Reduced-Kinematic POD

Abstract

Here we present the results of reduced-kinematic POD, as introduced and published in Švehla and Rothacher (2005). Reduced-kinematic POD can be defined as the fourth fundamental approach in precise orbit determination, along with kinematic, reduced-dynamic and dynamic POD. The main difference between reduced-kinematic and reduced-dynamic orbit determination is that in the reduced-kinematic POD the constrained normal equations are set up for the epoch-wise kinematic positions (with epoch-wise clock parameters), whereas in the reduced-dynamic approach, dynamic parameters (such as initial Keplerian state vector, aerodynamic drag coefficients, empirical accelerations, etc.) and/or some pseudo-stochastic parameters are determined. Thus, in the case of reduced-kinematic POD, degrees of freedom are reduced towards a dynamic orbit, whereas in the reduced-dynamic orbit, the dynamics of the orbit is reduced towards a kinematic orbit. Due to the relative or absolute constraints that are used in the reduced-kinematic POD, we did not use nor develop this approach further for LEO satellites. We merely present typical results for the sake of completeness.