On the topographic bias in geoid determination by the external gravity field |
| |
| Authors: | Lars E Sjöberg |
| |
| Institution: | (1) Division of Geodesy, Royal Institute of Technology, 100 44 Stockholm, Sweden |
| |
| Abstract: | The topographic bias is defined as the error/bias committed by continuing the external gravity field inside the topographic
masses by a harmonic function. We study the topographic bias given by a digital terrain model defined by a spherical template,
and we show that the topographic bias is given only by the potential of an inner-zone cap, and it equals the bias of the Bouguer
shell, independent of the size of the cap. Then we study the effect on the real Earth by decomposing its topography into a
template, and we show also in this case that the topographic bias is that of the Bouguer shell, independent of the shape of
the terrain. Finally, we show that the topographic potential of the terrain at the geoid can be determined to any precision
by a Taylor expansion outside the Earth’s surface. The last statement is demonstrated by a Taylor expansion to fourth order. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
