OPTIMUM INTERPOLATION INTERVAL AND ORDER IN SATELLITE EPHEMERIDES.
NAVAL WEAPONS LAB DAHLGREN VA
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This study was undertaken to provide source data from which optimum interpolation intervals and orders could be selected for use in geodetic solutions. In order to maintain a maximum interpolation error of approximately 0.1 meter in the coordinates, an optimum interpolation interval of 240 seconds at 10th or 12th order was selected for the 500 nautical mile altitude satellite, an interval of 120 seconds at 8th order for the 100 n.m. altitude satellite, and an interval of 1440 seconds at 8th order for the 11,000 n.m. altitude satellite. A reduction of interpolation accuracy occurs when the interpolation interval is increased or the order of interpolation decreased. Due to the contribution of non-Keplerian gravity field terms to interpolation errors, the errors are attributed to orbit perturbations rather than to the central gravitational term. Results from comparisons of velocity errors obtained from differentiated interpolated coordinates with those obtained from interpolated velocities show greater accuracy in the differentiated velocities. Timing studies provide a basis for minimizing computer time usage when a large number of interpolations are performed for a large set of functions and derivatives. Author
- Unmanned Spacecraft
- Spacecraft Trajectories and Reentry