Real-time GPS Positioning of the Pacific Northwest

Report
Overview
1.
(L1) Cascadia real-time GPS Station Network (PANGA + PBO)
2.
(L2) GPS processing (phase+psuedorange data -> position estimates)
3.
(L3) EEW products derived from rtGPS position streams
4.
Example earthquakes as examples – 2010 Sierra El Mayor, 2010 Maule,
2011 Tohoku-Oki
5.
GPS Cockpit Project: Managing rtGPS time series and derived products
Seattle
M6-7 crustal faults
not well known,
<1m EEW
Latency: most data arrives in less than 1 second
PANGA telemetered to CWU
PBO telemetered to UNAVCO, then to CWU
Arrival at CWU
Arrival at Boulder
Relative Positioning
Absolute (Point) Positioning
Lower absolute precision (improving)
Higher relative precision
Requires stable reference station
Requires dense network
Primarily commercial RTK
Single station-capable
Linear wrt station #
Requires rt orbit + clock corrections
Requires extensive data editing
-
(1) Relative positioning: Trimble commercial product (joint w/ WSRN and OGRN
RTK processing)
-
(2) Real-time GIPSY Point positioning:
-
(3) Developing standard GIPSY (not RTG) processing with clock and orbit correction
streams from DLR (German Aerospace Center, Munich, Hauschild)
(Method 1) Trimble T4D operated jointly with WSRN & OGRN
Trimble T4D operated jointly with WSRN & OGRN
Method 2: JPL GDGPS RT-GIPSY SYSTEM (Bar-Sever)
Method 3: CWU short-arc real-time processing with GIPSY
Requires clock corrections streamed over Ntrip (DLR, IGS
Method 3: CWU real-time processing with GIPSY
IGS Final
Method 3: CWU real-time processing with GIPSY
-Requires extensive phase-level data QC
-Less than 5s latency
~10cm deviations are common in all methods
BREW
CNCR
CHZZ
CABL
TRND
4. Example Earthquakes
2010 Maule Chile M8.8
Mike Bevis, UNAVCO
2010 Maule: Absolute point positioning of CONZ
3m
north
east
Sierra El Mayor, 4/4/2010
Good agreement between
GPS PP and Accelerometer
Data
Absolute vs. relative positioning
CWU, pp., 5 minutes
PBO, relative p., 24+24 hr
http://www.panga.cwu.edu/events/baja/
http://supersites.earthobservations.org/baja.php
pgDisplacement- 2010 Sierra El Mayor
GPS PGD
Seismic PGA
2011 Tohoku-Oki Earthquake
GEONET
GPS
ARRAY
+15s:
Seismic
Detection
NEIC W phase:
M9.0
~20 minutes
2011 Tohoku-Oki 3d GPS displacements (3x speed)
GPS Moment
Estimate
+60s: Mw 8.47
GPS Moment
Estimate
+90s: Mw 8.80
GPS Moment
Estimate
+120s: Mw 9.04
GPS Moment
Estimate
+180s: Mw 9.05
+15s:
Seismic
Detection
NEIC W phase:
M9.0
~20 minutes
60s:M8.5
90s:M8.8
120s:M9.04
-Time Series viewer (interactive): negation of false positives
-Data Aggregator (Perl, modular, talk to Craig Scrivner)
-Many new derived products:
-DefMaps
-Inversions
-GPS ShakeCast
-Assimilation into seismic EEW not obvious
GPS Cockpit
DefMap Slip
GPSCockpit
Cockpit
GPS
GPSCockpit
Cockpit
GPS
Time for a demo!
Conclusions
1.
Cascadia has mature real-time GPS networks (PANGA + PBO)
2.
Data analysis is evolving rapidly
3.
EEW products based on rtGPS position streams are also improving
4.
Recent earthquakes show the importance of rtGPS in hazards monitoring
5.
GPS Cockpit: First release on March 15

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