caa a22 4500 475737547 CHVBK 20180406123450.0 cr unu---uuuuu 170329e20001101xx s 000 0 eng 10.1007/s001900000112 doi (NATIONALLICENCE)springer-10.1007/s001900000112 Haagmans R. Department of Mapping Sciences, The Agricultural University of Norway, PO Box 5034, N-1432 Ås, Norway e-mail: roger.haagmans@ikf.nlh.no; Tel.:+47 64948846; Fax: +47 64948856, NO aut A synthetic Earth for use in geodesy [Elektronische Daten] [R. Haagmans] Abstract.:  A synthetic Earth and its gravity field that can be represented at different resolutions for testing and comparing existing and new methods used for global gravity-field determination are created. Both the boundary and boundary values of the gravity potential can be generated. The approach chosen also allows observables to be generated at aircraft flight height or at satellite altitude. The generation of the synthetic Earth shape (SES) and gravity-field quantities is based upon spherical harmonic expansions of the isostatically compensated equivalent rock topography and the EGM96 global geopotential model. Spherical harmonic models are developed for both the synthetic Earth topography (SET) and the synthetic Earth potential (SEP) up to degree and order 2160 corresponding to a 5′×5′ resolution. Various sets of SET, SES and SEP with boundary geometry and boundary values at different resolutions can be generated using low-pass filters applied to the expansions. The representation is achieved in point sets based upon refined triangulation of a octahedral geometry projected onto the chosen reference ellipsoid. The filter cut-offs relate to the sampling pattern in order to avoid aliasing effects. Examples of the SET and its gravity field are shown for a resolution with a Nyquist sampling rate of 8.27 degrees. Springer-Verlag Berlin Heidelberg, 2000 Key words: Gravity field - Synthetic Earth - Boundary values nationallicence https://doi.org/10.1007/s001900000112 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s001900000112 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Haagmans R. Department of Mapping Sciences, The Agricultural University of Norway, PO Box 5034, N-1432 Ås, Norway e-mail: roger.haagmans@ikf.nlh.no; Tel.:+47 64948846; Fax: +47 64948856, NO aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer