ATMOSPHERIC DENSITY CORRECTION USING TWO LINE ELEMENT SETS AS THE OBSERVATION DATA

摘要

Corrections to the GOST Atmosphere Density Model are derived from the Two Line Element (TLE) set data. The density correction includes a bias term and a term that is linear with the altitude. Density corrections are constructed on a one day grid. The input to the construction process is the daily TLE sets for between 300 to 500 drag-perturbed space objects and the observed solar flux and the geomagnetic data. Each of the TLE is converted to a 'noisy' single-averaged element set by adding the long period perturbations. Then several 'noisy' single-averaged element sets are least-squares fit with the USM semianalytical satellite theory with the GOST density model. This results in a smoothed USM element set and associated ballistic factor. The density corrections are generated from the smoothed ballistic factors resulting from the secondary data processing. The secondary data processing is repeated with the corrected GOST density model. The fit and predict results with the uncorrected and corrected density models are compared. The process is demonstrated over a 10-month interval from April 2002 through January 2003. The ballistic factor for the Starshine 3 spherical satellite with the iterated secondary processing closely matches the theoretical value.