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GNSS Station Position Products

IGS analysis centers currently provide station position and velocity solutions to the CDDIS on a daily basis; prior to mid-2012, these solutions were issued weekly. The analysis centers provide station position, velocities, daily length-of-day (LOD) and X, Y pole positions and rates, and geocenter position solutions. The IGS reference frame coordinator retrieves these solutions and produces a combined product, which is then in turn archived at the CDDIS in SINEX format. These combination solutions are considered the official IGS products, which contribute to the International Terrestrial Reference Frame (ITRF).

Solution summary files are provided by the analysis centers in which they describe their analysis methods and strategies and list processing statistics. Descriptions of AC analysis procedures and models used are available from the IGS website.

All operational IGS GNSS products, including the station position solutions, are available in subdirectories by GPS week. The station positions and velocity files are stored in Solution Independent Exchange (SINEX) format.

In 2009, 2013, and 2020, the IGS initiated “reprocessing campaigns” (repro1, repro2, and and repro3 respectively). The IGS analysis centers re-processed the GNSS data from the global network of IGS stations (from 1994 to 2007 for repro1, from 1994 through 2012/2013 for repro2, from 1994 to 2022 for repro3) to produce a fully consistent set of products utilizing the most recent models and updated processing strategies. These reprocessed solutions are available within the weekly subdirectory structure as outlined below, in /repro1, /repro2, and /repro3 subdirectories.

The starting directories for these files (GPS and GPS+GLONASS solutions) are:

and for GLONASS-only solutions:

At the end of 2022, the IGS made the decision to change the name format going forward of many of its products archived at the CDDIS. A table is available on the IGS website which compares the old and new name formats. The table can be found on the following page:

Name Format Since GPS Week 2238

Append the following directory and file names to the starting directory:

WWWW/AAA0OPSSNX_YYYYDDDHHMM_LEN_SMP_CNT.FMT.gz

as described in the table below.

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CodeMeaning
CODECODE
EMRNRCan
ESAESA
GFZGFZ
GRGGRGS
IGSIGS
JGXJAXA
JPLJPL
MITMIT
NGSNOAA/NGS
SIOSIO
USNUSNO

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CodeMeaning
CRDStation coordinates/velocities
ERPEarth orientation parameters
RESResiduals w.r.t. daily combination
SOLVariance/covariance information
SUMAnalysis summary

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CodeMeaning
ERPEarth orientation parameters
SNXSINEX format
SUMAnalysis summary
Code Meaning
WWWW GPS week
AAAanalysis center name
YYYY 4-digit year
DDD 3-digit day of year
HH 2-digit hour
MM 2-digit minute
LEN intended product period
SMP temporal product sampling resolution
CNT content type
FMT file format
.gz gzipped file

Name Format Before GPS Week 2237

Append the following directory and file names to the starting directory:

WWWW/AAAWWWWD.TYP.Z

as described in the table below.

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CodeMeaning
codCODE (3 day long arc solution)
cofCODE (1 day solution)
emrNRCan
emxNRCan (GLONASS only)
esaESA
eurEUREF
gfzGFZ
grgGRGS
gsiGSI
igrIGS rapid solution combination
igsIGS final solution combination
iguIGS ultra-rapid solution combination
jplJPL
mccMCC (GLONASS only from SLR data)
mitMIT
migMIT
nclUniversity of Newcastle
ngsNOAA/NGS
sioSIO
sirSIRGAS

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CodeMeaning
snxStation position and velocity solution
sscShortened position and velocity solution files (without matrices)
sumAnalysis summary
erpEarth rotation parameters
Code Meaning
WWWW GPS week
AAAanalysis center name/type of solution
Dday of week (0-6, 7 indicates weekly)
TYPtype of solution
.Z UNIX compressed file

The IGS combined, final station position solutions (GNSS only) are available on a weekly basis.

The starting directory for these files is:

https://cddis.nasa.gov/archive/gnss/products/   (GPS and GPS+GLONASS solutions)

Append the following directory and file names to the starting directory as described in the table below the list.

WWWW/igsyyPwwwwd.snx.Z Combined daily station position/velocity solutions (stations without DOMES numbers removed)
doi: 10.5067/GNSS/gnss_igssnx_001
WWWW/igsyyPwwwwd.ssc.Z Combined daily station coordinate solutions (stations without DOMES numbers removed)
doi: 10.5067/GNSS/gnss_igsssc_001
WWWW/igsyyPwwwwd.res.Z Residuals between AC solutions and combined solutions
doi: 10.5067/GNSS/gnss_igsres_001
WWWW/igsyyPwwwwd_all.snx.Z Combined daily station position/velocity solutions (for all stations)
doi: 10.5067/GNSS/gnss_igssnx_001
WWWW/igsyyPwwwwd_all.ssc.Z Combined daily station coordinate solutions (for all stations)
doi: 10.5067/GNSS/gnss_igsssc_001
WWWW/igsyyPwwwwd_ITR.res.Z Residuals between AC solutions and IGS Reference Frame
doi: 10.5067/GNSS/gnss_igsitrres_001
WWWW/igsyyPwwwwd_IGS.res.Z Residuals between AC solutions and cumulative solution
doi: 10.5067/GNSS/gnss_igscres_001
WWWW/igsyyPwwww.snx.Z Combined weekly station position/velocity solutions (stations without DOMES numbers removed)
doi: 10.5067/GNSS/gnss_igssnx_001
WWWW/igsyyPwwww.ssc.Z Combined weekly station coordinate solutions (stations without DOMES numbers removed)
doi: 10.5067/GNSS/gnss_igsssc_001
WWWW/igsyyPwwww.erp.Z Daily Earth rotation parameters
doi: 10.5067/GNSS/gnss_igserpp_001
WWWW/igsyyPwwww.sum.Z Solution summary file
doi: 10.5067/GNSS/gnss_igssump_001
WWWW/IGSyyPww.snx.Z Cumulative combined solution
doi: 10.5067/GNSS/gnss_igscsnx_001
WWWW/IGSyyPww.ssc.Z Cumulative combined set of station coordinates solution
doi: 10.5067/GNSS/gnss_igscssc_001
igs00p03.erp.Z Daily Earth rotation parameters since GPS week 0860
doi: 10.5067/GNSS/gnss_igserpc_001
Code Meaning
WWWW GPS week
yy2-digit year
wwwwGPS week
dday of week (0-6)
ww week of year
.Z Unix compressed file