An Initial Orbit Determination Method Using Single-Site Very Short Arc Radar Observations

A new initial orbit determination (IOD) method using single-site very short arc radar observations is proposed. The method uses slant range, azimuth, and elevation angles to determine the position vector and uses higher order radial measurements (velocity, acceleration, and jerk) to determine the velocity vector. The IOD accuracy based on the geometric dilution of precision (GDOP) metric is analyzed using a linearization approach. Relations between the GDOP and the observation geometry are investigated under a near-circular constraint and the optimal observation geometry for determining the velocity vector is identified. Monte Carlo simulations are presented for a typical low-Earth orbit satellite under two observation geometry configurations. The results demonstrate that the proposed method is feasible for very short arc initial orbit determination.