Skip to main content

SLR Data Products and Holdings

Data Holdings

The Satellite Laser Ranging (SLR) data archived in NASA’s Crustal Dynamics Data Information System (CDDIS) are in the form of on-site normal point and full-rate data. In the early days of laser ranging data analysis, scientists typically required SLR full-rate data; these data included all valid points or returns from the satellite. Since 1988, SLR normal points have been produced from the global full-rate data set.

Normal point data are compressed data using sampling over time based upon the presence of some minimum number of data points in the sampling interval. The monthly data volume is considerably reduced. Since the early 1990s, normal point are generated on-site by laser ranging systems and transmitted daily (and sometimes hourly) to a regional processing center via electronic means.

Data Summary

The data from each satellite are stored in separate files and directories, by satellite. Each file contains all data received during the last 24-hour period. Additionally, a single file containing all data received during the last 24 hours is available.

Data from the global laser ranging network are organized in subdirectories by file content (normal points, full-rate), satellite, and year.

Data Access

Spatial Coverage

Temporal Coverage

Data Volume

  • Normal point data: ~1.25 Mbyte/day, 40 Mbytes/month
  • Full-rate SLR data: ~10 Mbytes/day (compressed)

Data Formats

  • Normal point data: Consolidated Laser Ranging Data (CRD) format, 2012 through present; ILRS Normal Point data format (formerly known as the CSTG format) prior to 2012
  • Full-rate data: Consolidated Laser Ranging Data (CRD) format, 2012 through present; ILRS Full-Rate Data format (formerly known as the MERIT-II format, V2/V3) prior to 2012

Product Holdings

Products derived from Satellite Laser Ranging (SLR) data archived in NASA’s Crustal Dynamics Data Information System (CDDIS) support scientific research in:

• Terrestrial reference frame (center of mass and scale)
•  Improve understanding of the dynamics and modeling of GNSS orbits (one of our major users)
•  Calibration and validation of ocean and ice altimetry missions
•  Static and time-varying gravity field (low order/degree terms)
•  Plate tectonics and crustal deformation
•  Earth orientation and rotation (polar motion, length of day)
•  Total Earth mass distribution
•  Space science – satellite dynamics, etc.
•  Relativity and lunar science

Product Summary

The CDDIS archive of laser ranging products consists of solutions derived by analysis centers in support of the International Laser Ranging Service (ILRS). The ILRS combination centers retrieve these solutions and produce the combined ILRS A and B solutions (generated by the primary and backup ILRS combination centers, respectively). 

Products derived from these SLR observations include precise satellite ephemerides, station positions and velocities of sites in the ILRS network, and Earth orientation parameters (EOPs) including polar motion and rates and length-of-day. ILRS analysis and combination centers deliver the precise orbit and station position/EOP products to the ILRS data centers, including CDDIS.

SLR Product Holdings

Spatial Coverage

Temporal Coverage

  • SLR station position, and EOP products since June 1976
  • SLR precise satellite orbit products since February 2016

Data Formats

Related Resources

Datasets

View All Datasets
Filters
Dataset Platform Temporal Extent Data Format
Ground-Based Satellite Laser Ranging (SLR) Observation Data (full-rate, daily, 24 hour files) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS, AJISAI, STARLETTE, STELLA, Galileo, GLONASS, Beidou, IRNSS, QZSS, LARES 1976-01-01 to Present ILRS data format, CRD format
Ground-Based Satellite Laser Ranging (SLR) Observation Data (full-rate, monthly files) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS, AJISAI, STARLETTE, STELLA, Galileo, GLONASS, Beidou, IRNSS, QZSS, LARES 1976-01-01 to Present ILRS data format, CRD format
Ground-Based Satellite Laser Ranging (SLR) Observation Data (normal points, daily, 24 hour files) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS, AJISAI, STARLETTE, STELLA, Galileo, GLONASS, Beidou, IRNSS, QZSS, LARES 2016-01-01 to Present ILRS data format, CRD format
Ground-Based Satellite Laser Ranging (SLR) Observation Data (normal points, hourly files) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS, AJISAI, STARLETTE, STELLA, Galileo, GLONASS, Beidou, IRNSS, QZSS, LARES 2010-01-01 to Present ILRS data format, CRD format
Ground-Based Satellite Laser Ranging (SLR) Observation Data (normal points, monthly files) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS, AJISAI, STARLETTE, STELLA, Galileo, GLONASS, Beidou, IRNSS, QZSS, LARES 1982-01-01 to Present ILRS data format, CRD format
Ground-Based Satellite Laser Ranging (SLR) Observation Data Summary (normal points, monthly files) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS, AJISAI, STARLETTE, STELLA, Galileo, GLONASS, Beidou, IRNSS, QZSS, LARES 1982-01-01 to Present ILRS data format, CRD format
International Laser Ranging Service (ILRS) extension of the International Terrestrial Reference Frame 2020 (ITRF2020) TRF Model with additional SLR sites from NASA CDDIS SATELLITES 1976-05-01 SINEX
Lunar Laser Ranging (LLR) data from NASA CDDIS APOLLO-SOYUZ, GROUND STATIONS, LUNOKHOD 1969-01-01 to Present
Lunar Orbiter Laser Altimeter (LOLA) one-way Laser Ranging Full Rate Data (all ranges collected, ground stations, aggregate of normal points daily) from NASA CDDIS GROUND STATIONS 2009-07-01, 2014-09-01 Consolidated Laser Ranging Data Format (CRD) version 1
Satellite Laser Ranging Mail Exploder distributing general information about ILRS-related activities to the ILRS community. SATELLITES 1983-01-01 to 2021-12-31 SINEX
Satellite Laser Ranging products International Terrestrial Reference Frame (ITRF2020) Station Positions and Earth Orientation Parameters (EOP) Time Series (REPRO2020) from NASA CDDIS SATELLITES 1983-01-01 to 2021-12-31 SINEX
Satellite Laser Ranging (SLR) data from NASA CDDIS SATELLITES 1976-01-02 to Present
Satellite Laser Ranging (SLR) Data Handling File for the International Laser Ranging Service (ILRS) extension of the International Terrestrial Reference Frame 2020 (ITRF2020) TRF Model with additional SLR sites SATELLITES 1976-05-01 to Present SINEX
Satellite Laser Ranging (SLR) Earth Orientation Parameters (EOP) Position Products from NASA CDDIS ETALON-1, ETALON-2, GROUND STATIONS, LAGEOS-1, LAGEOS-2 1976-05-16 to Present
Satellite Laser Ranging (SLR) ILRS Analysis Center (AC) Orbit Product (weekly files, generated weekly) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS 2016-01-01 to Present extended standard product-3 (SP3)
Satellite Laser Ranging (SLR) ILRS Analysis Center (AC) Position and Earth Rotation Parameters (ERP) Product (weekly files, generated daily) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS 1976-05-16 to Present Software Independent Exchange (SINEX)
Satellite Laser Ranging (SLR) ILRS Combination Center (CC) Orbit Product (weekly files, generated weekly) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS 2016-01-01 to Present extended standard product-3 (SP3)
Satellite Laser Ranging (SLR) ILRS Combination Center (CC) Station Position and Earth Rotation Parameters (ERP) Product (weekly files, generated daily) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS 1976-05-16 to Present Software Independent Exchange (SINEX)
Satellite Laser Ranging (SLR) ILRS Orbit Prediction Product (multi-day, daily, and sub-daily files) from NASA CDDIS LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GROUND STATIONS 1988-01-01 to Present CPF format (current), TIV format (prior to 2012)
Satellite Laser Ranging (SLR) ILRS Report Exploder distributing regular mission related reports. SATELLITES 1983-01-01 to 2021-12-31 SINEX
Satellite Laser Ranging (SLR) International Laser Ranging Service (ILRS) Data Handling Files SATELLITES 1976-01-01 SINEX
Satellite Laser Ranging (SLR) International Laser Ranging Service (ILRS) Eccentricity Files from NASA CDDIS SATELLITES 1968-01-01 SINEX
Satellite Laser Ranging (SLR) Observation Data Summary (full-rate, monthly files) from NASA CDDIS SATELLITES 1976-01-01 CRD, ILRS/CSTG
Satellite Laser Ranging (SLR) Predictions from NASA CDDIS ADEOS-1, ADEOS-2, AJISAI, ALOS, ANDE CASTOR, ANDE POLLUX, ANDE-RR ACTIVE, ANDE-RR PASSIVE, BE-C, BLITS, CHAMP, COMPASS-M1, CRYOSAT-1, CRYOSAT-2, DIADEM-1C, DIADEM-1D, ENVISAT, ERS-1, ERS-2, ETALON-1, ETALON-2, ETS-8, GEOS-1, GEOS-2, GEOS-3, GFO-1, GFZ-1, GIOVE-A, GIOVE-B, GLONASS, GOCE, GP-B, GPS-35, GPS-36, GRACE-A, GRACE-B, GROUND STATIONS, HY-2A, ICESAT-1, JASON-1, JASON-2, KOMPSAT-5, LAGEOS-1, LAGEOS-2, LARETS, LRE, LRO, METEOR 2-21, METEOR-2, Meteor-3, Meteor-3M, MSTI-2, OICETS, PROBA-2, QZS-1, RADIOASTRON, REFLECTOR, RESURS-01, SEASAT-1, SOHLA-1, STARLETTE, STARSHINE, STELLA, STSAT-2A, STSAT-2B, SUNSAT, TANDEM-X, TERRASAR-X, TIPS, TIPS-NORTON, TIPS-RALPH, TOPEX/POSEIDON, WESTPAC, ZEIA 1998-01-01 to Present
Satellite Laser Ranging (SLR) Satellite Orbit Products from NASA CDDIS GROUND STATIONS 1992-01-01 to Present Standard Product 3 (SP3)
You're viewing 25 of 25

Frequently Asked Questions

Earthdata Forum

Our online forum provides a space for users to browse thousands of FAQs about research needs, data, and data applications. You can also submit new questions for our experts to answer.

Submit Questions to Earthdata Forumand View Expert Responses

Earthdata
Forum