On the realization of a 10 cm relative oceanic geoid
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Date
1976-11
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University. Division of Geodetic Science
Abstract
An investigation into the theoretical and numerical problems associated with the computation of a 10 cm relative oceanic geoid was carried out. Based on a model which requires potential coefficients and gravity anomaly information for the computation of geoidal undulations, an error analysis was developed through which the necessary data requirements for the realization of such a high accuracy geoid were derived. In order to ensure the validity of the Stokes integral to the required level of accuracy, seasonal and latitude dependent atmospheric corrections to the gravity and height anomalies were developed. From these corrections it was deduced that when the combined latitudinal/ seasonal dependence is neglected, the maximum error introduced is of the order of 40 μgals for the gravity corrections and 0.7 cm for the height anomaly corrections. While attempting the error analysis in a more or less rigorous manner, the numerical difficulties associated with such an approach were brought to light. An approximate error model in the frequency domain was then developed through which an idea was obtained as to the nature, quality and quantity of the desired data requirements. Various data sets could result in a 10 cm relative oceanic geoid. One such set, indicative of the strictness of these requirements, involves gravity profile spacings of approximately 3 km with observational noise not exceeding 0.5 mgals inside detailed data caps of 30°, and potential coefficients available to degree and order 70.
Description
Prepared for National Aeronautics and Space Administration, Goddard Space Flight Center, Greenbelt, Maryland: Grant No. NGR 36-008-161, OSURF Project No. 3210