Work Plan for Implementation of READI Clusters & Minutes
Yehuda Bock, November 27, 2013
Items with this color/font indicate updates since 11/20 teleconference
News:
WG has a Wednesday 11:30 (PDT) slot for weekly teleconference. WG meeting at AGU
with program managers from NASA and NSF. UNAVCO offered to host meeting in their
reserved conference room. UNAVCO will indicate which slots are still available.
Meeting scheduled for December 11 at 4:00 PM at AGU (Marriott Marquis) room
assignment will follow).
Networks (level 0 data)
WG Decision: Focus on two GPS station clusters in Cascadia (along coast) and southern San
Andreas Fault system (SAFS) (see maps at end of work plan). SIO and JPL will analyze the
RTCM3 data from the two clusters and provide results to users in specified formats and through
CWU GPS Cockpit software, conduct intercomparisons and quality control. Target date: January
1, 2014.
15 Cascadia stations (south to north) SC02, P435, P403, P401, PABH, P397, P407, CHZZ, P396,
P395, P366, P365, CABL, P733, PTSG – These are all PBO stations.
19 SAFS stations (alphabetical order): DESC, GLRS, HNPS, P482, P483, P484, P486, P491,
P494, P505, P506, P797, PIN2, PMOB, POTR, RAAP, SIO5, SLMS, USGC – These are PBO
(12), SIO (6) and MWD (Southern California Metropolitan Water District) (1) stations. The
SAFS cluster includes collocated SIO Geodetic Modules and MEMS accelerometer packages
(GAM). Underlined stations have not yet been upgraded but are expected to be by the end of the
year. GPS data are streamed at 1 Hz, accelerometer data at 100 Hz. PBO upgraded 3 cluster
stations in the first week of November and all are available through PBO real-time server
(P484, P797, P505). SIO5 is being upgraded.
Discussed possible Bay Area cluster. Ingrid indicates that UC Berkeley is processing about
30 stations using TRACK software, by baselines.
The streaming format for the raw GPS data is RTCM 3.0 via NTRIP version 1 (note this has
been changed from version 2) protocol from PBO and IP/ports from SIO. SIO has sent IP
information to CWU. Check that CWU is able to read the RTCM data.
Marcelo indicated hardware limitations to increase the number of stations to be analyzed,
and some problems with the PPP time series. Note that southern California stations
positions provide considerably more robust solutions.
The streaming binary format for the accelerometer data has been circulated.
Action item: establish criteria for quality control (data completeness, latency, etc.). Diego has
created prototype system (see http://orolo.ucsd.edu/). WG members should review. Diego
gave an overview and several suggestions were made to improve documentation.
Ken Hudnut gave an overview on 11/13 of activities at USGS Pasadena:
Received EEW funds from LA County funds to purchase GPS equipment. Procured 40
Trimble RT9 systems with RTX and GLONASS options allowing in-the-box PPP-AR
positioning. They are providing feedback to Trimble on additional features. Trimble
maintains its own PPP service.
The receivers are being deployed along the SAF zipper array. May not stream GLONASS
data back from stations – depends on cell modem bandwidth. The RTX positions will be
streamed and available through www.scign.org site. GPS metadata changes are provided to
UNAVCO and SCEDC. There are Episensor strong-motion instruments at the zipper
stations (as well as broadband instruments).
USGS real-time data processing is also being done with GPS Solutions software and
comparisons are underway with RTX positions. Initial results favor the RTX solutions.
Freddy Blume at UNAVCO has also conducted tests of the RTX software.
Analysis (level 1 data) and Output Formats
***Check GPS cockpit for CWU solutions
The common format for intercomparison of positions/displacements is ERYO format version 2.3
CWU: Displacements will be made available from GPS-only PPP solutions developed at CWU
and JPL. Sites P491, P494, P505 and P506 have been added to processing streams and can
be viewed through GPS Cockpit. They are integrating EYRO version 2.3 format into their
system.
SIO: Displacements will be made available from GPS-only PPP-AR solutions, and
seismogeodetic PPP-AR solutions [Geng et al., 2013]. Output is binary ERYO format version
2.3 – currently includes displacements and velocity waveforms. Currently, the SIO
displacements are the result of relative network positioning (using RTD), with one site as the
fixed reference point. SIO will provide three real-time streams: GPS-only displacements,
seismogeodetic displacements (GPS + accelerometers), and raw accelerometer data streams. SIO
has integrated Cascadia cluster into PPP-AR processing and will output displacements in
EYRO format. SIO has implemented Kalman filter approach (Bock et al., 2011) to analyze
GPS displacements and raw accelerometer data. Will be made available in ERYO format.
Action item: set up intercomparison procedure, quality control. Diego is working on this.
Longer-term action item: define parameters and output format for ionosphere
Analysis (level 2 data) and Output Formats
Magnitude scaling, SIO [Crowell et al., 2013]
Early warning (S wave arrival), SIO
Finite-fault CMT, SIO [Melgar et al., 2012]
Finite-fault slip model, SIO [Melgar et al., 2013]; CWU (network information filter)
Coseismic displacements, CWU, SIO
Action item: Finalize list of level 2 products
Action item: Discuss formats for these level 2 products
Action item: Set up real-time simulations using earthquake data (2010 Mw 7.2 El MayorCucapah & 2011 Mw 9.0 Tohoku-oki earthquakes), in progress
Action item: Determine users (JPL – ionosphere, tsunami modeling) – others? Done, see below.
Near-real-time transmission of data (levels 1 and 2)
Action item: Display products through CWU GPS Cockpit. Sites P491, P494, P505 and P506
have been added to processing streams and can be viewed through GPS Cockpit. SIO is
also implementing GPS Cockpit, which can be used as a mirror for the project.
Action item: Discuss possible E-mail notification list for level 2 products.
Discussion (Ingrid and Brendan): Provide READI results as input for Moore Foundation EEW
project’s Decision Module. From Ingrid (11/13): Action item: Generate XML messages for
transmission to CISN Decision Module and/or adding the CISN to the user list
Archiving (this has been implemented at SOPAC and SCEDC)
1 Hz RINEX files (Hatanaka and UNIX compressed): SOPAC archive for all cluster stations
(available at http://geoftp01.ucsd.edu/pub/highrate/cache/rinex/)
100 Hz accelerometer data: SOPAC and SCEDC archives
(available at ***)
1 Hz displacements and velocity waveforms: Southern California Earthquake Data Center
(SCEDC) at Caltech in seismic formats (SAC and miniSEED); SIO (ERYO format version 2.3)
(available at ***)
Action item: Other archives (NCEDC???)
Users
ARIA project (Sue Owen et al.) – ERYO positions from CWU and SIO, verified
Ionosphere research (Attila Komjathy et al.) – ionosphere products, not yet defined, no time
schedule
Tsunami research (Tony Sung) – ERYO positions, to be verified
UCB: ???
READI Web Page: http://sopac.ucsd.edu/projects/realtime/READI/
References:
Bock, Y., D. Melgar, B. W. Crowell (2011), Real-Time Strong-Motion Broadband
Displacements from Collocated GPS and Accelerometers, Bull. Seismol. Soc. Am., 101, 29042925, doi: 10.1785/0120110007.
Geng, J., Y. Bock, D. Melgar, B. W. Crowell, and J. S. Haase (2013), A new seismogeodetic
approach applied to GPS and accelerometer observations of the 2012 Brawley seismic swarm:
Implications for earthquake early warning, Geochem. Geophys. Geosyst., 14,
doi:10.1002/ggge.20144.
Geng, J., D. Melgar, Y. Bock, E. Pantoli, and J. Restrepo (2013), Recovering coseismic point
ground tilts from collocated high-rate GPS and accelerometers, Geophys. Res. Lett., 40,
doi:10.1002/grl.51001.
Melgar, D., Y. Bock and B. Crowell (2012), Real-time centroid moment tensor determination for
large earthquakes from local and regional displacement records, Geophys. J. Int., doi:
10.1111/j.1365-246X.2011.05297.x.
Melgar, D., B. W. Crowell, Y. Bock, and J. S. Haase (2013), Rapid modeling of the 2011 Mw
9.0 Tohoku-oki earthquake with seismogeodesy, Geophys. Res. Lett., 40, 1-6,
doi:10.1002/grl.50590.
Melgar, D. and Y. Bock (2013), Near-Field Tsunami Models with Rapid Earthquake Source
Inversions from Land and Ocean Based Observations: The Potential for Forecast and Warning, J.
Geophys. Res., in press.
Documentation:
Extended RYO (ERYO) Protocol version 2.3, Scripps Institution of Oceanography, August 22,
2013. Mindy has circulated to all parties.
Cascadia Cluster: Blue/Red dots are READI stations (Blue – active in last 10 minutes; Red, otherwise).
Cluster sites denoted by orange circles (magnify for better discrimination).
SAFS Cluster: Blue/Red dots are READI stations (Blue – active in last 10 minutes; Red, otherwise).
Cluster sites denoted by orange circles (magnify for better discrimination).