Analysis of altimetry over inland seas

Satellite-based altimetric data taken by GEOS-3 and SEASAT over the Black Sea and Caspian Sea are analyzed and a least squares collocation technique is used to predict the geoid undulation on a .25-degree by .25-degree grid and to transform these geoid undulations to free air gravity anomalies. This project entailed processing satellite altimeter data over inland seas for recovery of area mean gravity information. Gravity information in this area of the world is not readily available, so the possibility of obtaining it from the processing of altimeter observations is attractive. The principal objective was to complete and extend analyses done in a previous study, verify those results, and document the results and techniques. A secondary objective was to improve the algorithms and results, if possible. The approach used involved editing geoid height data to remove overland data; evaluating geoid height differences at crossover points; removing orbit errors from geoid heights using crossover differences; gridding geoid height data at .25-degree by .25-degree intervals; and estimating the gravity anomalies from gridded geoid heights using the collocation technique.