INERTIAL AIDED POST PROCESSED KINEMATIC … AIDED POST PROCESSED KINEMATIC GPS FOR MARINE...
Transcript of INERTIAL AIDED POST PROCESSED KINEMATIC … AIDED POST PROCESSED KINEMATIC GPS FOR MARINE...
INERTIAL AIDED POST PROCESSED KINEMATIC GPS FOR MARINE
POSITIONING
An Overview of POSPac MMS
Lou Nash, Measutronics Corporation www.Measutronics.com
We too have a lot to cover in a minimal amount of time…
Please hold questions & comments until the end
CURRENT & “TIMELY”
"I had 5 seconds before you interrupted me." -- Barack Obama, 1ST 2012 Presidential Debate 10/3/12
This presentation provides an overview of how GNSS phase observations and
inertial data are used to provide a highly accurate post processed navigation
solution
OVERVIEW: Hardware & Software
In a nutshell… GPS PHASE DATA
INERTIAL DATA
TIME TAGGED VESSEL
ORIENTATION FILE
Inertial Aided Post Processed Kinematic (IAPPK) GPS
Navigation Solution
• POST PROCESSED VIRTUAL REFERENCE STATION (PPVRS) SOLUTION
BASED ON TRIMBLE’S VRSTM TECHNOLOGY
• SmartBaseTM QUALITY CHECK
• INERTIALLY- AIDED KINEMATIC AMBIGUITY RESOLUTION (IAKAR)
• IN-FusionTM: TIGHTLY COUPLED GNSS / INS SOLUTION
Summarized as a Four Step Process
1
2
3
4
POST PROCESSED VIRTUAL REFERENCE STATION (PPVRS)
BASED ON TRIMBLE’S VRSTM TECHNOLOGY
1 PPVRS
GPS: Relative Positioning
< 30 km* > 30 km * SEE SPECS PER RECEIVER TYPE
VRS Solutions Reduce Relative Positioning Errors
NMEA OUT
GGA
CMR IN
• A linked network of reference stations • Performs quality control / integrity monitoring of networked stations & their data streams • Models systematic errors within the network • Provides real time broadcast of true network RTK solution – ZERO BASELINE SOLUTION • Logs files for post processing • ESTABLISHES A COMMON REFERENCE DATUM
What is a VRSTM?
2 Applanix SmartBaseTM
RAW DATA
POTENTIAL PPVRS NETWORK
STATION SELECTION
INFO
STATION COORDINATE
INFO
Control Station Verification
SmartBaseTM Network Adjustment
PPVRS READY!
MINIMALLY / FULLY CONSTRAINED NETWORK
ADJUSTMENT
VRS SOLUTION “THROUGHOUT SURVEY
TIMELINE”
QA / QC & PPVRS READY
3 IAKAR
INERTIALLY- AIDED KINEMATIC AMBIGUITY RESOLUTION
• SINGLE KALMAN FILTER* ESTIMATES BOTH INERTIAL & GNSS ERRORS
• RAPID AMBIGUITY RESOLUTION: OUTAGES, MULTIPATH, ETC.
• AMBIGUITY “MEMORY”
* A KALMAN FILTER IS AN EFFICIENT RECURSIVE FILTER THAT ESTIMATES THE STATE OF A LINEAR DYNAMIC SYSTEM FROM A
SERIES OF NOISY MEASUREMENTS
ITERATIVE FILTER
GPS – vs - INERTIAL
A B
TIME
SHORT TERM
HUGE OVER-SIMPLICATION!!!
HUGE OVER-SIMPLICATION!!!
A B
TIME
GPS
LONG TERM
IN-FusionTM
• TIGHTLY COUPLED GNSS / INS PROCESSOR
• OPTIMIZED BY USING SmartBaseTM SOLUTION
PPVRS & INERTIAL
PROCESSING GNSS & INERTIAL, FWD & BACKWARD
EXPORT FILE
TYPICAL PROJECT
-Manual tide reading are only accurate within close proximity of gauge.
-Incapable of accounting for phase lag resulting from extrapolated tide gauges.
-Offshore borrow site
-Phase lag errors introduced into survey data
12 miles Phase difference 12 miles from tide gauge
ERROR IN TIDE READING
Offshore Borrow Site Surveys
OFFSHORE BORROW SITE
Offshore borrow site with NOAA tidal reductions 12 miles away
Offshore borrow site with post-processed tidal reductions using SBET for RTK Tides in HYPACK
125’ single beam cross sections gridded at 25’
125’ single beam cross sections gridded at 25’
NOT JUST A MULTIBEAM TOOL!!!
TYPICAL PROJECT
COMPARISON TEST
QUESTIONS?