The Joint Gravity Model 3

Abstract

An improved Earth geopotential model, complete to spherical harmonic degree and order 70, has been determined by combining the Joint Gravity Model 1 (JGM 1) geopotential coefficients, and their associated error covariance, with new information from SLR, DORIS, and GPS tracking of TOPEX/Poseidon, laser tracking of LAGEOS 1, LAGEOS 2, and Stella, and additional DORIS tracking of SPOT 2. The resulting field, JGM 3, which has been adopted for the TOPEX/Poseidon altimeter data rerelease, yields improved orbit accuracies as demonstrated by better fits to withheld tracking data and substantially reduced geographically correlated orbit error. Methods for analyzing the performance of the gravity field using high‐precision tracking station positioning were applied. Geodetic results, including station coordinates and Earth orientation parameters, are significantly improved with the JGM 3 model. Sea surface topography solutions from TOPEX/Poseidon altimetry indicate that the ocean geoid has been improved. Subset solutions performed by withholding either the GPS data or the SLR/DORIS data were computed to demonstrate the effect of these particular data sets on the gravity model used for TOPEX/Poseidon orbit determination.

An investigation of ocean tides derived from along‐track altimetry

“…POSEIDON data are not used. The T/P orbit is corrected using the Joint Gravity Model (JGM) 3 [Tapley et al, 1996]. The T/P sea surface height data is gridded to 1 Hz intervals.…”

Constraints from orbital motions around the Earth of the environmental fifth-force hypothesis for the OPERA superluminal neutrino phenomenology

“…EIGEN-6 was released by the GeoForschungsZentrum (GFZ), AIUB-CHAMP03S was produced by the Astronomisches Institut, Universität Bern (AIUB), while GOCO2S and GO-CONS were released by the Gravity Observation COmbination (GOCO) consortium. The background gravity models adopted for AIUB-CHAMP03S were the pre-CHAMP/GRACE/GOCE JGM3 [69] [64], the formal σ C 2,0 of EIGEN-6 is smaller than those of the models to be tested by about 1 order of magnitude. Instead of using a single coefficient Table 1: First row: uncertainty δC 2,0 in the even zonal of degree ℓ = 2 evaluated according to the method by Wagner and McAdoo [64].…”

Integrated use of altimeter and in situ data for understanding the water exchanges between the Tyrrhenian and Ligurian Seas

“…The AVISO raw T/P data were at 1-s intervals (corresponding to -6.2 km along the subsatellite track). Sea surface heights (SSHs) were computed using an improved gravity model [Tapley et al, 1996] and the corrections are summarized in Table 1 , and the usual detrending of residual errors is no longer necessary. However, a mean value along the whole track segment for each cycle has been removed in order to reduce some pressure/inverse barometric correction residual effects.…”