RT-IGS Frequently Asked Questions

1. How do I contribute to the Real-Time International GNSS Service (RTIGS) ?
   
   Contact the RTIGS working group.
   
   
2. Are there tools to enable station operators to contribute data to the RTIGS?
   
   Yes. There are software tools that read data from AOA Benchmark, Ashtech/Thales, Javad and Topcon receivers and compress and transmitt the observation data in the RTIGS format. Another software tool is available to translate observation data from NTRIP to RTIGS (currently Ashtech, Javad, Topcon and Binex formatted data is supported) protocol.  For more information concerning available software tools.
   
   
3. What is the RTIGS Protocol?
   
   The RTIGS protocol is the User Datagram Protocol (UDP) which is a standard Internet Protocol. UDP is a message based protocol and is strongly suited to real-time data delivery.  For more information concerning the RTIGS protocol.
   
   
4. What is the Format of the RTIGS data ?
   
   All RTIGS Pilot data is in the RTIGS format. There are 4 messages types in the RTIGS format:
   1. Station Message
   2. Observation Message see the following link for more information : http://gipsy.jpl.nasa.gov/igdg/papers/SOC_FORMAT.ppt
   3. Ephemeris Message
   4. Meterological Message
   
   For more information in the message format see message content section .
   
   
5. What are the RTIGS message rates?
   
   The Pilot RTIGS message rates are:
   
   • station messages should be issues at least two times per hour;
   • observation data must be issued once a second on the second,
   • ephemeris messages must be issued when the IODE changes and meterological observation should be issued at least once every 5 minutes.
   
   
6. What is the typical RTIGS message latency ?
   
   Messages latency is a critical component of a real-time system. Typically digital land based communication networks delivery suffient performance. Satelite based communication networks are slower. The RTIGS latency objective is to deliver observations within 2 seconds. The clock starts ticking from the time the GPS satelite issues the observation to the time the user recieves the RTIGS message. For current RTIGS performance information: click on the station label.
   
   
7. How do I access real-time data from the RTIGS?
   
   Natural Resources Canada (NRCan), provides public access to all RTIGS data. A GUI client tool is available for the Windows XP (Service Pack 2) and Linux (Red Hat Enterpise 4) operating systems. To access this data stream contact NRCan to get the required tools and information.
   
   See FAQ 11. for information about accessing RTIGS data through NTRIP.
   
   
8. How do I convert RTIGS Format into RINEX or a standard Computer record?
   
   The TEQC software developed by UNAVCO transforms RTIGS formated data into Standard RINEX. The TEQC software is available at: http://facility.unavco.org/software/teqc/teqc.html
   
   NRCan privides a developers kit that reads and decode RTIGS formatted data. Contact NRCan for more information about the developers kit.
   
   
9. How do I get RTIGS Network Status Information?
   
   For a time series of message latency and delivery for all stations : click on the station label.
   
   An email based notification system is also available, to request this service contact NRCan.
   
   
10. Can I use NTRIP to contribute to the RTIGS?
    
    Yes. NTRIP can be used to contribute data to the RTIGS Pilot. Currently NRCan operates a gateway that translates : BINEX, Thales/Ashtech and Javad/Topcon formatted data into RTIGS format and protocol. Visit: http://igs.bkg.bund.de/index_ntrip_prov.htm for information about contributing to the RTIGS through NTRIP.
    
    
11. Can I use NTRIP to access RTIGS data?
    
    Yes. Access to RTIGS data is provided through the BKG RTIGS NTRIP Interface see: http://www.igs-ip.net/home.
    
    
12. What GNSS Constellations does the RTIGS support?
    
    Currently the RTIGS Tools only supports the Global Positionning System. Generic Support of all GNSS data is planned.