104 has developed the primary DGPS standard associated with conventional DGPS designated RTC M SC 104 V2 2 This correction standard is used by many correction services including many private reference stations and DGPS beacon systems The PowerMAX supports this correction protocol via either of its two serial ports In addition to the RTCM standard the Radio Technical Commission for Aeronautics has a differential service intended for wide area correction services designated RTCM SC 159 The United States Federal Aviation Administration s W ide Area Augmentation System W AAS and other compatible Space Based Augmentation Systems SBAS such as the European Geostationary N avigation O verlay System EGN O S and the Japanese MT SAT Satellite based Augmentation System MSAS use this data format The PowerMAX receiver is compatible with each of these differential services Note When using a differential correction service the resultant position may be referenced to a local datum rather than the W GS 84 ellipsoid Please refer to your signal provider for more information PowerMAX User Manual 46 ll emmmer csi wireless Post Processing Post processing is amethod to compute accurate positions in post miss
73. onnected If the PowerMAX is connected to acustom or special device ensure that the serial connection to it does not have any incompatible signal lines present that may not allow either to communicate properly Try using the Serial port for communication as only pins 2 3 and 5 which are the only pins required for communication are connected Make sure that the baud rate of the PowerMAX matches the other device The other device must also support an 8 data bit 1 stop bit and no parity port configuration 8 N 1 Some devices support different settings that may be user configurable Ensure that the settings match Consult the troubleshooting section of the other devices reference manual to determine if there may be a problem with that equipment Q Am I able to configure the two serial ports with different baud rates A Yes the ports are independent For instance you may have one port set to 4800 and the other to 19200 or vice versa Q Am I able to have the PowerMAX output different NMEA messages through the two ports A Yes you may have different N MEA messages turned on for the two serial ports Further these N MEA messages may also be at different update rates Q How can I determine the current configuration of the PowerMAX A The JSHO W lt CR gt lt LF gt command will request the configuration information from the PowerMAX The response will be similar to the following output and is described in detail in the
74. ons provide information that may help you to isolate and solve the problem that you are experiencing Q What do I do if I can t resolve the problem after trying to diagnose it myself A You should contact your dealer to see if they have any information that may help to solve the problem They may be able to provide some in person assistance too If this either isn t viable or does not solve the problem CSI W ireless Technical Support is available during normal business hours to help solve the problem You may reach Technical Support at Telephone number 1 403 259 3311 Fax number 1 403 259 8866 E mail address techsupport csi wireless com Technical Support is available from 8 00 AM to 5 00 PM Mountain Time Monday to Friday PowerMAX User Manual 31 csi wireless 6 4 Power Communication and Configuration Q My PowerMAX system doesn t appear to be communicating what do I do A This could be one of a few Issues L 2 Examine the PowerMAX cables and connectors for signs of damage Ensure that you are properly powering the system with the correct voltage Since you re required to terminate the power input with your choice of connector ensure that you have made a good connection to the power supply Check the documentation of the receiving device if not a PC computer to ensure that the transmit line from the PowerMAX is connected to the receive line of the other device Also ensure that the signal grounds are c
75. owerMAX to be used successfully in regions that competitive products may not For W AAS this Is especially important in Canada for regions north of approximately 54 N latitude and east of 110 W longitude Extrapolation also provides enhanced coverage throughout much of the Gulf of Mexico Please note that the process of estimating ionospheric corrections beyond the W AAS broadcast PowerMAX User Manual 53 csi wireless map would not be as good as having an extended W AAS map in the first place This difference may lead to minor accuracy degradation Figures C 3 and C 4 depict the broadcast W AAS ionospheric map extent and the CSI W ireless extrapolated version respectively As can be seen from Figure C 3 the coverage compared to Figure C 1 extends further in all directions enhancing usable coverage Similar to the W AAS ionospheric map extrapolation Figures C 5 and C 6 depict the broadcast EGNOS ionospheric map extent and the CSI W ireless extrapolated version respectively As can be seen from Figure C 6 the coverage compared to Figure C 5 extends further in all directions enhancing usable coverage oc EWEN fiat i a i i ee EL EE EFE LN RWWWRRANAI BEE i ER EEE EE LE EET TT TT ham PRE LLL LR 3 Figure C 4 Extrapolated WAAS lonospheric Correction Map PowerMAX User Manual 54 Figure C 6 Extrapolated EGNOS lonospheric Correction Map Radiobeacon DGPS Radiobeacon Range The bro
76. ple if a satellite is South of your current location at alow elevation angle the pierce point of the ionosphere will be considerably South of your location since the ionosphere is at an altitude of approximately 60 km There must be sufficient ionospheric map coverage beyond your location in order to have ionospheric correctors for all satellites To enhance the information provided by SBAS the PowerMAX extrapolates the ionospheric information beyond the broadcast information This increases the usable geography for W AAS and is discussed in Section 1 5 5 This feature helps to improve the usable coverage area of a SBAS service PowerMAX User Manual 50 Simmer csi wireless S a Signal Information A SBAS transmits correction data on the same frequency as GPS from a geostationary satellite the space segment allowing the use of the same receiver equipment used for GPS Another advantage of having SBAS transmit on the same frequency is that only one antenna is required Reception Since SBAS broadcast in the L band the signal requires a line of sight in the same manner as GPS to maintain signal acquisition Currently two commercial marine communication satellites are transmitting W AAS data for public use and one each is located above both the Pacific O cean and Northern Brazil Due to their location these satellites may appear lower on the horizon depending on your geographic position on land In regions where the satellites
77. r communication of correction information RTC M is a binary data protocol and is not readable via a terminal program It appears as garbage data on screen since it is a binary format and not ASCII text The following is an example of how the RTCM data appears on screen mRMPEPJfeUtNsmMFM NVt IOTDbA xXGh kDH FadW yaLRryrDuhcBNVQA N ozbSDQO L nr GakeTlpLLrYpDgASrLRrON zW uWQH z aGxWYEtAI FxW qgagLRryrDCikANQCJF DE E w_mlroMNjJkKOsmMFM PWOWW HVEbA xGhLJQH FW aNsmMFM WVLANQGS amzQAilIu Pqx _IZhTCpLLrYpdP kOsmMFM kVDHwVGbA P WWuNt_SW_yMsmMnqdrhcC sE Z C vJImNGAHJVhATCgLRryrdviStW H_GbA P wxu K RTCM has various levels of detail however the highest level is the message RTCM defines numerous messages that contain specific information The PowerMAX receiver processes the C A code and does not support more advanced methods of differential positioning such as real time kinematic RTK that uses different RTCM message types Considering this fact only certain RTCM messages are important for use with the PowerMAX e Type 1 and Type 9 messages both of which contain similar information These two messages contain pseudorange corrections and range rate corrections to each GPS satellite e The Type 2 message contains delta differential corrections that are used when the remote receiver is using a different satellite navigation message than used by the base station e The Type 5 message contains GPS constellation health information used fo
78. r improving tracking performance of a GPS receiver PowerMAX User Manual 18 csi wireless e The Type 6 message contains null information and is broadcast so that a beacon receiver demodulating the data from the broadcast does not lose lock when the beacon station has no new data to transmit Note RTCM isa local area data standard This means that when positioning with external correction input to the PowerMAX from an external source or outputting corrections from the PowerMAX to another GPS receiver performance will degrade as a function of distance from the base station The additional degradation will depend on the difference in observed orbit and ionospheric errors between the reference station and the remote unit A general rule of thumb would be an additional 1 m error per 100 miles This error is often seen as a bias in positioning resulting in a position offset The scatter of the receiver is likely to remain close to constant The RTCM SC 104 data output by the PowerMAX is converted from the RTCA SC 159 data broadcast by SBAS networks Appendix D Resources contains the contact information should you wish to purchase a copy of the RTCM SC 104 specification 4 3 Configuring PowerMAX All aspects of PowerMAX operation may be configured through the serial port with the use of N MEA 0183 commands or using the PocketMAX utility discussed in the PocketMAX manual These commands are described in the Programming Manual The follo
79. rections in seconds Reference station identification Checksum Carriage return and line feed PowerMAX User Manual 23 csi wireless 5 2 2 GLL Data Message The GLL message contains Latitude and Longitude In the table below the GLL data message Is broken down into its components This message has the following format GPGLL ddmm mmmm s dddmm mmmm s hhmmss ss s cc lt C R gt lt LF gt Table 5 4 GLL Data Message Defined Field Description ddmm mmmmm Latitude in degrees minutes and decimal minutes S s N or s S for North or South latitude dddmm mmmmm Longitude in degrees minutes and decimal minutes S s E or s W for East or W est longitude hhmmss ss UTC time in hours minutes and seconds of GPS position S Status s A valid s V invalid TCC Checksum lt CR gt lt LF gt Carriage return and line feed 5 2 3 GSA Data Message The GSA message contains GPS DOP and active satellite information Only satellites used in the position computation are present in this message N ull fields are present when data is unavailable due to the number of satellites tracked The table below breaks down the GSA message into its components This message has the following format G PG SA a b cc dd ee ff gg hh iL KkK mm nn 00 p p 0 0 r r cc lt C R gt lt LF gt Table 5 5 GSA Data Message Defined Field Description a b cc to 00 p p q q gy SES lt CR gt lt LF gt PowerMAX User Manual Satellite acquisition mode M
80. roduct warranty 3 7 Serial Port Interface There is one serial port on the PowerMAX and it is compatible with the RS 232C interface level to communicate with external data loggers navigation systems PC computers PDAs and other devices This serial port is accessible via the rear panel of the PowerMAX enclosure and has a Data label You can interface most devices to the PowerMAX directly with a serial cable accommodating any gender changes necessary or with the addition of a null modem as necessary The serial port should be used for firmware updates The following table provides the pin assignments for the serial port PowerMAX User Manual 13 csi wireless Table 3 2 Serial Port Pin out RS 232C Interface Level Pin Signal Description 2 TXD N MEA 0183 binary and RTCM output for the MAIN port 3 RX D N MEA 0183 binary and RTCM input for the MAIN port 5 Sig Ground Signal return 6 Power Ground Power Ground optional 8 Power Power Input 9 5 to 32 VDC optional Figure 3 2 displays the numbering scheme for extension cable s D B9 socket connectors female The associated numbering for the plug connector male is a mirror reflection of scheme showed in this figure 94321 9870 Figure 3 2 DB9 Socket Numbering Refer to Appendix B for further interfacing information Note For successful communications the baud rate of the PowerMAX serial ports must be set to match that of the devices to which they are connected
81. so this LED should go on solid yellow to indicate that GPS has lock This is true even if differential corrections are not available If the LED is continually blinking and you have been programming your PowerMAX it is possible it is still in programming mode The PowerMAX will not communicate while in this state Simply power cycle the PowerMAX to restore normal communications Differential LED Yellow LED closest to Green This LED can be in several states Off Differential signal has not been received Flickering on and off the receiver is close to acquiring the differential signal Blinking at a steady rate Differential signal has been acquired but the Bit Error Rate BER of the best signal tracked is higher than 150 Generally this will not affect performance but it is a warning of weak signal strendh On Solid W AAS or beacon signal has been acquired and signal strength is good DGPS LED green This LED will remain off until a differentially corrected GPS solution is available It will blink at a steady rate if the solution has not converged to the accuracy specified by the JLIMIT command and will become solid green after the solution has converged The JLIMIT sets the threshold for the RMS residual error and this error gives a rough indication of expected user accuracy N ote however that it is not a direct measure of accuracy Factors such as constellation geometry must also be taken into account T
82. ss please have the product model and serial number available when contacting CSI W ireless Customer Service In the event that your equipment requires service we recommend that you contact your dealer directly However if this is not possible you must contact C SI W ireless Customer Service to obtain a Return Merchandise Authorization RMA number before returning any product to CSI W ireless If you are returning a product for repair you must also provide a fault description before C SI W ireless will issue an RMA number W hen providing the RMA number CSI W ireless will provide you with shipping instructions to assist you in returning the equipment PowerMAX User Manual xii csi wireless W orld W ide W eb Site CSI W ireless maintains a W orld W ide W eb home page at the following address WwWw csi wireless com A corporate profile product information application news GPS and DGPS literature beacon coverage information and software are available at this site Document Conventions Bold is used to emphasize certain points Notes Cautions and Warnings N otes Cautions and W arnings stress important information regarding the installation configuration and operation of the PowerMAX receiver Note Notes outline important information of a general nature Cautions Cautions inform of possible sources of difficulty or situations that may cause damage to the product W arning W arnings inform of situations that
83. ssages 4 6 Saving PowerMAX Configuration Each time that you change the configuration of the PowerMAX you may wish to save the new configuration so the receiver does not have to be reconfigured again for the next power cycle The save the settings issue the JSA VE command and the receiver will record the current configuration to non volatile memory The PowerMAX will let you know when the save process has been completed which can take approximately five seconds 4 7 Using the Serial Port for RTCM Input The PowerMAX Serial port can be used to accommodate externally supplied corrections input according to the RTC M SC 104 protocol To use the Serial port of the PowerMAX for correction input you must set the PowerMAX to operate in other differential mode using the following command while connected to the Serial port JDIFF THIS lt C R gt lt LF gt Although the following RTCM SC 104 message types don t all contain differential data the PowerMAX is compatible with them PowerMAX User Manual 20 S csi wireless e Type I e Type 2 e Type 3 e Type 5 e Type 6 e Type 7 e Type 9 e Type 16 To return to using SBAS as the correction source send the following command to the PowerMAX SJDIFF W AAS lt C R gt lt LF gt To return to using beacon as the correction source send the following command to the PowerMAX SJDIFF BEA C ON lt CR gt lt LF gt You will find detailed information on NMEA messages supported by
84. ssessssessusesessssessuseseusscnuseseseusevenuseusegevavaevensusevsueveusevassuueveusesavsevessuansensssanssaes 41 Figure B 2 RTCM Data O utput From Serial e 42 Figure B 3 RTCM Data Input to Serial Port EE 43 ENN 52 Figure C 2 EGNOS Re 53 Figure C 3 Broadcast W AAS Inonspheric Correction Map 54 Figure CA Extrapolated W AAS Inonspheric Correction Map NENNEN 54 Figure C 5 Broadcast EGN O S Inonspheric Correction Map 55 Figure C 6 Extrapolated EGNOS Inonspheric Correction Map 55 Figure C 7 W orld DGPS Radio beacon C OVEr aGe ccsecsssssssssssssssssssscsssssssssscsssesauscsesesessesesesavsceesesaseceesesavscsesesavensesesas 57 PowerMAX User Manual viii Ta Ve csi wireless List ofTables NNN NNN 3 Table 1 2 Default Port Settings E 3 Table 1 3 Default GPS NMEA Message Output 3 Table 1 4 Default Parameters EE 4 Table 1 5 Serial Port Pin out RS 232C Interface Level ENNEN 4 Table 2 1 Beacon Receiver Performance SNR Reading 8 Table 2 2 Horizontal Accuracy Probability Statietce NENNEN 9 Table 2 3 Horizontal Accuracy Statistic Conversione NENNEN 9 Table NTNU Ar 12 Table 3 2 Serial Port Pin out RS 232C Interface Level ENEE 14 Table 3 3 ME NAN 15 Table 3 4 Default Port SAP regeert ege eegener 15 Table 3 5 Default GPS NMEA Message Output 15 Table 3 6 D grauit yee S srsrisiniiniirons nare ETN NENE E E E E 15 Table 3 7 PN 16 Table 5 1 N MEA Message Elements E 22 ev 23 Table 5 3 GGA Data Message Defined E 23 Table 5
85. stions 6 1 General Q Are the SBAS services reliable for differential operation A Yes these services have proven themselves for some time now and have shown excellent results As both W AAS and EGN O S are in test mode currently they are not to be used as a sole means of navigation Additionally as they are under test there may be perio ds of outage or times when the signal should not be used W e recommend that you refer to Appendix D Resources of this manual for W eb sites that provide details regarding the broadcast schedule of W AAS and EGNOS Q Canthe COAST technology work with corrections from an external source A Yes the PowerMAX will operate in a similar fashion with the CO AST technology as when using SBAS However SBAS corrections have the advantage that they are separated into separate error components allowing the PowerMAX to anticipate how errors will change over the coasting period with more consistent accuracy and for alonger period than regular RTCM range corrections Q Is e Dif the solution for my positioning needs A It is difficult to say without knowing more about your application e Dif is not a different solution replacement for everyone s application Certain ap plications lend themselves to successful e D if operation such as crop dusting In this application the aircraft must refuel and be filled with chemicals quite frequently perhaps every 20 minutes This allows for anew initialization wh
86. the PowerMAX in Chapter 6 NMEA 0183 Messages PowerMAX User Manual 21 csi wireless 5 NMEA 0183 Messages The PowerMAX GPS module supports a selection of NMEA 0183 and proprietary binary messages This chapter identifies the selection of standard and proprietary NMEA 0183 messages for the PowerMAX receiver 5 1 NMEA Message Elements N MEA 0183 messages have acommon structure consisting of a message header data fields checksum and carriage return line feed message terminator An example N MEA sentence follows X X YYY 772 222 222 XX lt C R gt lt LF gt The components of this generic NMEA message example are displayed in T able 6 1 Table 5 1 NMEA Message Elements Element Description Message header character X X N MEA Talker field GP indicates a GPS talker YYY Type of GPS NMEA Message ZZZ Variable Length Message Fields XX Checksum lt CR gt Carriage Return lt LF gt Line Feed Null or empty fields occur when no information Is available for that field PowerMAX User Manual 22 5 2 Data Messages csi wireless The following subsections describe the N MEA data messages listed in the T able below in detail Table 5 2 Data Messages Message Max Rate Description GPGGA 5 Hz Global Positioning System Fix D ata GPGLL 5 HZ Geographic Position Latitude Longitude GPGSA 1Hz GN SS Global N avigation Satellite System DO P and Active Satellites GPGST 1 Hz GN SS Pseudorange Error Statistics GPGSV 1 Hz GN
87. the RTC M input port matches the baud rate of the external source No data from PowerMAX RTCM mode e Verify the pin out between the RTC M source and the RTC N input port transmit from the source must go to receive of the RTC M input port and grounds must be connected Refer to Appendix B N on differential GPS output e Verify PowerMAX SBAS and lock status or external source is locked 7 2 Using the LEDs to Troubleshoot The PowerMAX receiver has 5 LED indicator lights that serve as status indicators The first 4 lights should all be illuminated solid non blinking when the receiver is powered on and has a valid GPS and differential solution The last LED furthest to the right should only be illuminated solid if you are connected using Bluetooth communications O therwise the lights can be in various states blinking on solid or off Table 8 2 describes the LED light operation PowerMAX User Manual 37 Table 7 2 LED Functions PowerMAX User Manual a EE csi wireless Power LED red This LED should be on solid once power is applied to the receiver This is the only LED that is not under computer control GPS LED Yellow LED closest to Red This LED serves two purposes At power on it will blink 3 to 4 times once per second and then go off If it fails to blink the Differential processor is likely to have failed If it does not stop blinking the GPS processor is the likely culprit After a minute or
88. tween your packing slip and the contents of your shipment please contact the sales person with which you placed your order immediately 1 3 Cable Connections The connections required by the PowerMAX are very straightforward All cables necessary for complete operation are provided The PowerMAX needs to be connected to a power supply 9 5 to 32 VDC and to the MGL 3 combination GPS and beacon antenna The power connector on the PowerMAX is a miniature 2 pin circular locking connector and the RF connector isa TNC socket The power connector is labeled Power and the GPS RF input connector is labeled Antenna There is no power switch to turn on the PowerMAX Once the proper voltage input is applied to the connector the system will start up There is another option for powering the PowerMAX It is possible to power it through the serial port labeled D ata instead of through the power connector The PowerMAX is specially set up to receive power on pin 8 and power ground on pin 6 Refer to Table 1 5 for the serial port pin out PowerMAX User Manual 1 Ze SE csi wireless To communicate with the PowerMAX you have two options one D BY socket connector is available on the back panel labeled D ata giving access to the RS 232 serial port of the PowerMAX The other option is Bluetooth communication which is wireless using a Bluetooth enabled PDA with a Bluetooth compatible software such as C Ss PocketMAX If you have a PDA or
89. uate one receiver against another statically they should be using identical correction input from an external source and also share the same antenna using a power splitter equipped with appropriate DC blocking of the receivers and a bias T to externally power the antenna W ith this type of setup the errors in the system are identical with the exception of receiver noise Although this is a comparison of the GPS performance quality of a receiver it excludes other performance merits of a GPS engine The dynamic ability of a receiver should be compared in a similar way with the test subjects sharing the same antenna Unless a receiver is moving its software filters are not stressed in a similar manner to the final product application W hen testing dynamically a much more accurate reference would need to be used such as an RTK system so that a truth position per epoch is available Further there are other performance merits of aGPS engine such as its ability to maintain a lock on GPS and SBAS satellites In this case the same GPS antenna should be shared between the receiver test subjects For the sake of comparing the tracking availability of one receiver to another no accurate truth system is required unless performance testing is also to be analyzed Again an RTK system would be required however it s questionable how its performance will fair with environments where there are numerous obstructions such as foliage O ther
90. ufacturers using a probability of rms or standard deviation Performance measures with these probabilities are not directly comparable to a 95 measure since they are a lower probability less than 70 probability This means that less often a product would position within a radius of the prescribed amount The following table summarizes the common horizontal statistical probabilities Table 2 2 Horizontal Accuracy Probability Statistics rt Rms root mean square 63 to 68 CEP circular error probability 50 2drms twice the distance root mean square 95 to 98 R95 95 radius 95 It is possible to convert from one statistic to another using the following table Using the value where the From row meets the To column multiply the accuracy by this conversion value Table 2 3 Horizontal Accuracy Statistic Conversions For example if Product A after test results in an accuracy of 90 cm 95 R95 and you want to compare this to Product B that has a sub meter horizontal rms specification select the value from where the R95 row and the rms column intersect to convert to rms PowerMAX User Manual 9 D Ve csi wireless You will see that this conversion value is 0 59 Multiply the 90 cm accuracy by this conversion factor and the result will be 53 cm rms If you now compare this to Product B s specification of sub meter rms you can see the first Product A would offer better performance To properly eval
91. w it Works A SBAS incorporates a modular architecture similar to GPS comprised of aGround Segment Space Segment and User Segment e The Ground Segment includes reference stations processing centers a communication network and N avigation Land Earth Stations N ELS e The Space Segment includes geostationary satellites For example W AAS and EGNOS use Inmarsat lIll transponders e The user segment consists of the user equipment such as a PowerMAX receiver and antenna A SBAS uses a state based approach in their software architecture This means that a separate correction Is made available for each error source rather than the sum effect of errors on the user equipment s range measurements This more effectively manages the issue of spatial decorrelation than some other techniques resulting in a more consistent system performance regardless of geographic location with respect to reference stations Specifically SBAS calculates separate errors for the following e The ionospheric error e GPS satellite timing errors e GPS satellite orbit errors Provided that a GPS satellite is available to the SBAS reference station network for tracking purposes orbit and timing error corrections will be available for that satellite lonospheric corrections for that satellite are only available if the signal passes through the ionospheric map provided by SBAS for example the W AAS ionospheric map covers the majority of N orth America As an exam
92. wing items are user configurable e Selecting one of the three on board applications SBAS Beacon or e Dif if present e Setting the baud rate of both communication ports e Choosing which NMEA data messages to output on the dual serial ports and the update rate of each message e Setting the maximum differential age cut off e Setting the satellite elevation angle cut off mask 4 4 Firmware The software that runs the PowerMAX is often referred to as firmware since it operates at a low level There are two types of firmware within the PowerMAX for the on board digital signal processor DSP and the ARM processor Each of these types of firmware may be upgraded in the field through the main serial port as new revisions become available The ARM processor of the PowerMAX engine supports two simultaneous versions of firmware O nly one of them is in operation at any given time These two versions of firmware may have different functionality and are also referred to as applications The PowerMAX currently ships with a SBAS W AAS application and the e Dif application The Programming Manual describes the JAPP command used to change between the two PowerMAX applications W ithin the W AAS application there are two differential modes being W AAS and beacon The Programming Manual describes the JD IFF command used to change between the two differential modes PowerMAX User Manual 19 e fe mmm csi wireless 4 5 Configuring Data Messa
93. wnload the Programming Manual from the CSI W ireless website PowerMAX User Manual 2 e fe EEE csi wireless 1 6 Binary Message Interface In addition to the N MEA interface the PowerMAX also supports a selection of binary messages There is a wider array of information available through the binary messages plus binary messages are inherently more efficient with data If your application has a requirement for raw measurement data for instance this information is available only in a binary format Consult the Programming Manual for more information on Binary messages 1 7 PocketMAX PocketMAX is a free utility that C SI W ireless has developed to assist you with controlling and monitoring your PowerMAX receiver It requires a device that runs a W indows PocketPC 2000 2002 or 2003 operating system The PocketMAX Manual provides detailed information on how to interact through both serial and bluetooth communications between your PowerMAX receiver and your PDA based PocketMAX utility This program allows you to graphically monitor the status and function of the PowerMAX in addition to providing an interface for its control The PocketMAX Manual is available for download from the CSI W ireless website W e recommend that you gain your initial experience with the PowerMAX using this utility and then if you wish migrate your work to adumb terminal 1 8 Default Parameters Although presented in the following chapters this section provid
94. workmanship for a period of 12 months from delivery to such end purchaser Repairs and replacement components are warranted subject to the exclusions and procedures set forth below to be free under normal use and maintenance from defects in material and workmanship for 90 days from performance or delivery or for the balance of the original warranty period whichever is greater Purchaser s Exclusive Remedy The end purchaser s exclusive remedy under this warranty shall be limited to the repair or replacement at the option of CSI W ireless of any defective Products or components thereof The end user shall notify CSI W ireless or a CSI W ireless approved service center immediately of any claimed defect Repairs shall be made through a CSI W ireless approved service center only Exclusions CSI W ireless does not warrant damage occurring in transit or due to misuse abuse improper installation neglect lightning or other electrical discharge or fresh salt water immersion of Products Repair modification or service of CSI W ireless Products by any party other than a CSI W ireless approved service center shall render this warranty null and void CSI W ireless does not warrant claims asserted after the end of the warranty period CSI W ireless does not warrant or guarantee the precision or accuracy of positions obtained when using Products Products are not intended for primary navigation or for use in safety of life applications The potenti
95. y y Track made good referenced to true north ddmmyy UTC date of position fix in day month year d d Magnetic Variation in degrees V Variation sense v E East v W W est CC Checksum lt C R gt lt LF gt Carriage return and line feed 5 2 RRE Data Message The RRE message contains the satellite range residuals and estimated position error The table below breaks down the RRE data message into its components This message has the following format S GPRRE n iL rr irr nhh h vvv v cc lt C R gt lt LF gt Table 5 9 RRE Data Message Defined Field Description n ii rr N umber of satellites used in position computation Satellite number Range residual in meters hhh h Horizontal position error estimate in meters VW V Vertical position error estimate in meters TCC Checksum lt CR gt lt LF gt Carriage return and line feed PowerMAX User Manual 26 csi wireless 5 28 VTG Data Message The VTG message contains velocity and course information The table below breaks down the VTG data message into its components This message has the following format SGPVTG jttt c ttt c 999 99 u 999 90 utcc lt C R gt lt LF gt Table 5 10 VTG Data Message Defined Field Description ttt True course over ground ttt 000 to 359 in degrees C True course over ground indicator c T always ttt Magnetic course over ground ttt 000 to 359 in degrees output with magnetic model option only C Magnetic course over ground Indicator

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