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1. Modular Cannister Propulsion 1 2 HP electric motor nickel cadmium battery silver zinc option Supervisory Control Command Telemetry Frequency diverse FSK Acoustic link Depth Control Manual or Automatic Heading Control Manual or Automatic Autonomous Control Microprocessor Control for Auto Heading and Depth and on board logic Navigation Compass Sperry CL ll gyroscope Depth Pressure Sensor with digital readout at consol feet or meters Echo Sounder Mesotech or to Customer specification Obstacle Avoidance Amatek Straza 511 or customer RTP TENT specification Positioning e e Track positioning Oceano Long Baselir system to customer specification Track maintenance Amatek Straza modified MRQ doppler sonar or to customer specification Capabilities Controllable to a range of 5 mm Positioning to an accuracy of 5 mete Capable of maintaining parallel tracks 25 meters apart Options wera cael be e Se Meal n Side Scan Sonar Acoustic Television and lighting Gyro Stabilization MATERIAL Es COMPOMENTE FOR ONE UMET CT CEN ss W lt dus Cms L ll T LU BSS TREC DART DEPLOYMENT SYSTEM SPECIFICATION PRI
2. Investigation of Methods Currently Employed to Obtain ice Thickness Distributions R Hudson Beaufort Sea Ice Motion Programmes OERD 67113 67114 Institute of Ocean Sciences Sidney B C 018295 kasa This work was supported by the Federal Panel on Energy R amp D PERD Department of Supply and Services Canada DSS File O6SB FP941 3 2205 INVESTIGATION OF METHODS CURRENTLY EMPLOYED TO OBTAIN ICE THICKNESS DISTRIBUTIONS For Dr David Topham Department of Fisheries and Oceans Patricia Bay Sidney 8 C By Polar Tech Ltd 676 Wain Road RR1 Sidney 604 656 9131 Attn Rick Hudson February 1984 POLAR TECH LTO Under Ice Profiling 1 SUMMARY Current techniques to profile ice thicknesses a single ice pressure ridge and a ridged field are investigated For the former a combination of side looking sonar profiles ground truth holes provide a cost effective method of producing bottomside contour maps As an added refinement a diver might be used to evaluate the roughness of the ridge s surface in a subjective manner To profile a larger ridged floe a combination of stereoscopic aerial photography above and submarine sonar scanning below is recommended The ARCS untethered unmanned vehicle looks promising Keel depths and tidge orientations could be mapped effectively but the technology is new and the hidden costs still undefined Direct methods of measuri
3. 482 19 in rack mount TFT Modei 971 3 Sonar Display Screen Size 330 mm 13 in diagonal Signal RGB from Model 971 2 Input 3 x BNC 75 a or high Z loop through Raster 525 lines interlaced 15 750 Hz or 625 lines interlaced 15 625 Hz Temperature Operating 5 C to 40 C Storage 20 C to 60 C Power 120 240 V 60 50 Hz 2 1 Dimensions 374 mm 14 7 in wide x 351 mm 13 8 in high x 409 mm 16 1 deep Weight 18 kg 40 Ib Ordering Information Model 971 1 Sonar Head Model 971 2 Sonar Processor Model 971 3 Sonar Display Standard Accessories for 971 1 Glenair GL20G 4S D dummy fitted Glenair GL20G 4S F3 underwater connector with 1m 3ft tail Glenair GL20G 402 locking sleeve 971 2 Power Cable MS to 05 3 pin or tail Signal Cable MS to tail Output Cables 3 x BNC male to BNC male 1 O Cable MS to D type 971 3 Power Cable System Operator s manual Service Manual MESOTECH SYSTEMS LTD 2830 Huntington PL Port Coquitlam B C Canada V3C 4T3 Telephone 604 464 8144 Telex 04 353637 APPENDIX II Submarine specifications ARCS Autonomous Remote Controlled Submersible PRINCIPAL CHARACTERISTICS Dimensions Overall diameter 25 Length 14 16 feet Displacement 2150 2450 lbs Endurance I MP 20 hours SD ed x9 99 a 5 knots Maximum Operating Depth 1200 feet 3000 feet optional Construction
4. Sea Compare remote sensing methods SLR laser profilometer stereo photos utilising keel ridge correlations to direct through ice sensing methods POLAR TECH LTD Under Ice Profiling 4 2 SURVEY SINGLE RIDGE To profile single pressure ridge detail technique suggests itself as having all the requirements necessary Conventional expertise has centred around the use of side looking sonars to obtain moderately accurate profiles of keels Such unit together with recently developed signal processing permits contour maps 3 D charts to be produced in near real time But the system cannot stand alone Drill holes are necessary to ground truth the sonar data In addition there is for this application considerable interest in the surface texture of the keels This can only be recorded by direct observation TV cameras are a very inferior substitute However it is the author s experience that de briefing with divers as to what was seen underwater can also be misleading Often two divers will describe the same feature in quite different terms The solution therefore reduces to a compromise depending on permissible cost and logistics It is recommended that the program 1 Use a narrow beam side looking sonar to achieve contour maps of the ridge s shape Effective beam range is 50m with a vertical resolution dependent on uater depth shallou uater introduces multiple echo paths generally tim or bet
5. available with operators for rent Costs vary from 1800 to 3000 d depending on add on equipment SITDART is bigger version of the DART weighing 600 lb and offering a superior survey platform HYDRA HISUB and HYDROSTAR are all larger vessels which would require large logistical back up in the field Offshore Survey s SEAL is a much cheaper unit but has no axial stability so could not be used to sound upwards All of the above are tethered via an umbilical line Ranges vary based on power available to pull a longer line j Positioning is via two or more hydrophones lowered through the ice to establish an acoustic reference grid Positioning accuracy is t1m horizontal The submarine would carry a pressure gauge to determine its true depth enabling the ice s profile to be measured 50cm or better Cost to operate the unit to survey a single standard floe would result in some mobilization testing time likely 10 000 plus freight 3000 plus S61 support at 4000 for 1 day plus operating costs of 6000 plus demobilization processing of data at 3000 Total 26 000 The Bedford Institute of Oceanography has commissioned ISE to build a long torpedo like submersible to operate untethered under ice called ARCS This is scheduled for sea trials in mid March 1984 and permits extensive surveys 5 n m x 5 to be carried out from a single entry point POLAR TECH LTD Under Ice Profiling 1 vehicle uses 4 h
6. in the sonar reading Mesotech Ltd of Vancouver produce sonar systems which operate the Arctic Their Model 971 has a range of 100m and operates at 675 kHz Cost is about 50 000 They do not rent Offshore Survey Ltd of Vancouver have done a number of bottom side profiles They oun and operate an Edo Uestern system uhich has small diameter for fast surveys and Mesotech 952 sonar 360 kHz 1 5 beamwidth requiring a 12 inch diameter hole They have also developed software for their Hewlett Packard 9826 computer which converts the raw radial data and writes it to an XY plotter to display either as a contour map cross sectional chart or 3 0 profile Effective range is about 50m with horizontal and vertical resolutions of approximately 50 Assuming typical ridge of about 150m length 3 holes on either side would suffice to profile the length This could achieved in a working day An advantage of this system is that data plots are produced in near real time allowing changes in research direction Cost for such a project is 1 operator at 375 d 2 hole drillers at 350 d plus helicopter at 1000 hr Sub total 4 000 This cost includes the near final plots of the floe Mobilization from Vancouver will likely add 10 000 to this in freight air fares and preparation of field equipment but would be spread over the cost of the large ice field survey as uell POLAR TECH LTD Under Ice Profilin
7. multiyear ice floe having a typical diameter of 700m poses a different problem from that of the single ridge Here the emphasis is on statistical evaluation to establish the bottom roughness in general terms Major ridge orientations and keel depth distributions supercede the high resolution requirement and a variety of less precise more cost effective systems are proposed These are summarised as follows 1 Aerial photography is the most often used technique and permits good stereoscopic resolution to be achieved at reasonable cost However there is a limited data base allowing the correlation between sail height and keel depth a ridge this results error which may be very significant More work needs to be done before this technique may be used alone 2 Underice survey using an unmanned submersible To date only one attempt has been made to use a tethered device to profile under ice Its results confidential but rumoured to be poor The current decline in offshore work has resulted in a leaser s market as regards subs but all are still untried The new ARCS built for the Bedford Institute N S by ISE of Vancouver is due for trials in mid March It untethered device specifically designed for under ice work and may prove to be a very powerful bottom side ice profiler 3 Laser profilometers have been used widely to establish ridge height distributions but are unsuitable statistically for a sm
8. 5 230 V 60 Hz 130 840 mm wide x 610 mm deep x 380 mm high 33 x24 x15 248 mm x 298 mm x 1005 mm long 9 75 x11 75 x59 6 increase length to 1520 mm 52 2 46 kg qe lbs 32 kg 70 lbs 40 kg 88 lbs 26 kg 57 lbs For 230 V operation of sonar specify at time of order Specifications subject to change without notice MESOTECH SYSTEMS LTD 2830 Huntington PI Port Coquitlam 8 C Canada VIC 413 MESOTECH MODEL 952 BOTTOM SCAN PROFILING SONAR RECORDER CASE MESOTECH SYSTEMS LTD 2830 Huntington PI Port Coquitlam Canada 3 473 Teiechone 604 464 8144 Telex 04 353637 MESOTEGH MODEL 952 DUAL AXIS BOTTOM SCAN PROFILING SONAR The Dual Axis version of the 952 Profiling Sonar is similar in operation to the Single Axis version However under processor control using the integrated Bearing Drive the Sonar Head can be oriented to new bearing The Transducer Bearing can be manually selected by operating the appropriate controls or processor selected according to 2 programmable bearing step angle The Dual Axis Model is capable of recording up to 8 separate profiles The stored records can be plotted separately in an isometric format or in hydrographic chart format enabling a contour map to be drawn The Dual Axis Sonar can plot these records on an HP 9872 X Y Plotter on a CRT Monitor or electrosensitive graphics plotter to be interfaced with the monitor
9. 8144 Telex 04 353837 MODEL 952 BOTTOM SCAN PROFILING SONAR METHOD OF OPERATION NARROW BEAM TRANSOUCER IS SWEPT THROUGH A VERTICAL PLANE ALONG A LINE OF BEARING N BOTTOM PROFILE FIGURE BOTTOM PROFILE ALONG THIS LINE IS RECORDED ON THE X Y PLOTTER FIGURE 2 T PROFILE NO e PROFILES ARE RECOROED 4 ALONG SEVERAL LINES TNT OF BEARING TO MEASURE I BOTTOM CONTOURS E EE IAEA 8 MESOTECH SYSTEMS LTD 2830 Huntington Pl Zn me Port Coquitlam 8 C Canada v3C 473 Telephone 604 464 8144 Telex 04 353637 FIGURE 3 MESOTECH SPECIFICATIONS MODEL 952 OPERATING FREQUENCY BEAM WIDTH RANGE SCALES MINIMUM RANGE RANGE RESOLUTION RANGE ACCURACY SWEEP ANGLES From Vertical SWEEP OFFSETS 2 Axis only ANGLE RESOLUTION BEARING ANGLE 2 Axis only SWEEP TIMES Minimum Maximum SERIAL INTERFACE POWER REQUIREMENTS Sonar Plotter SIZES Recorder Case 1 Axis Sonar Head in Frame 2 Axis Sonar Head in Frame WEIGHT Recorder Case full 1 Axis Sonar Head in Frame 2 Axis Sonar Head in Frame Head Proc Cable 30 m 100 ft 360 kHz 1257 20 40 80 160 m 1 5 m 50 09 m 0 5 22 5 45 67 52 90 609 509 0 30 60 0 75 90 selected in 17 steps 2 5 22 5 20 m 44 s 90 160 m 20 mA Current Loop 9600 Baud Full Duplex 115 230 V 60 Hz 500 VA 11
10. 9825 Calculator HP 9872C 8 pen X Y Plotter 280x430 mm 11x17 inch paper NOTE Plotter supplies obtainable from Hewlett Packard CRT Monitor for 952 Model 1800 Driver Monitor 230 mm 9 inch CRT 110 220V 50 Hz 625 lines or 60 Hz 525 lines 75 NOTE 2 Customers may supply their own standard Video Display Monitor Specifications subject to change without notice MESOTECH SYSTEMS LTD 2830 Huntington Port Coquitlam 8 C Canada 3 473 Teiepnone 604 464 8144 Telex 04 353637 Ormnorc survey 77227 ACOUSTIC PROFILING SERVICES Mesotech modei 952 bottom profiling sonar Inverted use of profiter for mapping underside of sea ice through hole Sonar operation over stern of barge for monitoring of dredging progress FEATURES e Mapping of seafloor from stationary point e Seabed profiling from small hole in the ice ridge keel and multi year ice floe profiling e Continuous monitoring of dredging progress from dredging platform Well suited for pipe trench inspections showing sition of pipe in trench e deal search tool for locating glory holes or wellheads e Contour map generation from sonar data Contour map generated from under ice profiles pisi bes acoustic profiling system has been ted for a wide variety of applications by SHORE SURVEY Se monitoring Positioning of drillships over wellheads and glory holes e Search and locat
11. NCIPAL CHARACTERISTICS Drum Dimensions 42 flange x 30 barrel x 34 wide Drum Capacity 1 560 ft of 1 diameter cable with l of free flange above the top layer 2 000 155 at 0 to 126 fpm 2 510 lbs at 0 to 100 fpm Drive The winch is driven by means of a Vickers vane type motor through a totally enclosed inline planetary gear reducer that will be located inside the drum barrel at one end of the winch Drum Ratings Full Drum Bare Drum Brake n Ausco totally enclosed spring set pressure released disc type brake will be located between the hydraulic motor and planetary gear reducer This brake will be automatically applied whenever the winch control is in the neutral position Minimum holding capacity of the brake is 3 000 155 at the full drum Frame amp Drum Fabricated aluminum Base The winch and crane package will be mounted on a fabricated steel base suitable for bolting to the deck of a vessel Slip Rings Provision will be made in one end of the winch drum for the mounting of your slip ring assembly Provision is also made in the drum barrel for the termination of your cable and the entry of the wires to connect to the slip ring assembly Crane The winch and power package will be mounted on a Viva Model No 510 hydraulically actuated crane This crane will be modified for use in a marine atmosphere by having the cylinder rods and pivot pins manufactured from stainless ste
12. all survey of this kind scanning laser is still at ne discussion stage and may not be operational for another years 4 SLAR and SAR are both unsuited for the single floe experiment although some work suggests that SAR may be used to determine ridge width and hence depth A joint topside bottomside survey is suggested to correlate the sail keel ratio for the particular ice zone of interest The relationship between sail height and keel depth is poorly documented Wadhams 1975 Wadhams 4 Horne 1977 and 1980 Hoare et al 1980a 4 b and may be used to determine keels on a statistical basis only It is not possible to determine individual ridge profiles with any degree of confidence The probability distribution of ridges obtained from laser data in POLAR TECH LTD Under Ice Profiling 9 the Beaufort Sea is given as a function of ridge height Wadhams 1975 as P h dh 7 727 exp 1 603 h dh P h dh is defined as the probability of encountering a ridge of height betueen h and h dh per kilometer of the transect The probability distribution of keels obtained in the near zone of the Beaufort Sea using an upuard looking sonar mounted on the sea bed rather than a submarine uas calculated Hoare al 1980 as N D dO 2089 exp 0 408 0 dD N D 40 is the number of keels of draft between D and D dO over the entire season If the ridge distribution function is normalised to unity at h 0 and the keel distr
13. be very diver dependent POLAR TECH LTD Under Ice Profiling 7 2 3 LOCAL AERIAL SURVEY A light weight and relatively cheap alternative to the above would be to suspend a camera at sufficient height above the ground that stereoscopic photographs could be taken but without the problems associated with aircraft Given reasonably little wind meteorological balloon filled by bottle could carry aloft a Hasselblad camera or equivalent If ground field of 300m uas required a height of much the same is all that is required The balloon could be controlled by lines from 3 fishing rods Photographs would be taken using a radio controlled trigger which is commercially available The cost of materials is small and a 2 25 square inch negative would permit adequate vertical resolution on the ground especially as the pictures uould carry reference points set up by the field party It might be argued that the technique is redundant since if there is a helicopter on site it may well be used for the photographs And if the large field survey is being done over the same period there will in all probability be a 9 inch square camera being used Both are true Houever the technique is small light and easily deployed and may prove superior to the problems associated with getting an aircraft rated for photographic work and setting it up POLAR TECH LTQ Under Ice Profiling 8 3 SURVEY LARGE ICE FIELD The survey of a
14. d It does not lend itself to small scale surveys however since its footprint is very small Many passes would be needed to Obtain sufficient statistical data to profile the ice floe of interest while the difficulties of flying a precise line accurate to a few metres would be impossible The technique is included for completeness and to draw attention to the interest currently being shown by a number of Federal agencies CCRS EMR Dept Surveys DoD in the construction of a scanning laser DSS funded contract to build such a device for the Hydrographic Survey has about a year to run before delivery of the system however it is possible that a smaller lower powered system using similar processing software and related hardware could be used as the basis for another unit capable of profiling solid surfaces from the air Contact person is Jack Gibson at CCRS POLAR TECH LTD Under Ice Profiling 14 3 4 SLAR SAR Neither SLAR nor SAR have the resolution required for the current study although the SAR imagery would be useful spacially for detail at the scale of interest SAR can only resolve ridge widths paper by Inkster amp Loury 1980 claims that by measuring the width the ridge height deduced a thesis which requires further work 3 5 DIRECT SENSING METHODS There are currently three different techniques being used to determine the thickness of sea ice from its topside in a direct manner These are Electr
15. el The crane will be as shown in the enclosed Viva pamphlet and will be complete with one hydraulic extension and no manual extensions TREC DART DEPLOYMENT SYSTEM SPECIFICATION Continued Spooling Power Unit The winch drum will be complete with an automatic spooling mechanism This will consist of two vertical stainless steel rollers that are mounted in a fabricated aluminum carriage The rollers are supported on sealed ball bearings and are mounted on stainless steel shafts The carriage is supported on a stainless steel guide bar and is driven directly from the drum by means of a diamond screw a hardened steel shuttle and a stainless steel roller chain reduction A clutch handwheel is located at one end of the diamond screw When this is disengaged the carriage may be moved manually to suit the position of the wire on the drum The carriage is also equipped with a horizontal roller to support the cable when it is in the slack condition The winch and crane are powered by a 20 H P electro hydraulic pumping unit that will be mounted so that it rotates with the crane and winch assembly The electric motor to drive the pumps will be mounted top of a fabricated aluminum reservoir that will be complete with all necessary inlet and outlet ports a filler breather cap and a sight level gauge Power requirements for the electric motor will be 220 440 volt 3 phase 60 cycle The motor will have an explosion pr
16. entred on the cursor is magnified x4 linear Data Input RS 232 C for user labels date time to be written on screen Data Output RS 232 C status amp errors Temperature Operating 5 C to 40 C Storage 20 C to 60 C Power Supply 120 240 V 60 50 Hz 2 1 A Dimensions 483 mm 19 in wide x 178 mm 7 in high x 432 mm 17 in deep Weight 14 kg 31 Ib A Colour imaging Sonar System A Model 971 System comprises one each Model 971 1 Sonar Head Model 971 2 Sonar Pro cessor and Model 971 3 Sonar Display The Sonar Head is an O ring sealed pressure proof aluminum cylinder with a transmit receive trans ducer at one end and a power control data con nector at the other end Inside are telementry micro processor transmitter receiver motor and power circuits The Sonar Processor is a welded aluminum box black and anodised with white lettering it controis all data aquisition modes processes the telemetered data and outputs 525 line NTSC or 625 line PAL RGB video The Sonar Display is a very high resolution monitor with direct input to the Red Green and Blue electron guns of the CRT hence RGB With an appropriate adaptor NTSC or PAL signals may be stored on a video recorder SONAR Very high resolution monitor Direct RGB input 1 4 million pixel display Model 971 2 Sonar Processor 22mm 406 mm 16 in i j i x td A cabine gt lt
17. g 6 2 2 DIVER SURVEY Candive in Vancouver are the acknowledged experts in this field and have carried out numerous under ice surveys The survey would be done using a single diver plus 1 2 technical support assuming visual inspection duties only Depths in excess of 20m make for long decompression times Deep keels may have to be estimated subjectively rather than lose valuable time Diver would be in a in dry suit with an air hose to the surface Party would likely muster out af Tuk so no transport fees A number of spot depths could be recorded during a dive to cross check the sonar data Vertical accuracy would be 25cm Horizontal correlation is rather diver dependent The technique s advantage is that a substantially better evaluation of the ice s structure can be obtained from the observations of the divers Diving costs are Supervisor 460 d diver 420 d support equipment 250 d For a 1 day survey mobilising out of Tuk excluding helicopter likely cost is 1 130 If the survey were carried out exclusively by divers rows and columns of stakes would be used to pinpoint a 10m x 10m grid the underside of the ice A diver would then hold a pressure sensitive depth gauge at each stake and record the position and reading by voice phone with the surface above As mentioned earlier this technique is considerably slower than the sonar method Vertical resolution would be less than 25cm Horizontal error would
18. ibution is normalised to unity at D 0 thereby reducing the effects due to the differences measuring instruments and their time space relationship the distributions become P h dh s exp 1 803 h dh N D dD exp 0 408 D dO The ratio of the exponential coefficients represents the calculated keel sail ratio which is 3 93 This is in agreement with many of the field observations based on the field profiling of a feu ridges at a time but represents the only knoun value based on a large statistical sample Hoare et al 13805 POLAR TECH LTD Under Ice Profiling 10 23 1 AERIAL SURVEY Uidely used and very quick slow flying aircraft is needed to carry out the precision survey otherwise the plane s velocity will degrade the photographic negative at low altitude only charter aircraft operating in the north out of Inuvik which has an FAA approved camera hatch is a Rockwell Commander which cruises at over 200 knots and may not be suitable for low level precision reconnaisance Cost 800 hr Okanagan Helicopters have a camera mount for a Bell 208 uhich may be more effective for small surveys Stereoscopic processing of a typical floe using a 10m grid would be under 2000 This would include a 10 metre grid from which contours could be drawn plus spot heights of any features of interest Accuracy is dependent on there being a sea level reference to deduce zero plus another known high point to remove til
19. ion of subsea wellheads Protiling shape and depth of pipe trenches e Position determination of pipe in pipe trench Positioning of subsea completion manifold for hook up to wellheads e Contour mapping of seabed along pipe corridor Contour mapping of underside of sea ice Mapping and profiling of ice scours on seabed Monitoring progress of man made islands and berms Delineation of grounded sea ice boundaries Several cable and pipe mounted deployment systems have been developed to allow downward horizontal and upward looking operations Data recording and processing capabilities provide a wide choice of visual presentations o on either CRT displays or X Y plotters Ten sequential under ice profiles with horizontal spacing of ten degrees Offshore Survey and Positioning Services Ltd Offshore Survey inc 1974 Spicer Road North Vancouver B C Canada V7H 2 Seattle Washington Telephone 604 929 7961 Telex 04 352838 U S A in Canada by Mediacolor Colour Imaging Sonar Model 971 Light weight miniature head Fits any vehicle or rig Mounts any orientation Model 971 1 Sonar Head Frequency 675 kHz Beamwidth 1 7 horizontal 60 vertical Mechanical Resolution 0 225 step angle Scanning 360 continuous or locked Power Supply 22 26 Vdc at 1 A max Connector Glenair GL 30G 4 pin Cable 4000 m 13000 ft max length Construction Alumi
20. le in late 1984 POLAR TECH LTO Under Ice Profiling 15 4 REFERENCES Hoare R D Danielewicz B W Pilkington G R O Rourke J C wards R D An upward looking sonar system to profile ice keels for one year Proc OCEANS 80 Seattle Sept 1980 a p123 Hoare R D Danielewicz B W Pilington G R O Rourke J C Seasonal pack ice characteristics in the shear zone of the Beaufort Sea based on data from an upward looking sonic profiler APOA Project 147 January 1980 b Uadhams P Sea ice ridge statistics Technical Report 36 of the Beaufort Sea Project 1975 Wadhams P Lowry R T A joint topside bottomside remote sensing experiment on Arctic sea ice Proc 4th Canadian Symp on Remote Sensing Quebec City May 1977 Wadhams P Lowry R T An analysis of ice profiles obtained by submarine sonar the Beaufort Sea Jnl Glac v25 93 p401 1980 POLAR TECH LTD Under Ice Profiling 16 APPENDIX I Sonar profiling specifications x MODEL 952 PRECISION PROFILING SONAR THE DREDGEMASTERS SONAR MESOTECH SYSTEMS LTD MESOTEGH MODEL 952 SINGLE AXIS BOTTOM SCAN PROFILING SONAR The Mesotech Model 952 Bottom Scan Profiling Sonar is a system which from a single location records a profile of water depths along particular line of bearing By manually changing the orientation of the device profiles along several lines of bearing can be obtained to provide detailed informatio
21. n of bottom contours The Model 952 is particularly useful in harbour and canal bathymetry and during dredging operations The ability to gather bottom profile information from a single point greatly speeds surveys and drastically reduces the amount of navigation required during a survey The Model 952 Sonar Head transmits a narrow beam high frequency acoustic pulse The narrow beam is swept through a verticle plane and the time for each pulse return is recorded allowing calculation of the slant range to the bottom The bottom profile is calculated from the slant range and angle data The complete system consists of the Sonar Head which is mounted underwater and the Recorder Case They are connected by 2 100 foot cable The Sonar Head contains the acoustic transducer the stepping motor which sweeps the transducer inclinometer which senses rolling the sonar transmitter and sonar receiver The Recorder Case contains a microprocessor control system which reads the panel switches drives the transducer stepping motor controls the sonar transmitter and receiver reads the inclino meter stores the data and records the data on an X Y plotter The Model 952 can also operate as precision recording depth sounder when the transducer is locked in the straight down position Specifications subject to change without notice MESOTECH SYSTEMS LTO 2830 Huntington Pt Port Coquiliam 8 C Canada 3 413 Telephone 604 464
22. ng ice thickness are briefly reviewed there is little suitable for ridge profiling POLAR TECH LTD Under Ice Profiling 2 INDEX SUMMA a A N CA v E P rad 1 2 4 Project OS FLL ooh bo osa SURVEY OF A SINGLE RIDGE SA ROS CAR 2 1 Through ice 2 2 Diver SUEVEY 6 20402604 rennen 2 3 Local aerial on SURVEY OF A LARGE ICE 9 3 4 survey rv xA ORI TI 2 Submarine 1 3 Scanning E RS ar ki U SEARS SA Reacts an exami NTSA S Direct sensing methods 42499422 15 REFERENCES HRS a 41 6 Appendix I Sonar specifications Appendix II Submarine specifications POLAR TECH LTO Under Ice Profiling 3 1 PROJECT DEFINITION Investigate and compare methods currently employed to obtain ice thickness distributions for the following situations 1 detailed under ice survey of single isolated ridge Compare a diver performed precision under ice survey with side scan sonar techniques give their expected accuracies with respect to vertical and horizontal positioning Compare the above with any other practical techniques that have been used 2 Under ice topography of field of ice keels Review available results af keel ridge height statistics in the Beaufort
23. num alloy 6061 6 300 Series stainless steel rigid PVC polyacetal epoxy Finish Hard anodise red Temperature Operating 10 C to 40 C Storage 50 C to 50 C Depth 1000 m 3300 ft max working Dimensions 89 mm 3 5 in diameter 372 mm 14 64 in long Weight air 3 6 kg 8 lb In water 1 4 kg 3 lb Model 971 1 Sonar Head Transducer rotates 360 continuously oris set to 30 increments 372 14 64 in 43mm Mounting 4 Holes 1 69 in 10 32 UNF x 13 mm 0 5 in deep 89 mm 3 5 in Note Specifications subject to change without notice Compact processor controller Comprehensive modes Simple logical controis Model 971 2 Sonar Processor Display Modes Sector Polar Perspective Side scan Linear and Test Ranges 0 5 10 20 50 100 m Scanning Arcs 360 continuous or 30 60 120 sector Sector Centre 0 30 60 90 120 150 180 210 240 270 300 330 Scanning Speed Slow 1 shot per step Medium 1 shot per 2 steps Fast 1 shot per 4 steps Side Scan Transducer may be locked at any of the above sector centres Data Resolution 512 x 512 x 128 levels colours Timing Resolution 16 us 12mm 0 5 in Video Output RGB with composite sync on channels Analogue IV p p into 75 Cursor Control Moveable to any point on display Readout Range and Bearing to cursor are displayed on screen Zoom Area c
24. o magnetic induction method Peter Hoogensen af Geo Physicon n algary as or a number of years used a modified shallow seismic investigation device It is essentially two magnetic di poles mounted 3 metres apart on a horizontal boom which is carried in the field without difficulty The read out of the ice s thickness based on induction paths is not direct and is subject to a consistant error which may be corrected However the system integrates over the length of the boom and is also susceptable to water enclosures in the ice It is therefore not suitable for defining ridge bottomside profiles Pulse radar GSSI and more recently MPB have developed pulsed radar systems usually in the 100 MHz band to determine ice thickness Like the magnetic di pole system it is sensitive to water layers but if the antenna is mounted close to the ice it measures a fairly small bottom surface However the equipment is expensive to rent heavy and heavily operator dependent For these reasons it is not considered suitable for ridge studies Acoustic resonance method This technique is currently being developed by a Sidney company and holds promise as a small cheap alternative which measure ice thicknesses from 0 2m to 20m it too is sensitive to water layering if they are large and may therefore give poor results in firstyear ridges Multiyear should not be a problem prototype is currently being tested and may be availab
25. oof enclosure The pump to power the winch will be an Eaton axial piston type variable displacement over center pump This will be connected in a closed loop circuit with hydraulic motor at the winch This pump will be controlled by a set of Honeywell controls that will give infinitely variable speed control of the winch in either direction of operation and will have a central neutral position The pump for the crane will be a Vickers constant displacement vane type pump that will be connected in an open loop circuit with the crane controls Controls for the crane will consist of a 4 bank hydraulic valve package that will give Separate control of each the crane functions All necessary components to complete both hydraulic systems are included and will be mounted and prepiped to provide a complete unit
26. or electrosensitive plotter A Model 1800 CRT Printer Driver is required In the continuous sweep mode the CRI constantly displays the new profile when a search is being conducted Specifications subject to change without notice MESOTECH SYSTEMS LTD 2830 Huntington Port Coquittam Canada V3C 473 Telephone 604 464 8144 T amp lex 04 353637 MESOTECH MIST 734 x 6100 mm 2 875 20 800M 3050 254 76 mm 0 10 3 MESOTECH MODEL 952 GENERAL ARRANGEMENT MESOTECH SYSTEMS LTD 2830 Huntington Pt lt Port Coquitlam Canada 3 473 Telephone 604 464 8144 Telex 04 353637 Dredging Sonar Model 952 1 Single Axis Sonar Head c w frame Model 952 2 Single Axis Processor c w power and interface cables Option 1 Velocity of Sound Manual Entry Model 952 8 Dual Axis Sonar Head c w frame Note new frame is 435 mm 16 5 in diam Model 952 5 Dual Axis Processor c w power and interface cables Option 1 Velocity of Sound Manual Entry Specify 110V standard or 220V Stepdown transformer supplied for 220V at No Charge at time of order Model 952 4 Mast Drive for replacements only Model 952 5 Gimbal Mount Universal Deployment System Model 952 6 Processor Head Cable 30 m 100 ft Model 952 9 Extension Cable Specify length to 30 m 100 ft mex Mil Spec connectors fitted to ends Model 952 7 Case for Plotter and Processor Software 952 For HP
27. t and Known horizontal distance to specify scale These require a ground visit to the floe Using either the Bell 206 or the Commander costs would be camera operator at 300 d plus mobilization of 3000 incl freight plus aircraft time of 1800 for 3 hours plus helicopter time to ground truth at 2000 plus interpretation at 2000 Total 10 600 For little extra cost a much larger field of data may contoured Vertical resolution on the sail is 25cm resolution on the keels is likely to be 21m minimum possible 2 POLAR TECH LTD Under Ice Profiling 11 3 2 SUBMARINE SURVEY Several vehicles are available but to date no unmanned device has carried out uner ice survey successfully Details of the various submersibles are included in Appendix 2 International Submarine Engineering Ltd ISE in Vancouver manufacture a variety of vehicles uhich could be used Key issues cost day bulk which quickly increases the add on operating costs platform stability and range from point of entry The smallest the line is the DART an unmanned sub having range of about 300m radius It is small will fit down a 24 inch hole and weighs about 150 lb in air Survey speed is slow at 1 5 knots Stability is acceptable Uith clever ballasting the centre of rotation could be louered and the stability improved There are DARTs at Victoria Vancouver and Halifax With the exception of the unit at DREP the others are
28. ter Offshore Survey Ltd 2 If manpower is available drill as many calibration holes as possible to check the sonar measurements 3 If within budget mobilise a diving team out of for a day series of dives to carry out a rapid evaluation of the consolidation characteristics of the ridge and to report back on any other interesting features which the sonar has either missed or assumed to be something else Comparative costs see following Sections suggest that a diver survey uould be more than double that of the sonar system and would take twice long This in itself introduces the further uncertainty of relocating the floe each day maintaining open dive holes getting consistant flying weather and the likelihood of either the helicopter or divers being pulled off the research job in favour of their on going operations contracts POLAR TECH LTO Under Ice Profiling 5 2 1 THROUGH ICE SONAR There are several sonar systems on the market which offer a means to survey the underside of an ice sheet For supplier specifications please see Appendix I Desirable characteristics are small sonar head small ice hole ie less time spent drilling a stepping motor of sufficiently fine increment to assure adequate coverage both at the long range end of each sueep and between radii increments and a pipe lowering system which is both light for helicopter transport rigid so as to minimise flexure and torque errors
29. ydrophones references long base line algorithm to navigate with an expected positional accuracy of 2 in the horizontal mode and 0 5 in the vertical Since it is untethered all is stored via HCD 75 digital data acquisition system on a 3M tape eck having 36 Mbytes of capacity An on board doppler sonar also aids in dead reckoning The control system billed as the second most sophisticated remote in the world uses two 8086 microprocessors to control navigation sonar 0 acoustic telemetry and error detection and 8088 to trim the vehicle and store the data Since the unit has such potential and is already destined for a sister institute of IOS Pat Bay it is considered worthwhile to 0 into its design and capabilities some detail since they not covered much in the Appendix The basic unit having 10 kW hr of on board power will weigh about 3000 lb and be able to travel 50 at 5 knots Additional battery packs may be added amidships with each 10 kW hr increasing the weight by another 1000 1b Contact personnel at BIO are John Brock now an independent consultant working on ARCS Adam Kerr Hd Hydrography and Don Dinn Engrg Mngr At IOS contacts are Terry Curran and Jim Gallaway POLAR TECH LTD Under Ice Profiling 13 3 3 SCANNING LASER The scanning laser has been used widely in the Arctic to profile ice top sides and most of its operational problems have been resolve

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