Real-time IGSNetwork Management andData Exchange Interfaces
Georg Weber, BKG, Germany
IGS Analysis Center Workshop, Miami Beach, Florida, 2-6 June 2008
UDP Relay Broadcast
• Relays operated by JPL, NRCan, GA, ESOC, and GFZ since 2003
• Network management, data exchange and software provided by NRCan
• System description and status information at www.rtigs.net
NTRIP Broadcast
2003: Permanent operation for EUREF & IGS2004: RTCM Recommended Standard2006: Operated at URL www.igs-ip.net2008: „UDP Relay NTRIP Interface“ of Pilot Project
• 140 streams from 54 providers– 92 IGS, 9 prop. IGS, 29 Miscellaneous, 10 Test– ~40 via UDP from NRCan, ~100 from NTRIP resources
• ~1000 registered users, ~40 active every day• Open Source sw for NtripClient, NtripServer, NtripCaster,
stream decoding and conversion
Features
• Automated online stream user registration– Open data policy
• Online stream provider registration• Monitoring: corrupted streams, outages,
latencies, meta-data, no post-processing• Alarm system:
Notice Advisory to Broadcaster User (NABU)• ROB: http://www.igs.oma.be/real-time/
Distribution
Limits
• 200+ streams1000 simultaneously listening clients
• Need regional broadcast services– GA Australia & UNSW, EUREF Europe,
CORS/PBO U.S.A, SIRGAS South America?
• Need thematic (re-)broadcast services for specific communities– Orbit/clocks, ionospher, troposphere
Formats and Transport Protocols
• SOC: unlikely to be upgraded to GNSS
• RTCMv3: one code per frequency
• Adapt (or develop?) other format to include all GNSS observables with app. resolution
• CandidatesFormat: RTCM & BINEX,Transport: NTRIP & UDP Relay
Near Real-time Applications
• Usually don‘t need access to broadcast service
• Interest in 5...15min high-rate RINEX files
• Upload of RINEX from stream conversion to GDC
• Users should understand specifics of stream formats
Summary of current deficiencies
• RTIGS Web representation• User and stream provider registration• Precise coordinates for non IGS stations• „NTRIP Interface UDP Relay“• Format & transport protocol for orbits/clocks, observations• Bilateral (protected) stream exchange• More (Re-)Broadcast to share expected workload• Upgrade all IGS stations to real-time, close gaps• End-to-end backup concept• Mind: RTIGS is not only about orbit/clock estimation