A Comprehensive Comparison Between Angles-Only Initial Orbit Determination Techniques

During the last two centuries many methods have been proposed to solve the angles-only initial orbit determination problem. As this problem continues to be relevant as an initial estimate is needed before high accuracy orbit determination is accomplished, it is important to perform direct comparisons among the popular methods with the aim of determining which methods are the most suitable (accuracy, robustness) for the most important orbit determination scenarios. The methods tested in this analysis were the Laplace method, the Gauss method (suing the Gibbs and Herrick-Gibbs methods to supplement), the Double R method, and the Gooding method. These were tested on a variety of scenarios and popular orbits.

A number of methods for quantifying the error have been proposed previously. Unfortunately, many of these methods can overwhelm the analyst with data. A new method is used here that has been shown in previous research by the author. The orbit error is here quantified by two new general orbit error parameters identifying the capability to capture the orbit shape and the orbit orientation.

The study concludes that for nearly all but a few cases, the Gooding method best estimates the orbit, except in the case for the polar orbit for which it depends on the observation interval whether one uses the Gooding method or the Double R method. All the methods were found to be robust with respect to noise and the initial guess (if required by the method). All the methods other than the Laplace method suffered no adverse effects when additional observation sites were used and when the observation intervals were unequal. Lastly for the case when the observer is in space, it was found that typically the Gooding method performed the best if a good estimate is known for the range, otherwise the Laplace method is generally best.