Table 4. Geoid undulation differences.
Fields
Total RMS (cm)
JGM-3A
JGM-2
23
JGM-3B
JGM-2
29
JGM-3D
JGM-2
28
JGM-3A
JGM-3D
13
JGM-3B
JGM-3D
1
JGM-3A
JGM-3B
13
The intercomparisons of geoid differences of the JGM-2, JGM-3A, JGM-3B, and JGM3D are summarized in Table 4. By adding the GPS data, the geoid changed 13 cm in total
RMS. The differences over land were larger than those over the ocean.
FUTURE PROSPECT
Although the TIP mission has demonstrated that the GPS tracking data provide a
significant improvement in the gravity field modeling, the TIP altitude of 1330 km was
not an optimal altitude for the purpose of geopotential parameters determination. Since
the tracking of lower satellites using GPS will continue, including the data from the GPSMET, Orsted, and Geosat Follow-On mission, these data could contribute more than the
TIP to the global gravity field determination in the future.
CONCLUSION
The results presented here demonstrate that the GPS data collected by a low earth orbiting
satellite contributed to significant improvement of the global gravity field determination.
The geographically correlated errors in the gravity model are reduc(~d significantly by
using the continuous tracking provided by the GPS. The GPSIDR data contributed more
than the SLRlDORIS data on the gravity solution resulted from including both data sets.
Acknowledgment. The authors gratefully acknowledge the support of NASAlJPL
Contract 958862. Additional computing resources provided by the High Performance
Computing Facility of the University of Texas at Austin. The data preprocessing effort by
S. Byun and Y. Nam is deeply appreciated. S. Poole made significant contribution to the
gravity solution.
REFERENCES
Bertiger, W., Bar-Sever, Y., Christensen, E., Davis, E., Guinn, J., Haines, B., IbanezMeier, R., Jee, J., Lichten, S., Melbourne, W., Muellerschoen, R., Munson, T., Vigue,
Y., Wu, W., Yunck, T., Schutz, B., Abusali, P., Rim, H., Watkins, M., and Willis, P.
(1994). GPS precise tracking of TOPEXIPOSEIDON: results and implications, J.
Geophys. Res., 99(CI2), 24449-24464.
Eanes, R. (1994). Diurnal and semidiurnal tides from TOPEXIPOSEIDON altimetry,
EOS Transactions, AGU, vol. 75, no. 16.
46
Fields
Total RMS (cm)
JGM-3A
JGM-2
23
JGM-3B
JGM-2
29
JGM-3D
JGM-2
28
JGM-3A
JGM-3D
13
JGM-3B
JGM-3D
1
JGM-3A
JGM-3B
13
The intercomparisons of geoid differences of the JGM-2, JGM-3A, JGM-3B, and JGM3D are summarized in Table 4. By adding the GPS data, the geoid changed 13 cm in total
RMS. The differences over land were larger than those over the ocean.
FUTURE PROSPECT
Although the TIP mission has demonstrated that the GPS tracking data provide a
significant improvement in the gravity field modeling, the TIP altitude of 1330 km was
not an optimal altitude for the purpose of geopotential parameters determination. Since
the tracking of lower satellites using GPS will continue, including the data from the GPSMET, Orsted, and Geosat Follow-On mission, these data could contribute more than the
TIP to the global gravity field determination in the future.
CONCLUSION
The results presented here demonstrate that the GPS data collected by a low earth orbiting
satellite contributed to significant improvement of the global gravity field determination.
The geographically correlated errors in the gravity model are reduc(~d significantly by
using the continuous tracking provided by the GPS. The GPSIDR data contributed more
than the SLRlDORIS data on the gravity solution resulted from including both data sets.
Acknowledgment. The authors gratefully acknowledge the support of NASAlJPL
Contract 958862. Additional computing resources provided by the High Performance
Computing Facility of the University of Texas at Austin. The data preprocessing effort by
S. Byun and Y. Nam is deeply appreciated. S. Poole made significant contribution to the
gravity solution.
REFERENCES
Bertiger, W., Bar-Sever, Y., Christensen, E., Davis, E., Guinn, J., Haines, B., IbanezMeier, R., Jee, J., Lichten, S., Melbourne, W., Muellerschoen, R., Munson, T., Vigue,
Y., Wu, W., Yunck, T., Schutz, B., Abusali, P., Rim, H., Watkins, M., and Willis, P.
(1994). GPS precise tracking of TOPEXIPOSEIDON: results and implications, J.
Geophys. Res., 99(CI2), 24449-24464.
Eanes, R. (1994). Diurnal and semidiurnal tides from TOPEXIPOSEIDON altimetry,
EOS Transactions, AGU, vol. 75, no. 16.
46