Products

Products derived from GNSS data archived in the CDDIS are generated and submitted by the IGS analysis and associate analysis centers. IGS products support scientific research in:

  • Realization of the International Terrestrial Reference Frame (ITRF)
  • Monitoring deformation of the solid Earth
  • Monitoring Earth rotation
  • Monitoring variations in the hydrosphere (sea level, ice sheets, etc.)
  • Scientific satellite orbit determination
  • Monitoring the Earth’s ionosphere and troposphere
  • Time and frequency transfer

 

IGS operational products include precise GNSS satellite ephemerides, positions and velocities of stations in the global GNSS network, EOPs (polar motion and rates, length-of-day), and station and satellite clock solutions. Other products derived from the CDDIS GNSS data holdings include troposphere Zenith Path Delay (ZPD) estimates (both dry and wet components) and global ionosphere maps, in support of IGS Working Groups or Pilot Projects.

Analysis + Products

The IGS collects, archives, and distributes GPS observation data sets of sufficient accuracy to satisfy the objectives of a wide range of applications and experimentation. These data sets are used by the IGS to generate the data products which are made available to interested users through this website.

IGS has decades of products that are archived which can be accessed through the ftp. Please visit the IGS Product Access Page to access IGS products.

Type Accuracy Latency Updates Sample Interval
Broadcast orbits ~100 cm real time daily
Sat. clocks ~5 ns    RMS
~2.5 ns SDev
Ultra-Rapid (predicted half) orbits ~5 cm real time at 03, 09, 15, 21 UTC 15 min
Sat. clocks ~3 ns    RMS
~1.5 ns SDev
Ultra-Rapid (observed half) orbits ~3 cm 3 – 9 hours at 03, 09, 15, 21 UTC 15 min
Sat. clocks ~150 ps RMS
~50 ps SDev
Rapid orbits ~2.5 cm 17 – 41 hours at 17 UTC daily 15 min
Sat. & Stn. clocks ~75 ps RMS
~25 ps SDev
5 min
Final orbits ~2.5 cm 12 – 18 days every Thursday 15 min
Sat. & Stn. clocks ~75 ps RMS
~20 ps SDev
Sat.: 30s
Stn.: 5 min
Note 1: Orbit accuracies are 1D mean RMS values over the three XYZ geocentric components. IGS accuracy limits, except for predicted orbits, are based on comparisons with independent laser ranging results and discontinuities between consecutive days. The precision is better.Note 2: The accuracy (neglecting any contributions from internal instrumental delays, which must be calibrated separately) of all clocks is expressed relative to the IGS timescale, which is linearly aligned to GPS time in one-day segments. The standard deviation (SDev) values are computed by removing a separate bias for each satellite and station clock, whereas this is not done for the RMS values.

Type Accuracy Latency Updates Sample Interval
Final ~3 cm 12 – 18 days every Thursday 15 min

Type Accuracy Latency Updates Sample Interval
Final positions horizontal 3 mm 11 – 17 days every Wednesday weekly
vertical 6 mm
Final velocities horizontal 2 mm/yr 11 – 17 days every Wednesday weekly
vertical 3 mm/yr

Polar Motion (PM) Polar Motion Rates (PM rate) Length-of-day (LOD)

Type Accuracy Latency Updates Sample Interval
Ultra-Rapid (predicted half) PM ~200 µas real time at 03, 09, 15, 21 UTC daily integrations at 00, 06 12, 18 UTC
PM rate ~300 µas/day
LOD ~50 µs
Ultra-Rapid (observed half) PM ~50 µas 3 – 9 hours at 03, 09, 15, 21 UTC daily integrations at 00, 06, 12, 18 UTC
PM rate ~250 µas/day
LOD ~10 µs
Rapid PM ~40 µas 17 – 41 hours at 17 UTC daily daily integrations at 12 UTC
PM rate ~200 µas/day
LOD ~10 µs
Final PM ~30 µas 11 – 17 days every Wednesday daily integrations at 12 UTC
PM rate ~150 µas/day
LOD ~10 µs
Note 1: 100 µas = 3.1 mm of equatorial rotation; 10 µs = 4.6 mm of equatorial rotation.Note 2: The IGS uses VLBI results from IERS Bulletin A to partially calibrate for LOD biases over 21-day sliding window, but residual time-correlated LOD errors remain.

Type Accuracy Latency Updates Sample Interval
Final tropospheric zenith path delay with N, E gradients 4 mm (ZPD) < 4 weeks daily 5 minutes
Final ionospheric TEC grid 2-8 TECU ~11 days weekly 2 hours;
5 deg (lon) x 2.5 deg (lat)
Rapid ionospheric TEC grid 2-9 TECU <24 hours daily 2 hours;
5 deg (lon) x 2.5 deg (lat)

IGS Final products (IGS) 
The IGS Final products have the highest quality and internal consistency of all IGS products. They are made available on a weekly basis, by each Friday, with a delay up to 13 (for the last day of the week) to 20 (for the first day of the week) days. The exception is the IGS Final Troposphere Estimates, which are produced approximately 1-7 days after the IGS Final Orbits, Clocks and Earth Rotation Parameters have been computed. The IGS Final products are the basis for the IGS reference frame and are intended for those applications demanding high consistency and quality.

IGS Rapid products (IGR) 
The IGS Rapid products have a quality nearly comparable to that of the Final products. They are made available on a daily basis with a delay of about 17 hours after the end of the previous observation day; i.e., the IGS Rapid products are released daily at about 17:00 UTC. For most applications the user of IGS products will not notice any significant differences between results obtained using the IGS Final and the IGS Rapid products.

IGS Ultra-rapid products (IGU) 
To reduce the age of the prior, discontinued Predicted orbits, the IGS started the Ultra-rapid products officially week 1087 in November 2000 (see IGSMAIL-3088) . Like the former IGS Predicted products, the Ultra-rapid products are available for real time and near real time use. The Ultra-rapid products are released four times per day, at 03:00, 09:00, 15:00, and 21:00 UTC. (Until week 1267 they were released twice daily.) In this way the average age of the predictions is reduced to 6 hours (compared to 36 hours for the old IGS Predicted products and 9 hours for the twice-daily Ultra-rapids). The shorter latency should lead to significantly improved orbit predictions and reduced errors for user applications. Contrary to all other IGS orbit products the IGS Ultra-rapid orbit files contain 48 hours of tabulated orbital ephemerides, and the start/stop epochs continuously shift by 6 hours with each update. All other orbit products contain strictly the 24 hours from 00:00 to 23:45. The first 24 hours of each IGS Ultra-rapid orbit are based on the most recent GPS observational data from the IGS hourly tracking network. At the time of release, the observed orbits have an initial latency of 3 hours. The next 24 hours of each file are predicted orbits, extrapolated from the observed orbits. The orbits within each Ultra-rapid product file are, however, continuous at the boundary between the observed and predicted parts. Normally, the predicted orbits between 3 and 9 hours into the second half of each Ultra-rapid orbit file are most relevant for true real time applications.

Precise Orbits

IGS analysis centers provide satellite orbit solutions to the CDDIS using pre-determined schedules, e.g., sub-daily, daily, or weekly, depending upon the data product. The IGS analysis center coordinator retrieves these solutions and produces a combined product, which is then in turn archived at the CDDIS. These combination solutions are considered the official IGS products.IGS orbit combination solutions are available in three forms: ultra-rapid, rapid, and final. The ultra-rapid product, useful for real-time and near real-time applications, at regular intervals four times per day; the ultra-rapid solution includes both observed and predicted satellite orbits. The rapid orbit combination is a daily solution available approximately 17 hours after the end of the previous UTC day. The final, and most consistent and highest quality IGS solutions, consists of daily orbit files, generated on a weekly basis approximately 13 days after the end of the solution week. All orbit solution files utilize the Extended Standard Product- 3 (SP3c) format.

All operational IGS GNSS products (i.e., orbits, station positions, EOP, clock solutions) are available in subdirectories by GPS week. 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.

In 2009 and 2013, the IGS initiated “reprocessing campaigns” (repro1 and repro2 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) 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 and /repro2 subdirectories.

The starting directory for these files is:

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

ftp://cddis.nasa.gov/glonass/products/   (GLONASS-only solutions)

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

WWWW/AAAWWWWD.TYP.Z

as described in the table below.

Code Meaning
WWWW GPS week
AAA analysis center name/type of solution
D day of week (0-6, 7 indicates weekly)
HH 2-digit hour (00, 06, 12, 18)
TYP type of solution
.Z UNIX compressed file

Though many products are available, the products listed below have permanent DOIs:

Though many products are available, the products listed below have permanent DOIs:

WWWW/igsWWWWD.erp.Z Earth orientation parameter solution
doi: 10.5067/GNSS/gnss_igserp_001
WWWW/igsWWWWD.sp3.Z Satellite orbit solution
doi: 10.5067/GNSS/gnss_igsorb_001
WWWW/igsWWWWD.sum.Z Orbit solution analysis summary
doi: 10.5067/GNSS/gnss_igssum_001
WWWW/igrWWWWD.erp.Z GNSS Rapid Combined Earth Rotation Parameter (ERP) Product
doi: 10.5067/GNSS/gnss_igsrerp_001
WWWW/igrWWWWD.sp3.Z GNSS Rapid Combined Orbit Solution Product
doi: 10.5067/GNSS/gnss_igsrorb_001
WWWW/igrWWWWD.sum.Z GNSS Rapid Combined Orbit Solution Summary Product
doi: 10.5067/GNSS/gnss_igsrsum_001
WWWW/iguWWWWD_HH_cmp.sum.Z GNSS Ultra-Rapid Orbit Solution Comparison Summary Product
doi: 10.5067/GNSS/gnss_igsucsum_001
WWWW/iguWWWWD_HH.erp.Z GNSS Ultra-Rapid Combined Earth Rotation Parameter (ERP) Product
doi: 10.5067/GNSS/gnss_igsuerp_001
WWWW/iguWWWWD_HH.sp3.Z GNSS Ultra-Rapid Combined Orbit Solution Product
doi: 10.5067/GNSS/gnss_igsuorb_001
WWWW/iguWWWWD_HH.sum.Z GNSS Ultra-Rapid Combined Orbit Solution Summary Product
doi: 10.5067/GNSS/gnss_igsusum_001

 

Clock Products

IGS analysis centers provide clock solutions to the CDDIS using pre-determined schedules, e.g., daily and weekly. The IGS analysis center coordinator retrieves these solutions and produces a combined product, which is then in turn archived at the CDDIS. The IGS produces clock results in two forms, tabulate at 5 minutes and 30 seconds. These combination solutions are considered the official IGS products.

IGS clock combination solutions are available in two forms: rapid and final. The rapid clock combination is a daily solution available approximately 17 hours after the end of the previous UTC day. The final, and most consistent and highest quality IGS solutions, consists of daily clock files, generated on a weekly basis approximately 13 days after the end of the solution week. All clock solution files utilize the RINEX Extensions to Handle Clock Information.

All operational IGS GNSS products (i.e., orbits, station positions, EOP, clock solutions) are available in subdirectories by GPS week. 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.

In 2009 and 2013, the IGS initiated “reprocessing campaigns” (repro1 and repro2 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) 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 and /repro2 subdirectories.

The starting directory for these files (GPS and GPS+GLONASS solutions) is:

https://cddis.nasa.gov/archive/gnss/products

ftp://cddis.nasa.gov/gnss/products/

Anonymous ftp service will be discontinued on October 31, 2020.

and for GLONASS-only solutions:

https://cddis.nasa.gov/archive/gnss/glonass

ftp://cddis.nasa.gov/gnss/glonass/

Anonymous ftp service will be discontinued on October 31, 2020.

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

WWWW/AAAWWWWD.TYP.Z

as described in the table below.

Code Meaning
WWWW GPS week
AAA analysis center name/type of solution
D day of week (0-6, 7 indicates weekly)
TYP type of solution
.Z UNIX compressed file

Though many clock products are available, the products listed below have permanent DOIs:

WWWW/igsWWWWd.clk.Z Satellite and station clock solution (5 minute)
doi: 10.5067/GNSS/gnss_igsclk5_001
WWWW/igsWWWWd.clk_30.Z Satellite and station clock solution (30 second)
doi: 10.5067/GNSS/gnss_igsclk30_001
WWWW/igsWWWWd.cls.Z GNSS Combined Final Clock Solution Comparison Summary Product
doi: 10.5067/GNSS/gnss_igscsum_001
WWWW/igrWWWWd.clk.Z GNSS Rapid Combined Satellite and Receiver Clock Solution (5 minute) Product
doi: 10.5067/GNSS/gnss_igsrclk_001
WWWW/igrWWWWd.cls.Z GNSS Combined Rapid Clock Solution Comparison Summary Product
doi: 10.5067/GNSS/gnss_igrcsum_001

 

Reference Frames

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 and 2013, the IGS initiated “reprocessing campaigns” (repro1 and repro2 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) 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 and /repro2 subdirectories.

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

Anonymous ftp service will be discontinued on October 31, 2020.

and for GLONASS-only solutions:

Anonymous ftp service will be discontinued on October 31, 2020.

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

WWWW/AAAWWWWD.TYP.Z

as described in the table below.

Code Meaning
WWWW GPS week
AAA analysis center name/type of solution
D day of week (0-6, 7 indicates weekly)
TYP type 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:

ftp://cddis.nasa.gov/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
yy 2-digit year
wwww GPS week
d day of week (0-6)
ww week of year
.Z Unix compressed file

 

Ionosphere

Since 1998, IGS associate analysis centers have provided products containing ionosphere vertical total electron content (TEC) maps and daily GNSS satellite differential code bias (DCB) values derived from the dual-frequency GNSS data. Daily ionospheric fluctuation maps are also available. The IGS product is derived from analysis center solutions, both rapid and final. These ionosphere products are available in a rapid solutions with a latency of less than 24 hours, a final solution with a latency of approximately 11 days, and a predicted solution, available both one and two days prior. Ionosphere products are provided in IONEX (ionosphere exchange) format.

The starting directory for the current ionospheric solution files is:

ftp://cddis.nasa.gov/gnss/products/ionex/

Append the following directory and file names to the starting directory for current files:

YYYY/DDD/AAAgDDD#.YYi.Z

Vertical total electron content (TEC) maps

 

YYYY/DDD/rotiDDD0.YYf.Z

Daily ROTI (rate of TEC index) product

 

as described in the table below.

Code Meaning
YYYY 4-digit year
DDD 3-digit day of year
AAA Analysis center name
# file number for the day, typically 0
YY 2-digit year
.Z Unix compressed file

 

The IGS analysis centers re-processed the historical IGS data set (from 1994 to 2007 for repro1, from 1994 through 2012/2013 for repro2) to produce a fully consistent set of products utilizing the most recent models and updated processing strategies.

 

Troposphere

IGS associate analysis centers generate troposphere products from ground-based GNSS data. These products include five-minute estimates of zenith path delay (ZPD) and north and east troposphere gradient components. Data are available in daily files by site for over 350 GNSS stations in the IGS network. Measurements of surface pressure and temperature at GNSS sites allow the extraction of precipitable water vapor from the total zenith path delay. Final troposphere estimates for over 350 stations in the IGS network. The troposphere products utilize the IGS final satellite, orbit, and EOP products and are therefore available approximately three weeks following the observation day. Troposphere products are available in a standard, IGS format.

Since the inception of the troposphere product, three analysis groups (GFZ, JPL, and currently USNO) have generated the IGS combination solution each using different methodologies. Therefore, the resulting file types have changed through the years. The current product consists of files containing daily ZPD estimates for selected sites in the IGS network. The original product consisted of one file per site per GPS week.

Historical tropospheric products are also available. These products are no longer updated.

The starting directory for the current troposphere solution files is:

Append the following directory and file names to the starting directory for current files:

TYP/SSSSDDD#.YYzpd.gz

as described in the table below.

Code Meaning
TYP type of solution (zpd or sub, analysis center input products to combined zpd product)
SSSS IGS monument name
DDD 3-digit day of year
# file number for the day, typically 0
YY 2-digit year
.gz gzip compressed file

 

The starting directories for the historical troposphere product files are:

Starting Directory Products
ftp://cddis.nasa.gov/gnss/products/troposphere/cmp/ Comparison results between initial IGS troposphere product (generated by GFZ) and JPL solution (through 2009)
ftp://cddis.nasa.gov/gnss/products/troposphere/old/ Earlier versions of IGS troposphere products, produced by GFZ
ftp://cddis.nasa.gov/gnss/products/troposphere/rpt/ Product reports by GPS week, produced by JPL (through 2009)
ftp://cddis.nasa.gov/gnss/products/troposphere/sta/ Reports and supporting information on station troposphere products, produced by JPL (through 2009)

 

Differential Code Biases (DCBs)

Differential Code Biases (DCBs) are the systematic errors, or biases, between two GNSS code observations at the same or different frequencies. DCBs are required for code-based positioning of GNSS receivers, extracting ionosphere total electron content (TEC), and other applications. Proper knowledge of DCBs is crucial to many navigation applications but also non-navigation applications such as ionospheric analysis and time transfer. With all of the new signals offered by modernized and new GNSS constellations, analysts now require a comprehensive multi-GNSS DCB product.

As part of the IGS Multi-GNSS Experiment (MGEX) two different DCB products are determined by two analysis groups: Institute of Geodesy and Geophysics (IGG) of the Chinese Academy of Sciences (CAS) in Wuhan and the Deutsche Forschungsanstalt für Luftund Raumfahrt (DLR) in Germany. These files are archived at the CDDIS:

ftp://cddis.nasa.gov/gnss/products/bias/

The satellite and station biases computed by the Institute of Geodesy and Geophysics (IGG) of the Chinese Academy of Sciences (CAS) in Wuhan are generated on a daily basis with a latency of 2-3 days and made available in daily BSX files. The constellations and signals analyzed by the IGG CAS are:

Constellation Analyzed Signals
GPS C1C,C1W,C2L/S/X,C2W,C5Q/X
GLO C1C,C1P,C2C,C2P
GAL C1C/X,C5Q/X,C7Q/X,C8Q/X
BDS C2I,C6I,C7I

 

Reference: Wang N., Yuan Y., Li Z., Montenbruck O., Tan B. (2016) Determination of differential code biases with multi-GNSS observations, Journal of Geodesy, Vol. 90, No. 3, pp. 209-228, DOI 10.1007/s00190-015-0867-4

The DLR product is updated on a 3-monthly basis and comprises weekly averages of the satellite biases. In addition a full set of daily satellite and station biases is provided for reference purposes and trend analyses. The constellations and signals analyzed by the DLR are:

Constellation Analyzed Signals
GPS C1C,C1W,C2L/S/X,C2W,C5Q/X
GLO C1C,C1P,C2C,C2P
GAL C1C/X,C5Q/X,C7Q/X,C8Q/X), in addition GAL(C6C) since Q2/2017
BDS C2I,C6I,C7I

 

Reference: Montenbruck O., Hauschild A., Steigenberger P. (2014), Differential Code Bias Estimation using Multi-GNSS Observations and Global Ionosphere Maps, Navigation – Journal of the ION, Vol. 61, No. 3, pp. 191-201, DOI 10.1002/navi.64

Data Format

The CAS DCBs are provided in a preliminary version of the Bias SINEX (BSX) format whereas DLR used the Version 1.00 of February 2016 until Q4/2016 and the Version 1.00 of December 2016 starting with Q1/2017. The December 2016 version of the Bias SINEX format uses a 4-digit year number whereas the version of February 2016 uses a 2-digit year number for specifying the validity intervals.

Bias SINEX 0.01
http://www.biasws2012.unibe.ch/docs/sinex_bias_0.01-2.txt

Bias SINEX 1.00 (February 2016)
http://www.aiub.unibe.ch/download/bcwg/format/draft/sinex_bias_100_feb07.pdf

Bias SINEX 1.00 (December 2016)
http://www.aiub.unibe.ch/download/bcwg/format/draft/sinex_bias_100_dec07.pdf

File Naming

The DCB file names

CAS0MGXRAP_YYYYDDD0000_01D_01D_DCB.BSX.gz
DLR0MGXFIN_YYYY0010000_NNU_07D_DCB.BSX.gz
DLR0MGXFIN_YYYY0010000_NNU_01D_DCB.BSX.gz

are based on a new naming scheme proposed for future MGEX products, which is inherited from the new RINEX3 file naming convention; the full specification is given as

AAAVPPPTTT_YYYYDDDHHMM_LEN_SMP_CNT.FMT[.?*]

where:

Position in Filename Code Meaning
01-03 AAA 3-char AC name; here:
CAS = Chinese Academy of Sciences
DLR = German Aerospace Center
04 V 1-char version/solution identifier; here: nominally 0
05-07 PPP 3-char campaign/project specification; here: MGX
08-10 TTT 3-char product type specification; here:
RAP = rapid
FIN = final
11 _ 1-char separator (underline)
12-15 YYYY 4-digit year of start epoch
16-18 DDD 3-digit day-of-year of start epoch
19-20 HH 2-digit hour of start epoch; here: 00
21-22 MM 2-digit minute of start epoch; here: 00
23 _ 1-char separator (underline)
24-26 LEN 2-digits+1-char intended (nominal) product period; here:
01D for 1-day
01Y for 1-year
??L for coverage interval in months
27 _ 1-char separator (underline)
28-30 SMP 2-digits+1-char sampling interval; here:
01D = 1-day averages
07D = 7-day averages/td>
31 _ 1-char separator (underline)
32-34 CNT 3-char content type; here: DCB
35 . 1-char separator (dot)
36-38 FMT 3-char format extension; here: BSX
39 (optional) . 1-char separator (dot)
40-xx (optional) extension compression file type; here: gz

 

Real-Time

The CDDIS provides access to products generated from real-time data streams in support of the IGS Real-Time Service. Two types of products are archived, igt and igc.

The igt solution is a batch combination based on daily clock and sp3 submissions by IGS real-time analysis center. These clock products have been provided since February 2009, shortly after real-time streams were routinely available through the IGS Real-Time Pilot Project and prior to the availability of real-time product streams.

The igc solution is one of the RTS solutions generated by decoding the real-time product streams. The igc files are derived from the IGC01 solution, which uses the real-time data streams that are referred to the satellite center-of-mass (CoM).

  • orbit files (igcWWWWD.sp3.Z) contain the decoded orbit and clock results from the IGC01 real time stream at 30 second intervals
  • clock solution files (igcWWWWD.clk.Z) consist of decoded clock results from the IGC01 real time stream at 10 second intervals
  • solution summary files (ritWWWWD.sum.Z) consist of orbit and clock comparisons of all the AC and combination streams against IGS rapid solution

The CDDIS also provides real-time streaming corrections through its real-time caster. A description of these solutions is available from the IGS RTS website product page.

The starting directory for these files is:

Anonymous ftp service will be discontinued on October 31, 2020.

Append the following file names to the starting directory:

WWWW/SSSWWWWD.TYP.Z

as described in the table below.

Code Meaning
WWWW GPS week
SSS solution type (igc, igt, or rit=comparison summary)

IGC
IGT
RIT
  • Global Navigation Satellite System (GNSS) Orbit and Clock Comparison Summary for the IGS AC and Combination Real-Time Products with the IGS Rapid Products from NASA CDDIS
    doi: 10.5067/GNSS/GNSS_IGSRTCSUM_001
D day of week (0-6, 7 indicates weekly)
TYP type of solution (clk=clock correction, sp3=orbit, or sum=solution summary)
.Z Unix compressed file