The Geodetic and Earth Orbiting Satellite 3 (GEOS-3) was the third in a series of geodetic missions initiated by NASA. GEOS-3 objectives included defining the structure of the earth's irregular gravitational field and refining the locations and magnitudes of the large gravity anomalies, comparing results of the various systems onboard the spacecraft to determine the most accurate and reliable system, and mapping the ocean surfaces.

Mission Instrumentation:

The following instrumentation was onboard this spacecraft:

Two C-band antenna
S-band antenna
ATS/relay antenna
VHF antenna
Radar altimeter
Doppler beacon
Retroreflector array

Mission Parameters:

GEOS-3 Parameters
Sponsor:	NASA
Expected Life:	unknown
Primary Applications:	ocean mapping and gravity
Primary SLR Applications:	gravity
COSPAR ID:	7502701
SIC Code:	1127
NORAD SSC Code:	7734
Launch Date:	9 April 1975
RRA Diameter:	22.5 inches
RRA Shape:	annulus
Reflectors:	264
Orbit:	circular
Inclination:	115 degrees
Eccentricity:	0.001
Perigee:	824 km
Period:	102 minutes
Weight:	346 kg

Additional Information:

Web sites:

JPL PODAAC

Publications:

Chapman, M.E. and Talwani, M., "Comparison of Gravimetric Geoids with GEOS-3 Altimetric Geoid", J. Geophys. Res., Vol. 84, pp. 3803-3816, 1979.
Eren, K., "Spectral Analysis of GEOS-3 Altimeter Data and Frequency Domain Collocation", OSU-Rpt. 297, 151pp, 1980.
Kahn, W. D., S. M. Klosko, and W. T. Wells, "Mean gravity anomalies from a combination of Apollo/ATS 6 and GEOS-3/ATS 6 SST tracking campaigns," J. Geophys. Res., 87, 2904-2918, 1982.
Klosko, S.M., Lerch, F.J., Belott R.P., and Litkowski, E.M., "Laser Reference Orbits and Altimeter Validation for GEOS-3", Marine Geodesy Symposium, RSMAS, U. Miami, 1978.
Lemoine, F.G., "The 1998 to 1999 GEOS-3 Tracking Campaign: Analysis and Results", NASA Tech. Rept., NASA Goddard Space Flight, Jan 01, 1999.
Lerch, F.J., Klosko, S.M., Laubscher, R.E., and Wagner, C.A., "Gravity Model Improvement Using GEOS-3 (GEM 9 and 10)", NASA Doc. No. X-921-77-246, 121pp, 1977.
Lerch, F.J., Klosko, S.M., Laubscher, R.E., and Wagner, C.A., "Gravity Model Improvement Using GEOS-3 (GEM-9 and 10)", NASA X-921-77-246, September, 1977.
Lerch, F. J., Klosko, S. M., Laubscher, R. E., Wagner, C. A., "Gravity Model Improvement Using GEOS-3 (GEM-9 and 10)", J. Geophys. Res., 84(138), 3897-3915, 1979.
Marsh, J.G., Marsh, B., Conrad, T., Wells, W., and Williamson, R., "Gravity Anomalies Near the East Pacific Rise with Wavelengths Shorter than 3300 km Recovered from GEOS-3, ATS-6, Satellite-to-Satellite Doppler Tracking Data", The Use of Artificial Satellites for Geodesy and Geodynamics, pp. 296-342, 1979.
Marsh, J.G., Martin, T., McCarthy, J.J., and Chovitz, P., "Estimation of Mean Sea Surfaces in the North Atlantic, the Pacific, and the Indian Ocean Using GEOS-3 Altimetry Data", The Use of Artificial Satellites for Geodesy and Geodynamics, pp. 414-447, 1979.
Marsh, J.G., Koblinsky, C.J., Zwally, H.J., Brenner, A.C., and Beckley, B.D., "A Global Mean Sea Surface Based Upon GEOS-3 and SEASAT Altimeter Data", J. Geophys. Res., in press, 1992.
Mather, R., Lerch, F.J., Rizos, C., Masters, E., and Hirsch, B., "Dynamic Sea Surface Topography from GEOS-3 Altimetry: Determination of Some Dominant Parameters", The Use of Artificial Satellites for Geodesy and Geodynamics, pp. 448-477, 1979.
Mather, R.S., Lerch, F.J., Rizos, C., Masters, E.G., and Hirsch, B., "Determination of Some Dominant Parameters of Global Dynamic Sea Surface Topography from GEOS-3 Altimetry", - NASA TM-79558, 40pp, 1978.
Rapp, R. H., "Gravity anomalies and sea surface heights derived from a combined GEOS 3/Seasat altimeter data set," J. Geophys. Res., 91, 4867-4876, 1986.
Schutz, B.E., Tapley, B.D., Ries, J.C., and Eanes, R.J., "Polar Motion Results From GEOS-3 Laser Ranging", J. Geophys. Res., 84(B8), July 30, 1979.