global geoid accurate to ±O.5 meter. The GMT methodology will provide a tool for
determining if the accuracy goal has been achieved.
In support of this project and others; DMA, in coordination with military and civilian
survey and mapping organizations around the world, is constructing a database of
geodetic survey control stations. This database will include data and descriptions for all
types of geodetic survey control stations, including stations suitable for the GMT
methodology. An operational date for this database has not yet been set.
CONCLUSIONS
The GMT methodology, as applied by the authors, is free from any hypothesis regarding
the geoid or the Earth's internal mass distribution. The accuracy of the GMT method is
limited only by errors in the geocentric coordinates and normal heights (or geopotential
numbers) at the testing sites. We assume that geocentric positions and normal heights at
the GMT sites can be determined with an accuracy equal to or better than that of the
geopotential model being evaluated.
The error in the geoidal potential, W o , is estimated to be ±O.l m 2 / S2. This can be
confirmed by global testing using the GMT methodology, because the error is included as
a constant in 8Wp and/or 8Rp at any given testing site.
The GMT methodology described is independent of satellite data used to develop the
geopotential model. Therefore, the accuracy estimates for geopotential model obtained
from 8Wp and/or 8Rp values can be considered realistic.
However, in order to test global geopotential models, a global GMT network should be
established. Stations in this network must have known geocentric coordinates and normal
heights (or geopotential numbers) with the sufficient accuracy.
Acknowledgment:
The authors wish to express their sincere thanks to Dr. Erricos C. Pavlis for his kind
assistance in supplying the geopotential coefficients, the SLR sites coordinates and
inspiring discussions we had on the topic via E-mail.
REFERENCES:
Bursa, M., Z. Sima, J. Kostelecky: Determination of the geopotential scale factor from
satellite altimetry. Studia geophys. et geodaet. 36 (1992), 101-108.
Eremeev, V. F., M. I. Yurkina: Theory of heights in the Earth's gravity field (in Russian).
Nedra, Moscow (1972), 144 pp.
Molodensky, M. S.: Fundamental problems in geodetic gravimetry (in Russian).
Geodezizdat, Moscow (1945), 106 pp.
Nesvorny, D., Z. Sima: Refinement of the Geopotential Scale Factor Ro on the Satellite
Altimetry Basis. Earth, Moon, and Planets 65 (1994), 79-88.
Pavlis, E.: Personal communication (1994).
Rapp, R. H.: Equatorial Radius Estimates from TOPEX Altimeter Data. Preprint 1995.
59
determining if the accuracy goal has been achieved.
In support of this project and others; DMA, in coordination with military and civilian
survey and mapping organizations around the world, is constructing a database of
geodetic survey control stations. This database will include data and descriptions for all
types of geodetic survey control stations, including stations suitable for the GMT
methodology. An operational date for this database has not yet been set.
CONCLUSIONS
The GMT methodology, as applied by the authors, is free from any hypothesis regarding
the geoid or the Earth's internal mass distribution. The accuracy of the GMT method is
limited only by errors in the geocentric coordinates and normal heights (or geopotential
numbers) at the testing sites. We assume that geocentric positions and normal heights at
the GMT sites can be determined with an accuracy equal to or better than that of the
geopotential model being evaluated.
The error in the geoidal potential, W o , is estimated to be ±O.l m 2 / S2. This can be
confirmed by global testing using the GMT methodology, because the error is included as
a constant in 8Wp and/or 8Rp at any given testing site.
The GMT methodology described is independent of satellite data used to develop the
geopotential model. Therefore, the accuracy estimates for geopotential model obtained
from 8Wp and/or 8Rp values can be considered realistic.
However, in order to test global geopotential models, a global GMT network should be
established. Stations in this network must have known geocentric coordinates and normal
heights (or geopotential numbers) with the sufficient accuracy.
Acknowledgment:
The authors wish to express their sincere thanks to Dr. Erricos C. Pavlis for his kind
assistance in supplying the geopotential coefficients, the SLR sites coordinates and
inspiring discussions we had on the topic via E-mail.
REFERENCES:
Bursa, M., Z. Sima, J. Kostelecky: Determination of the geopotential scale factor from
satellite altimetry. Studia geophys. et geodaet. 36 (1992), 101-108.
Eremeev, V. F., M. I. Yurkina: Theory of heights in the Earth's gravity field (in Russian).
Nedra, Moscow (1972), 144 pp.
Molodensky, M. S.: Fundamental problems in geodetic gravimetry (in Russian).
Geodezizdat, Moscow (1945), 106 pp.
Nesvorny, D., Z. Sima: Refinement of the Geopotential Scale Factor Ro on the Satellite
Altimetry Basis. Earth, Moon, and Planets 65 (1994), 79-88.
Pavlis, E.: Personal communication (1994).
Rapp, R. H.: Equatorial Radius Estimates from TOPEX Altimeter Data. Preprint 1995.
59