Determination of the Gravity Disturbance by Processing the Gravity Gradiometer Surveying System - Processing Procedure and Results.

摘要

The gravity gradiometer surveying system (GGSS) took the first flight in the Texas/Oklahoma area and the data were released in April, 1989. The main problem of processing the GGSS gradient data is that there is bias in the data. If the tie point values of the gravity gradient are available, then the bias can be removed from the GGSS gradient data by using crossover discrepancy adjustment. Since there are no tie point values of the gravity gradient, the free-air gravity anomaly was used as the tie point values. Two components of the GGSS gradient data T sub xz and T sub yz were integrated linearly into the vertical derivatives of the disturbing potential l sub z, the bias and tilt in the T sub z for each track were removed by combining the tie point values of the free-air anomaly in the test area. Finally, the T sub z was recovered on the ground by using the fast Fourier transformation and least squares collocation. The results were compared with the free-air anomalies in the test area. The difference between the T sub z and the free-air anomaly has the root mean square value 5.8 mgal. This result is reasonable in comparison with the accuracy + or - 10 E of the GGSS gradient data. A crossover discrepancy analysis indicated that the GGSS gradient data could have the accuracy about 10 Eotvos. (jhd)