The Laser Geodetic Satellite-1 (LAGEOS-1) was designed by NASA and launched on May 4, 1976. It is the first spacecraft dedicated exclusively to high-precision laser ranging and provided the first opportunity to acquire laser-ranging data that were not degraded by errors originating in the satellite orbit or satellite array.
LAGEOS is a passive platform with no power, communications, or moving parts. LAGEOS platform "operations" consist of simply the generation of the orbit predictions necessary for ground stations to acquire and track the platform.
The LAGEOS platform is covered with 426 cube corner reflectors with all but four of these reflectors made with fused silica glass. The other four reflectors are made of germanium to obtain measurements in the infrared for experimental studies of reflectivity and satellite orientation.
LAGEOS-1 and its sister platform LAGEOS-2 are very dense (high mass-to-area ratio). LAGEOS-1 and -2 provide a permanent reference point in a very stable orbit for precision Earth-dynamics measurements including crustal motions, regional strains, fault motions, polar motion and Earth-rotation variations, solid Earth tides, and other kinematic and dynamic parameters associated with earthquake assessment and alleviation.
LAGEOS did not carry any instrument to collect data. Rather, it was covered in reflectors designed for high-precision laser ranging.
Platform characteristics:
| Launch Date: | May 4, 1976 |
| Diameter: | 60 cm |
| Shape: | Sphere |
| Reflectors: | 426 corner cubes |
| Orbit: | Circular |
| Inclination: | 109.84° |
| Eccentricity: | 0.0045 |
| Perigee: | 5,860 km |
| Period: | 225 minutes |
| Weight: | 406.965 kg |
LAGEOS-1 did not acquire any data as it is a passive platform. Metrics acquired from LAGEOS are laser range values. NASA's Crustal Dynamics Data Information System (CDDIS) has a naming convention for precise orbit products from LAGEOS and similar satellite laser ranging (SLR) products:
The starting directory for these files is:
https://cddis.nasa.gov/archive/slr/products/orbits/
Append the following directory and file names to the starting directory:
SATNAME/YYMMDD/ACNAME.orb.SATNAME.YYMMDD.vNN.sp3.gz doi:10.5067/SLR/SLR_ILRSORB_001.
| Code | Meaning |
| SATNAME | etalon1, etalon2, lageos1, lageos2, ajisai, lares, larets, starlette, stella |
| YY | 2-digit year |
| MM | 2-digit month |
| DD | 2-digit day |
| ACNAME | bkg Bundesamt für Kartographie und Geodäesie (BKG) Germany dgfi Deutsches Geodätisches Forschungsinstitut (DGFI) Germany esa ESA/ESOC, Germany gfz Helmholtz Centre Potsdam German Research Centre for Geosciences (GFZ), Germany ilrsa ILRS primary combination solution - Italian Space Agency, Centro di Geodesia Spaziale "G. Colombo" (ASI/CGS), Italy ilrsb ILRS backup combination solution - Joint Center for Earth System Technology/Goddard Space Flight Center (JCET/GSFC) Greenbelt, Maryland, USA asi Italian Space Agency, Centro di Geodesia Spaziale "G. Colombo" (ASI/CGS), Italy jcet Joint Center for Earth System Technology/Goddard Space Flight Center (JCET/GSFC) Greenbelt, Maryland, USA ngsf NERC Space Geodesy Facility (NSGF) formely RGO Satellite Laser Ranging Group, United Kingdom |
| NN | numeric version number |
| gz | gzip compressed file |
NASA data are freely accessible; however, when you publish these data or works based on the data, we request that you cite the datasets within the text of the publication and include a reference to them in your reference list.
References to datasets, like the examples below, should have enough detail to provide readers of your publication with the ability to obtain the datasets and conduct their own studies based on your work. For complete provenance and understanding of specifically which parts of data were used and how; it also may be necessary to describe in detail, within the body of the publication, exactly how the data were used.
Examples of dataset citations:
Please note that a recommended citation is provided for many datasets, and when available, appears on the NASA Crustal Dynamics Data Information System (CDDIS) webpage that describes the dataset. The elements contained in the recommended citation can be reorganized for compliance with a particular reference style that is specified by a publisher.
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