Mark Hinga, USAF AFMC AFRL/RDST
Keywords: Angles only, co-planar, stabilize
Abstract:
Orbital trajectory estimation and refinement is a pressing issue within the national security and civilian space domain. Space debris and uncorrelated tracks (UCT) all require accurate observation and trajectory estimation to prevent potentially catastrophic collisions. The numbers and types of observers able to make measurements on these tracks are constrained, so utilizing a singular observer to refine an object trajectory (rather than multiple observers) would benefit a host of applications.
Many of the existing state-of-the-art orbit determination applications are geared towards ground-based assets and do not solve the problem of co-planar geometries and Geosynchronous Transfer Orbits (GTOs). Assumptions for these existing applications require an assumed orbit class. For this investigation, an improved orbit determination (OD) algorithm will be designed which will mitigate the co-planar singularity problem without the need of an a priori assumption of either orbit class or any orbit-specific orbital regime.
What is novel in this approach is the application of a least squares batch initial state estimator that implements the linearized perturbation technique (fixed and free final time guidance) in conjunction with a Lambert solver and a stabilized Gaussian-IOD technique (to handle the co-planar singularity condition as low as 0.01 deg) to initialize an EKF enabling it to keep hold of the unique stabilized solution. This stabilized batch algorithm allows for accurate initial orbit estimation with a single observer using a limited set of (at least 6) measurements and is built upon a system of co-planar observed singularity conditions that form the normal equations of the exact values of the f and g series least squares solution.
Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525.
Date of Conference: September 11-14, 2018
Track: Astrodynamics