RANGE-ONLY INITIAL ORBIT DETERMINATION

摘要

Range-only initial orbit determination (IOD) is designed to derive six-dimensionalorbit estimates from range measurements, their time-tags, and sensor locations.Accurate range-rate interpolants are derived from range measurementswith a new interpolation algorithm that couples Lagrange and Chebyshevinterpolators. The IOD measurement set thus consists of range measurementsand range-rate interpolants. Reduction from the six dimensional orbit problemto a three dimensional problem is enabled with the use of Lagrange's f and gexpressions as developed by Herrick in closed form. A new three-dimensionalsearch algorithm calculates multiple six-dimensional orbit estimates usingtwo-body dynamics. The number of solutions was found to be inversely proportionalto the size of range measurement component thermal noise SigmaσW. Each two-body orbit estimate is used to seed an iterative nonlinear leastsquares orbit determination with full force model. Iterative convergence definessuccess for the range-only IOD estimate used.