Three solution techniques for the orbital intercept problem including oblateness effects
Three methods for solving the orbital intercept problem in the presence of an oblate earth are presented. Both iterative and direct approaches for solving the problem were compared in the bases of computational time and relative accuracy of the results.
The two iterative methods were found to agree to eight significant figures for all elliptic intercept orbits studied. The results obtained from the direct approach were found to agree with the iterative methods's results to eight significant figures for low intercept eccentricities ( e < 0.2), and to five significant figures for high intercept orbit eccentricities (e = 0.9). However, the direct method was found to be twice as fast, computationally, as either of the two iterative methods. The iterative methods each take essentially the same amount of computational time.
Neither type of routine yields accurate results for half-revolution intercept and hyperbolic intercept orbits. The method for developing these procedures, the computer code implementing the methods, and selected results are included.