[IGSMAIL-1577] RINEX Extensions for GLONASS

[Werner Gurtner]

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IGS Electronic Mail      Sun Apr  6  4:11:59 PDT 1997      Message Number 1577
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Author: Werner Gurtner
Subject: RINEX Extensions for GLONASS



                   Modifications in RINEX Version 2:
                   *********************************

            - RINEX Obs and Nav Files: GLONASS Extensions
                - RINEX Met Files: Sensor Informations

                              Werner Gurtner
                          Astronomical Institute
                            University of Berne

                                April 1997

1. GLONASS Extensions
*********************

Although the 2nd version of the Receiver Independent Exchange Format for GPS
data (RINEX V.2, introduced in 1990) has been prepared to allow for GLONASS or
mixed GPS/GLONASS observations, certain clarifications and extensions have been
identified to be necessary. Recent discussions with hardware and software
developers lead to an updated document of the RINEX Version 2 standard, which
is now available at the Central Bureau Information System of the International
GPS Service for Geodynamics (IGS) at JPL, Pasadena:

         ftp://igscb.jpl.nasa.gov/igscb/data/format/rinex2.txt

and at its mirror site at the Institut Geographique National (IGN), Paris:

         ftp://schubert.ensg.ign.fr/pub/igscb/data/format/rinex2.txt

A description of the GLONASS-related modifications only is also available in
the same directories as a file "glonass.txt".

Summary of the modifications
----------------------------

The following GLONASS-related modifications and extensions have been defined:

RINEX Observation Files:

- Introduction of a Time System Identifier into the header section
- Introduction of a Leap Second header line
- Clarification of the RINEX pseudorange definition
- Definition of continuation lines when more than 12 satellites per epoch
  have been observed
- Redefinition of the default values for Satellite System Identifiers in
  the satellite numbers

RINEX Navigation Message Files for GLONASS:

- A new file type (GLONASS Navigation Message File, extension .yyG) has been
  defined to account for the completely different parameterization of the
  GLONASS broadcast satellite orbits


2. RINEX Meteorological Files
*****************************

In order to improve the exchange and use of surface weather data collected at
GPS sites and to account for requests from various sources (e.g. IGS, UNAVCO)
two additional header lines in the RINEX Met Files have been defined
(met sensor model/type/accuracy line and met sensor position/height line).

The documentation file rinex2.txt has been updated correspondingly.


3. RINEX Version Number
***********************

In view of the relatively minor modifications the current version number of the
RINEX format (2) has NOT been increased.


4. Future Modifications
***********************

Future modifications might include:

- Header line accepting non-integer observation intervals
- Definition of additional observables or sensor types in the RINEX met files
  e.g.  ZD:    dry component of zenith path delay (mm)
        ZT:    total zenith path delay (mm)
        PW:    precipital water vapor (mm)
        LW:    liquid water (mm)
- Definition of additional "observables" in the RINEX obs files
  e.g.  S1,S2: signal strength or signal/noise ratio on L1 and L2
               to facilitate special investigations
- Health of signal components (RINEX nav message file) 
- Curve fit interval (RINEX nav message file) 

Comments and proposals are welcome.


[Mailed From: Werner Gurtner <GURTNER @ aiub.unibe.ch>]