Application of optical tracking and orbit estimation to satellite orbit tomography

Satellite orbit tomography is shown through numerical simulations to reconstruct the spatially-resolved global neutral density field using only a single ground site. The study assumes a ground site located near Los Alamos, New Mexico, and selects nearly 200 resident space objects in low-Earth orbit as potential tracking targets. Over a chosen six-day time span in 2011, around 50 objects have enough visibilities to be used. A Constrained Admissible Region Multiple Hypothesis Filter (CAR-MHF) is tested for estimating the satellite position, velocity, and drag ballistic coefficients. The CAR-MHF has difficulty estimating the state in these simulations when the assumed density model has large discrepancies compared with the truth model; however, the simulation results provide reasonable estimates of the expected orbit estimation accuracy for the chosen system. Using this information, the tomography is simulated for the remaining objects, and the density field at lower altitudes around 412 km is reconstructed to within several percent of the true time-averaged density values.