Publication Database GFZ (GFZ German Research Centre for Geosciences) · 1977 · 23 citations · 0 references
Natural SciencesEarth SciencesMeteorologyGeomaticsGravitationGravityGravity AnomaliesGravity MeasurementsSatellite Data ValidationFree-air AnomaliesFree-air Gravity AnomaliesFree-air Gravity CorrectionGravity Anomaly ModelingSatellite Altimetry Gravity AnomaliesSatellite Data IntegrationSatellite Gravity MeasurementsSatellite Remote Sensing Data
The use of collocation permitted GEM 9 to be a larger field than previous derived satellite models, GEM 9 having harmonics complete to 20 x 20 with selected higher degree terms. The satellite data set has approximately 840,000 observations, of which 200,000 are laser ranges taken on 9 satellites equipped with retroreflectors. GEM 10 is complete to 22 x 22 with selected higher degree terms out to degree and order 30 amounting to a total of 592 coefficients. Comparisons with surface gravity and altimeter data indicate a substantial improvement in GEM 9 over previous satellite solutions; GEM 9 is in even closer agreement with surface data than the previously published GEM 6 solution which contained surface gravity. In particular the free air gravity anomalies calculated from GEM 9 and a surface gravity solution are in excellent agreement for the high degree terms.