1979 **Abstract:** The spaceborne altimeter missions of Geos 3 (50‐cm accuracy) and the future Seasat (10‐cm accuracy) require precise knowledge of the radial position of the spacecraft to be most‐effective. Though errors in previous gravity models have produced large uncertainties in the orbital position of Geos 3, significant improvement has been obtained with new geopotential solutions, Goddard Earth Model (GEM) 9 and 10. The solution for GEM 9 was derived by combining laser data from Geos 3, Lageos, and Starlette; S band mea…

Help me understand this report

Search citation statements

Paper Sections

Select...

2

2

1

Citation Types

3

109

1

Year Published

1980

1982

Publication Types

Select...

2

1

Relationship

0

3

Authors

Journals

(113 citation statements)

(5 reference statements)

3

109

1

“…The new model, GEM-L2 ) has incorporated 2 1/2 years of Lageos based data in combination with satellite tracking data taken on 30 other satellites as in GEM 9 (Lerch et al, 1979). This solution, complete in spherical harmonics through degree and order 20, contained well over 600,000 laser measurements, more than half of which were taken from Lageos.…”

confidence: 99%

“…}However, because of the attenuation of the gravitational field at Tables is through le. The data on La,geos were weighted in the solution to provide for a balance both by station and by orbital arc as described in Table 2, .arising from the gravity field is contained, Also, in Figure 2. The complete set of the M-1,2 coefficients are given lit Even though a large Lageos data Set has been "sod lit GEM -W, this antellite only solution, life G M -9 (Lerch et al, 1979), still requires the utilization of a modified least squares method to achieve stability in its recovered …”

confidence: 99%

“…The potential coefficients used were the GEM 9 coefficients (Lerch et al, 1979) taken to degree 12 with P 5 assumed to be diagonal. A solution with the 1°x 10 anomalies has previously been described by Rapp (1978).…”

confidence: 99%

“…Such a solution, which also included a fourth parameter, namely N 0 the zero-degree harmonic of the geoid undulation (which provides information about the semi-major axis of the mean earth ellipsoid), was carried out by the U.S. Defense Mapping Agency Hydrographic/Topographic Center (DMAHTC) (Grappo 1979) using 290 globally balanced satellite Doppler stations. Geopotential models used for these comparisons were GEM10 (Lerch et al 1977) and GEM10B (Lerch & Wagner 1978). DMAHTC (Grappo, personal communication, July 1980) recently expanded comparisons to include GEM9 (Lerch et al 1977), Smithsonian Astrophysical Observatory (SAO) Standard Earth (SE) III (Gaposchkin 1973), SAO SE IV.3 (Gaposchkin 1976), SAO Global Gravity Field and WGS72(12,12).…”

confidence: 99%

“…Geopotential models used for these comparisons were GEM10 (Lerch et al 1977) and GEM10B (Lerch & Wagner 1978). DMAHTC (Grappo, personal communication, July 1980) recently expanded comparisons to include GEM9 (Lerch et al 1977), Smithsonian Astrophysical Observatory (SAO) Standard Earth (SE) III (Gaposchkin 1973), SAO SE IV.3 (Gaposchkin 1976), SAO Global Gravity Field and WGS72(12,12). These results, summarized in Table 2, are more conclusive since GEM, SAO and WGS72 geopotential models are practically mutually independant.…”

confidence: 99%