Comparison NovAtel SPAN and Applanix POS MV 320 Inertial Navigation Systems Heave Filter Performance LTJG Charles J. Wisotzkey, NOAA Hydrographic Systems and Technology Programs Field Support Liaison, Pacific NOAA Western Regional Center, Seattle Email: charles.j.wisotzkey@noaa.gov
Personnel Involved: Office of Coast Survey Navigation Response Branch - Vitad Pradith (now with HYPACK) Seahorse Geomatics: - Mike Mutschler - Josh Sampey Hydrographic Systems and Technology Programs - Jack Riley, Physical Scientist - LTJG Charles Wisotzkey, NOAA
Background: NovAtel SPAN Inertial Navigation System acquired by NRB in Fall of 2014 Joint evaluation project Evaluation objectives: - Determine overall suitability for use by NOAA field units - Compare POS MV 320 and SPAN INS heave filter performance - Field test NovAtel CORRECT with PPP satellite based real-time corrector service for hydrographic survey Field test and data acquisition conducted aboard NOAA Ship Rainier Hydrographic Survey Launch 2804 from 12-18 NOV 2014
Bottom-line results, Up-front: NovAtel Post-processed Delayed Heave and Applanix TrueHeave solutions showed a mean difference of 0.000 m with a 0.025 m 2- sigma value NovAtel pseudo real-time delayed heave solution questionable NovAtel pseudo real-time delayed heave and real-time heave consistently exhibited variable phase offset
NovAtel SPAN INS System: Waypoint Inertial Explorer used for post processing Source: http://www.novatel.com/assets/documents/papers/spanbrochure.pdf
SPAN Heave Source: http://www.novatel.com/assets/documents/papers/heave_compensation.pdf
Applanix POS MV 320 V4 Industry standard Used by NOAA hydrographic field units Also used by NOAA airborne Lidar units POS Pac Mobile Mapping Suite used for post processing
POS MV 320 V4 Source: http://www.applanix.com/products/marine/pos-mv.html
One note: post-processing option in Inertial Explorer (NovAtel) for optimal results: Applanix to CARIS TrueHeave workflow:.000 files (raw POS MV data) NovAtel to CARIS delayed heave workflow: Inertial Explorer raw data.sbtc files
RA Launch 2804 Setup
Operating Environment Working Grounds: Transit from Puget Sound, WA to Newport, OR: South, Lopez Is. South Protection Is.
Swell height and period during transit from Puget Sound, WA to Newport, OR: Avg swell height of about 5 ft with period of approximately 7-8 seconds Largest swells observed were about 7 ft with period of about 10 seconds Local buoy observations, my own observations, and ship s weather log used as observation data Data was collected on the launch while it was secured on the ship - Launch position was near stern of ship and about 20ft off deck
Expected accuracies in observed conditions: Avg swells = 1.524 meters 5% 3.5% 2.5% 2% 0.0762 m 0.0533 m 0.0381 m 0.0305 m NovAtel SPAN INS
Method of Analysis and Comparison Data Extraction: Applanix POS MV heave data: - Data imported into POS Pac MMS 7.1 - TrueHeave and Real-time heave data exported using Display Plot tools NovAtel SPAN heave data: - Connect utility used to extract raw data - Custom export settings used to extract postprocessed delayed heave data Data Comparison: - Custom Python scripts used for data wrangling and comparison - Comparisons made at 5hz time intervals * Note: interpolation was conducted during data wrangling / alignment
Typical Results: Following slides contain charts that demonstrate typical results
5% value for 1.54 m swells = 15.2 cm
5% value for 1.54 m swells = 15.2 cm
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Comparison Results: POS MV real-time heave values consistently of lesser amplitudes than Applanix TrueHeave or NovAtel SPAN heave value NovAtel SPAN real-time and delayed heave (non-post processed) consistently displayed variable phase and amplitude offsets (qualitative assessment) NovAtel SPAN real-time and raw delayed heave values were highly similar (ex. for 2014_322_2804_2: mean difference 0.000007 m, with 2 sigma of 0.029400 m) POS MV TrueHeave and post-processed SPAN Delayed Heave values were highly similar (ex. for 2014_322_2804_2: mean difference 0.0007 m, with 2 sigma of 0.0285 m)
Limitations, Assessment, and Future Work: Limitations: - Evaluation consisted of familiarization and comparison work - This was NOT a ground-truth evaluation Assessment: - NovAtel SPAN post-processed solution compared well against current industry leading standard - Applanix TrueHeave is still simpler to integrate with workflow and does not require post-processing Future Work: - Work with NovAtel support to understand non-post-processed delayed heave results
Thanks and Contact Information Thanks to: - NOAA NRB for the equipment - Vitad Pradith - Mike Mutschler and Josh Sampey at Seahorse Geomatics - Command of NOAA Ship Rainier Contact Information: LTJG Charles J. Wisotzkey, NOAA Hydrographic Systems and Technology Programs Field Support Liaison, Pacific NOAA Western Regional Center, Seattle Email: charles.j.wisotzkey@noaa.gov