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