Abstract
The real-time trajectory estimation of the lowest-flying earth satellite by a square root filter is discussed in this paper. A perigee altitude of this satellite, which is attained by firing an on-off capable solid rocket motor, is 100∼150km, therefore a real-time trajectory estimation is required for monitoring the altitude.
This filter is a non-linear square root filter which uses tracking radar data of an earth station and is designed to suppress to a minimum the divergence in filtering by a special device. The capability of this filter is examined by a precise simulation program.
As a result of the simulation, it is shown that the estimation error of perigee altitude is less than 1km and the computation time of this filter suits to a real-time operation.
