
Accession Number : AD0384824
Title : ADAPTED REFERENCE ELLIPSOID FOR THE NWL8D GEODETIC PARAMETER SOLUTION.
Descriptive Note : Technical memo.,
Corporate Author : NAVAL WEAPONS LAB DAHLGREN VA
Personal Author(s) : Groeger,Walter J.
Report Date : OCT 1967
Pagination or Media Count : 59
Abstract : An adapted reference ellipsoid is developed for geodetic parameter solutions with application to the NWL8D Solution. Mean sea level (geoid) is defined by a suitably chosen equipotential surface of the gravity field resulting from the geodetic parameter solution under consideration. Starting from a corresponding worldwide geoid height table which is based on one of the standard reference ellipsoids, a twoparameter solution for the ellipsoid parameters determines that ellipsoid which minimizes the area weighted sum of the squares of the geoid heights. Included are a detailed description of the twoparameter solution, a related computer program formulation and numerical data which concern the NWL8D solution as well as the associated geoid heights above both the Kaula ellipsoid and the (adapted) NWL8D ellipsoid. Also discussed is an alternative approach to the ellipsoid determination. This interprets the first two expansion coefficients of the earth's gravity potential as numbers which carry, implicity, the information necessary to specify a meaningful adapted ellipsoid which is essentially identical to the one derived earlier. Both methods result in an ellipsoid of a = 6378.144 km and 1/f = 298.234. The parameters of the initial (Kaula) ellipsoid were a = 6378.165 km and 1/f = 298.300. The semimajor axis of the adapted ellipsoid is thus twentyone meters smaller than that of the Kaula ellipsoid. Due to the increase in flattening of the new ellipsoid over the Kaula ellipsoid, the separation of the two ellipsoids amounts to only five meters at the poles. (Author)
Descriptors : (*GEODESICS, ELLIPSOIDS)
Subject Categories : Geodesy
Distribution Statement : APPROVED FOR PUBLIC RELEASE