Subsea positioning through the ages

Transcription

1 Subsea positioning through the ages Jonathan Martin Navigation Systems Engineer Sonardyne International

2 What is sound and how can we make use of it in navigation? Applied Voltage Induced Voltage

3 The dawn of underwater acoustics 200 years ago Measuring the speed of sound in the water 1820 near Marseilles (Beudant) & 1826 Lake Geneva (Colladon and Sturm) Determined the speed of sound at 8 degc to be 1,435m/s. This is only 3m/s in error to currently accepted measurements. 10 miles apart (11.2 seconds) FLASH.. DING

4 First underwater acoustics 100 years ago Practical uses being found 1889 (Lucien Blake) suggested use of underwater bells on navigation buoys to give longer distance warning than lights and sirens in air. April 14th 1912 Titanic sinks! Lewis Richardson files a patent for underwater echo ranging and uses the first electroacoustic transducer the Fessenden Oscillator (TX+RX). The first SONAR Boston harbour trials a large iceberg is detected from 2 miles away. But he also detected and measured the distance to the seafloor 186 feet below and hence the first fathometer.

5 First underwater acoustics 100 years ago Practical uses being found 1889 (Lucien Blake) suggested use of underwater bells on navigation buoys to give longer distance warning than lights and sirens in air. April 14th 1912 Titanic sinks! Lewis Richardson files a patent for underwater echo ranging and uses the first electroacoustic transducer the Fessenden Oscillator (TX+RX). The first SONAR Boston harbour trials a large iceberg is detected from 2 miles away. But he also detected and measured the distance to the seafloor 186 feet below and hence the first fathometer.

6 First acoustic range-bearing positioning systems Drilling the Mohole in the ~1961 first DP vessel Giant transponders with seabed battery pack

7 First acoustic range-range positioning systems Long baseline systems for submarine navigation Sperry published paper on combined use of LBL and inertial navigation subsea to search for lost missiles in the ocean. LBL ~1964

8 Sonardyne early history Development of first instrumentation Range Meter MK 1

9 Sonardyne formed in 1972 Early North Sea Oil & Gas projects 1972 IOS Sand Waves 1975 BP West Sole

10 Homer Pro (2012)

11 ROV Homer (2012)

12 Rangemaster Sonardyne s First LBL

13 Before GPS - Transit

14 The Beginning of Sonardyne LBL

15 LBL Long BaseLine Vessel Tracking Seabed transponder array at known co-ordinates Single element Transceiver Ranges are observed and position calculated Very Precise Precision independent of water depth 100s/1000s of Metres

16 LBL Long BaseLine Subsea Vehicle Tracking Seabed transponder array can also be used to position subsea vehicles such as an ROV

17 SIMRAD HPR beacons

18 AODC Emergency Beacons The Wildrake Diving Incident

19 Pan & APS3 COMPATT Mk1 LF MF EHF Programmable Acoustic Navigator (PAN) Measurement of ranges to seabed transponders for LBL navigation APS3 running on a HP Series 200 or HP Series 300 Telemetry Data Loggers Template monitoring Spool-piece metrology

20 Saipem Ragno

21 Salvage of the Mary Rose (1982) Sonardyne LBL

22 Bigger projects and deeper water First tension leg platform installation Hutton field in 143m

23 Bigger projects and deeper water First tension leg platform installation Hutton field in 143m

24 TLP even deeper 2,860ft Auger Mars Ram Powell 3,214ft 2, 940ft All positioned using LBL

25 COMPATT Mk4 LF MF EHF 10 years after the release of COMPATT Mk3

26 COMPATT 5 Wideband signal technology 10 years after the release of COMPATT Mk4 20 years after the release of COMPATT Mk3

27 Correlation Processing - Tone Burst Signal Replica Reasonable Timing Detection Threshold Filter Response

28 Wideband Signals In binary phase coding the carrier is switched between +/-180 according to a digital code sequence Signal spectrum is widened by the modulation process and consists of a large number of frequency components, none of which is individually dominant. The bandwidth of Wideband signals is approximately 4kHz

29 Wideband Codes Gold codes are selected for optimal cross-correlation properties Encryption enables the separation of signals by code in addition to frequency thereby increasing the number of signals available for a finite transducer bandwidth Sonardyne Wideband uses the same type of signal technology as GPS Correlation processing enables multiple broadband signals to co-exist within the same frequency space

30 Wideband Range Correlation Processing Signal Perfect Match Replica Large Peak Very Accurate Timing Detection Threshold Response

31 Toneburst vs. Wideband Detection in Noise Toneburst Time of Arrival less accurate. Timing accuracy degrades with increasing noise. Wideband Signal Time of Arrival estimate and hence range measurement is far more accurate. 1 9 Timing Resolution Timing Resolution

32 Signal Processing Acoustic signals summary Narrowband signal (tone) Range only Ultra Wideband2 Signals = More Energy = Greater Signal to Noise Ratio = Better Performance Wideband 1 Separate range & telemetry Wideband 2 Range & telemetry of data +PLUS

33 Ormen Lange 120Km Offshore (Norwegian Coast)

34 Orman Lange Wideband Proven in an Extreme Environment Compatt 501 (C5 + SVS) Compatt 509 (C5 + DQ) Compatt 504 (C5 + DQ) Compatt 502 (C5 + SVS) Compatt 504 (C5 + DQ + Gyro) Template set down Compatt 503 (C5 + Incl.)

35 USBL - Theory of Operation LBL to USBL Long Baselines reduced to Ultra Short Baselines

36 Acoustic Positioning Techniques Ultra Short BaseLine (USBL) Centimetres Range is derived from timing and sound speed Direction is derived from differences in phase of the signal at the array transducers Precision dependent on water depth and quality of vessel sensors

37 USBL - Theory of Operation LBL to USBL Long Baselines reduced to Ultra Short Baselines

38 A History of Sonardyne 40 Years of Customer Support LUSBL Support CASIUS Trials

39 6G Products Gyro/INS Compatt Compatt6 AMT Mini Compatt

40 6G enabling large LBL arrays Gumusut, Malaysia

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42 IMU Production A platform for AHRS and INS

43 James Cook USBL Trials in 4,870m Water Depth A CASIUS in 4,870m Water Depth Bay of Biscay Statistic CASIUS Results 1 DRMS (63.2%) of observations 7.2m (0.12% of slant range)

44 Spitsbergen 80 N All true gyrocompasses degrade with latitude Track the g vector and the rate at which the g vector rotates, in order to establish the local navigation frame At the poles the g vector and the earth axis of rotation are coincident

45 AHRS practical considerations for marine use - mechanical integration, high performance USBL OTS deployment pole - Ormen Lange Field (850m depth) May 2009

46 GyroUSBL Convenience in deep water Gulf of Mexico m Water Depth Setup: HPT7000 GyroUSBL Customer over the side pole Benefit: 0.32% slant range accuracy out of the box calibration free (still needs verification) 0.13% slant range accuracy post calibration

47 Modern acoustic positioning & communication systems Remarkable precision has been achieved USBL precision <11.2 m 1DRMS, anywhere inside the miles

48 GyroCompatt GyroCompatt provides in a single housing: Heading, Heave, Pitch & Roll output Sound velocity probe Two way acoustic telemetry link (command & data) Fully functioning Compatt transponder Acoustic on/off switched internal battery pack Data logger capability for offline processing REPLACED BY Wireless AHRS Offline processing

49 Nautilus - Early Subsea Inertial Navigation

50 Subsea INS for ROV tracking USBL Aided INS Vessel GPS USBL Key Features: INS INS aided by DVL and USBL data Improved precision Ability to operate at greater depths while maintaining suitable precision

51 Long Layback and Touchdown Monitoring USBL + DVL AINS

52 OOS - Pipeline Out Of Straightness Setup: USBL, DVL and Depth aided Real Time (coarse configuration) Post Processed IRM Offline Post Processing Position Requirement: 20cm relative accuracy in 50m distance With USBL disabled for 10 minutes the real time DVL aided drift of 20cm, which can be further reduced by post processing

53 DP INS DP Desk Benefits: Higher update rate DP Telegram at 1-5 Hz Depth independent high update rate to DP desk Provides full navigation state (velocity etc) Less on the seabed Lower acoustic updates possible USBL Transceiver Lodestar INS

54 USBL aided INS (DP-INS) Some Advantages: 1Hz output to DP desk with truthful dynamics. (no crude low pass filtering or smoothing!) Improved precision Truth by post-processed GPS No drop-outs (aeration & thruster wash) = improved weather operating window Independent high accuracy velocity, angular rate and true acceleration - potential for improved DP control system performance and robustness Increased battery life update rate dependent on acoustic quality.

55 Subsea INS for ROV tracking Sparse LBL Aided INS + DVL + Depth Data Fusion Engine INS DVL Pressure Sensor + + Key Features: INS aided by DVL and range data Improved precision Ability to operate at even greater depths while maintaining suitable precision Independent verification of USBL

56 ROV INS - SPRINT Sparse LBL aided INS

57 So where are we going next? Smarter Systems, Easier To Use? So systems need to be Easy to use Wizards and short form guides Adaptive, intelligent Reliable Independence & redundancy Onshore support

58 So where are things going in the future? Automation & telepresence getting people out of the way completely 2 x Sonardyne COMPATT 6 & Waveglider deployed off US East coast Environmental monitoring as part if IOOS Oceanographic programme

59 So where are things going in the future? Automation & telepresence getting people out of the way completely 2 x Sonardyne COMPATT 6 & Waveglider deployed off US East coast Environmental monitoring as part if IOOS Oceanographic programme

60 Sonardyne BlueComm technology Real time wireless video transmission at ~2000m depth Full frame rate video transmission with black and white cameras used for low light contrast Seabed node deployed by JASON ROV to Medea depressor/ tether management system Transmission range of 100+ meters

61 Acknowledgements This presentation was compiled with the help and supporting material provided by John Partridge, Simon Partridge, Nick Street, Andrew Sedden, Bernard Kiddier, Chris Handley and Chris Pearce.

62 Thank-you THE END