An Overlap Comparison Using a Batch Filter with the Statistical Orbit Determination I Project

In this study, a comparison of solutions for tracking data from the term project obtained by using two different overlapping sets of range and range rate data was completed. The original data file contained 385 points over a time period of 18,340 seconds, or approximately 5 hours. This data was divided into two parts with some overlapping data points. The first data set covered the time period from the initial time to 12,600 seconds, which resulted in a data file with 288 points. The second data set began at 5,400 seconds and continued until the end of the data, giving a data file with 297 points. In both cases, several passes through the batch filter were used to generate a best estimate for the state and the covariance at the time that the corresponding data set started. The trajectory was then integrated forward and the covariance was mapped to the desired time using the equation ( ) ( ) o k o o k k t , t Φ P t , t Φ P = . A comparison was desired during the overlap time period between 1.5 and 3.5 hours, so plots were generated with one standard deviation (1σ) magnitudes from P ± k, and the differences in the solution overlaps for this period. They are given in the RIC (radial, in-track, cross-track) coordinate system in Figure 1. The equations for converting the state and covariance matrix from the ECI to RIC frame are given in section 4.16.1 of the class text.