Hybrid system using both USBL and LBL for shallow waters

OI2013 Underwater Positioning & Communication Hybrid system using both USBL and LBL for shallow waters Nicolas LARUELLE Sales Manager at OSEAN September 4th,2013 OI2013 Page 1

OVERVIEW SPECIFICATIONS PRINCIPLES Underwater postioning Surface positioning USBL positioning LBL positioning R&D Transmission & signal study Treatment Embedded electronic Specific sensors SEA TRIALS Positioning accuracy Trajectory in harbor conditions SYSTEM COMPONENTS Beacon Buoy Monitoring display unit Acoustic recovery device OI2013 Page 2

SPECIFICATIONS To position targets (divers, AUVs ) either under the sea level or at the sea surface Acoustic positioning with specific sensors GPS positioning To communicate by sending and receiving (rescue) signals Acoustic communication Radio communication To track in real-time and simultaneously up to 12 units State of the Art embedded Electronic Cutting edge Signal Processing Algorithm In obstructed and shallow water zones Specific signals and Signal Processing Algorithm Ultra Short BaseLine Technologies Autonomous and easily deployable even from lightweight boats Low power electronic Cutting edge Li-Ion batteries Compact electronic Entire positioning system fitting in a small buoy Within a large zone Combination of Long BaseLine & USBL Technologies OI2013 Page 3

PRINCIPLES Underwater positioning Radio communication BUOY GPS Time Reference Embedded Electronic Signal Processing User Interface Trajectography software MONITORING UNIT ACOUSTIC HEAD Inertial Measurement Unit (IMU) Acoustic emitter/ receiver Acoustic communication GPS Time Reference Embedded Electronic Signal Processing Acoustic emitter/ receiver BEACON OI2013 Page 5

PRINCIPLES Surface positioning BEACON Radio communication Radio communication GPS Time Reference Embedded Electronic Signal Processing Acoustic emitter/ receiver BUOY GPS Time Reference Embedded Electronic Signal Processing User Interface Trajectography software MONITORING UNIT Inertial Measurement Unit (IMU) Acoustic emitter/ receiver ACOUSTIC HEAD OI2013 Page 6

BUOY Buoy Reference Frame Target Position Pitch & Roll Heading GPS PRINCIPLES USBL positioning Time Reference Embedded Electronic Signal Processing Radio transmission Buoy Position Target Position TOA Pitch & Roll Heading User Interface Trajectography software MONITORING UNIT Terrestrial Reference Frame Buoy Position Target Position ACOUSTIC HEAD Acoustic Head Reference Frame TOA Bearing Inertial Measurement Unit (IMU) Signal Reception Acoustic Signal Position Immersion GPS Time Reference Signal Emission Depth Measure BEACON (Target) OI2013 Page 7

BUOY 1 GPS Embedded Electronic Signal Processing BUOY 2 Time Reference Buoy 1 Position Target Immersion/Buoy 1 TOA /Buoy 1 GPS Time Reference Embedded Electronic Signal Processing PRINCIPLES LBL positioning Buoy 2 Position Target Immersion/Buoy 2 TOA /Buoy 2 Buoy 3 Position Target Immersion/Buoy 3 TOA /Buoy 3 GPS Time Reference Embedded Electronic Signal Processing MONITORING UNIT Terrestrial Reference Frame 3 Buoys Position Calculated Target Position User Interface Trajectography software BUOY 3 OI2013 Page 8

R&D Transmission & Signal study Signal Treatment Embedded Electronic Specific Sensors OI2013 Page 10

TRANSMISSION STUDY Study the adequate transmission mode «Synchronous vs. Asynchronous mode» Asynchronous mode Buoy Transmitter 2x Acoustic path=>2x signal loss 2x Acoustic reception =>2x detection uncertainty interrogation Response Target Receiver Synchronous mode 1 single Acoustic path=>more efficient 1 single Acoustic reception =>less uncertainty Synchronization: both transmitter & receiver on GPS Clock Time share mode for 12 targets Buoy Receiver Target Transmitter OI2013 Page 11

SIGNAL STUDY Study the adequate signal: Criteria Signals Correlation Rejection Reflection Treatment Positioning + + + + + + + + + + Communication - - - + + + + + + + + + Signals to be analysed Phase Shift Keying (PSK) Frequency Shift Keying (FSK) Frequency Modulation (FM Sinus type) OI2013 Page 12

Amplitude normalisée (db) Amplitude normalisée (db) Amplitude normalisée (db) Amplitude normalisée (db) Amplitude normalisée (db) Amplitude normalisée (db) Trials SIGNAL STUDY Autocorrelations 0 0 0-5 -5-5 -10-10 -10-15 -15-15 -20-20 -20-0.008-0.006-0.004-0.002 0 0.002 0.004 0.006 0.008-0.008-0.006-0.004-0.002 0 0.002 0.004 0.006 0.008-0.008-0.006-0.004-0.002 0 0.002 0.004 0.006 0.008 Delais (s) Delais (s) PSK FSK FM Delais (s) Rejection & orthogonality 0 0 0-5 -5-5 -10-10 -10-15 -15-15 -20-0.008-0.006-0.004-0.002 0 0.002 0.004 0.006 0.008-20 -0.008-0.006-0.004-0.002 0 0.002 0.004 0.006 0.008-20 -0.008-0.006-0.004-0.002 0 0.002 0.004 0.006 0.008 Delais (s) Delais (s) PSK FSK FM Delais (s) OI2013 Page 13

Nombre d echantillons Nombre d echantillons Nombre d echantillons Trials SIGNAL STUDY Tolerance against reflected signals Main correlation peak Amplified secondary correlation peak S(t) S(t+Ƭ) Correlation Reflected signal: Detection error 3.5 3 2.5 1.4 1.2 1 1.4 1.2 1 2 0.8 0.8 1.5 0.6 0.6 1 0.4 0.4 0.5 0.2 0.2 0 0 5e-005 0.0001 0.00015 0.0002 0.00025 0.0003 0.00035 0.0004 Tau (s) 0 0 5e-005 0.0001 0.00015 0.0002 0.00025 0.0003 0.00035 0.0004 Tau (s) 0 0 5e-005 0.0001 0.00015 0.0002 0.00025 0.0003 0.00035 0.0004 Tau (s) PSK FM FSK - - - + + + + + OI2013 Page 14

Results SIGNAL STUDY Signals Correlation Rejection Reflection Treatment FSK + + + + + + + + + + FM - - - + + + + + + + + POSITIONING: FSK Narrow main Peaks Spaced secondary Peaks Good tolerance against reflected signals COMMUNICATION: FM Narrow main Peaks Close secondary Peaks Tolerance tagainst reflected signals : good detection/bad accuracy OI2013 Page 15

R&D Transmission & Signal study Signal Treatments Embedded Electronic Specific Sensors OI2013 Page 16

SIGNAL TREATMENT Develop the adequate algorythm OBJECTIVES FOR POSITIONING Detect identified signal Measure arrival time Measure corresponding phase For numerous channels in parallel Easy to implement Signal S1(t) Analytical Signal H(S(t)) = Sa(t) Demodulation Correlation Time of arrival 1 Instant Phase 1 Signal Sn(t) Analytical Signal H(S(t)) = Sa(t) Demodulation Correlation Time of arrival n Instant Phase n OI2013 Page 17

OBJECTIVES FOR COMMUNICATION Simultaneous detection of 12 signals Easy to implement SIGNAL TREATMENT Signal Peak clipper Limiter Bandpass filter n 1 Demodulator n 1 Detector Bandpass filter n 12 Demodulator n 12 Detector OI2013 Page 18

FOCUS Transmission & Signal study Signal Treatment Embedded Electronic Specific Sensors OI2013 Page 19

Develop the adequate hardware ADDITIONAL CONSTRAINS High accuracy Time reference Real time aquisition/processing (FS=200kSps - 5µs) Low consumption electronic As compact as possible EMBEDDED ELECTRONIC ARCHITECTURE Positioning function Communication function-rescue codes Communication function- Recall codes OI2013 Page 20

EMBEDDED ELECTRONIC POSITIONING FUNCTION 12 codes received (time share) Hydrophone signal x4 Analogic conditioning Analogic To Digital converter FPGA DSP XYZ TOA OI2013 Page 21

EMBEDDED ELECTRONIC COMMUNICATION FUNCTION: Rescue codes->buoy 12 codes simultaneously received Hydrophone signal x2 Analogic conditioning Analogic To Digital converter FPGA DSP Rescue code x12 OI2013 Page 22

EMBEDDED ELECTRONIC COMMUNICATION FUNCTION: Recall codes->beacon 2 codes simultaneously received Hydrophone signal x1 Analogic conditioning Analogic To Digital converter DSP Beacon code Common code 12cm 4.7" OI2013 Page 23

R&D Transmission & Signal study Signal Treatments Embedded Electronic Specific Sensors OI2013 Page 24

Develop the adequate equipment Buoy Acoustic Head SPECIFIC SENSORS Positioning USBL 4-hydrophone tetrahedral array 1 Inertial measurement unit Communication 1 emission transducer recall codes OI2013 Page 25

Beacon Acoustic Head SPECIFIC SENSORS Transducer for Positioning USBL & Communication Position and immersion signal Emission Rescue signal Emission Recall signal Reception OI2013 Page 26

SEA TRIALS Positioning accuracy Fixed point Multiple beacons Along underwater rope Trajectory in harbor conditions OI2013 Page 28

SEA TRIALS Position accuracy Fixed point Test conditions Harbor Area Sea floor depth: 12m Test duration: 3 hours > 2000 positions Beacon depth: 6m 7,5m radius circle Results Raw positions in 7,5m radius circle Accuracy (Std Deviation) Radius=1,42m X=1,28m Y=1,95m OI2013 Page 29

SEA TRIALS Position accuracy Multiple Beacons Test conditions 12 beacons tracted by boat 4 buoys Reference GPS on boat Sea floor depth: 15m Beacon depth: 6m test duration: 25mn > 300 positions 2 groups of 6 Beacons OI2013 Page 30

SEA TRIALS Position accuracy Multiple Beacons Results OI2013 Page 31

SEA TRIALS Position accuracy Multiple Beacons Results: High accuracy positionning-within 1m Beacons trajectory in blue Reference GPS in green OI2013 Page 32

SEA TRIALS Position accuracy Along underwater rope Test conditions Harbor Area Sea floor depth: 6m<d<15m Reference underwater rope Acoustic masking by vessels 2 divers with beacon 4 buoys Diver depth: 5m 5mn test duration > 60 positions 12 Beacon in 2 groups OI2013 Page 33

SEA TRIALS Position accuracy Along underwater rope Results High accuracy positioning Positions accuracy < 3m Detection loss: none Underwater Rope In yellow Diver 2 in Green Diver 1 in Red Forward path Return path OI2013 Page 34

SEA TRIALS Trajectory in Harbor conditions Test conditions Harbor area 4h test duration Sea floor depth: 2m<d<12m Long stretched zone Sea State: 3 Night dive 14 buoys 6 divers with beacon Reference GPS on boat Diver beetween 1m to 6m depth > 2800 positions Exercice zone with 1 beacon and 1 GPS trajectory OI2013 Page 35

SEA TRIALS Trajectory in Harbor conditions Results Path: very well followed 2.5km x 0.5km zone accurately covered High accuracy positionning Forward path Return path Buoys Start & End diving Reference GPS In pink Beacon trajectory in orange Exercice zone with 1 beacon and 1 GPS trajectory OI2013 Page 36

SEA TRIALS Trajectory in Harbor conditions Results High accuracy positionning (<5m) Very narrow area Vessels acoustic masking Reflections on concrete and steel pier Boat Concrete and steel pier USBL Mode Only USBL and LBL Mode (hybrid) First Trajectory details OI2013 Page 37

SYSTEM COMPONENTS Beacon Buoy Monitoring & trajectography display unit Acoustic recovery unit OI2013 Page 40

Develop the adequate equipment Beacon SYSTEM COMPONENTS Transducer for Acoustic Positioning & Communication Radio antenna & modem for all surface transmission GPS Antenna for time synchronization and surface positioning Embedded intelligence & time reference Flashing light for automatic alarms Li-Ion batteries OI2013 Page 41

Buoy Acoustic Head for communication, USBL & LBL positioning GPS Antenna for time synchronization and surface positioning Radio antenna & modem for all signals transmission Embedded intelligence & time reference Flashing light for signalization Li-Ion batteries SYSTEM COMPONENTS OI2013 Page 42

SYSTEM COMPONENTS Monitoring and trajectography Display Unit Radio antenna & modem for all signals transmission Computer with User Interface & Trajectography softwares Li-Ion batteries GPS Antenna OI2013 Page 43

SYSTEM COMPONENTS Acoustic Recovery Device 2-hydrophone array to localize targets: range & bearing Embedded intelligence & time reference Li-Ion batteries OI2013 Page 44

OSEAN SAS (simplified joint stock company) Founded in 2003 2013 Turnover : 1,5M 18 employees COMPANY 10 research engineers 6 technicians (electronics, mechanical, acoustics & signal processing) Located in Southern France, by TOULON French navy harbor OI2013 Page 45

COMPANY OSEAN Bulding (450 sqm) Electronics laboratory (100 sqm) Acoustic test tank OI2013 Page 46

OI2013 THANK YOU FOR YOUR ATTENTION September 4th,2013 OI2013 Page 47