The method of least squares collocation is used to estimate the accuracy and correlation of 1 degree x 1 degree anomalies that could be determined from a high-low satellite to satellite tracking mission. The observed data is taken to be the line of sight acceleration which can be computed from the range rate data. Variables considered in this study were: (a) the spherical distance from the center of the 1 degree x 1 degree block within which data is selected for use; (b) the accuracy of the 'observed' accelerations; (c) the height of the low satellite; and (d) the data density or interval. Typical results indicate that a low satellite height of 200 km, a data noise corresponding to a range accuracy of + or - 0.015 cm/sec, would yield a 1 degree x 1 degree anomaly to an accuracy of about + or - 8 mgals with an average error correlation coefficient between adjacent blocks of -0.6. Lowering the satellite to 150 km reduces the accuracy to about + or - 5 mgals but increases the correlaton to about -0.9. This study does not consider the effects of orbit error, nor errors in the degree 12 reference field. In addition, some results could not be obtained when stable matrix inversions could not be obtained. This occured when dense data and/or low data noise was being used.
Interim Report Ohio State Univ
- Pub Date:
- September 1979
- Gravity Anomalies;
- Least Squares Method;
- Satellite-To-Satellite Tracking;
- Launch Vehicles and Space Vehicles