Often, a radar measures targets by their distance, or range, from the radar. A method for viewing these measurements is a Range Time plot, which plots the ranges of targets vs. time. When radar tracks objects whose Range Time tracks cross, it is sometimes uncertain which track belongs to which target. The crossings themselves are called "odd" if the tracks cross straight through each other, forming an "X", or are called "even" if the tracks approach each other and then diverge. It was studied how often these different crossings occur due to objects separating in space. An analysis of the situation where an object splits into n objects led to the conclusion that all crossings were odd. If these n splits occur sequentially, however, even crossings were possible, but turned out to be extremely rare in a Monte Carlo simulation. Statistics about the odd crossings of this simulation were aggregated for their frequency, crossing angle, and crossing time. In addition, it was examined how well targets could be tracked through an individual crossing. An algorithm was devised to track targets through crossings using only data from Range Time plots, i.e. data about the targets" ranges over time. The performance of this algorithm was tested with a large set of Monte Carlo simulations. Another, smaller set, of Monte Carlo simulations were generated, and those for which this algorithm could not give an answer with certainty were re-analyzed by a human in a series of blinded tests, using data from a Range Doppler plot, i.e. data about the targets" range and radial velocity over time. It was determined that the performance of both tests increased as the targets" relative radial velocities and track times increased.-3-Statement of Authorship During her summer internship at MIT Lincoln Laboratory, Kathleen developed a test for evenness and oddness of Range Time track crossings for point scatterer targets, and evaluated its performance as a function of track crossing angle and length of track time. For this project, Kathleen extended the test to include dumbbell-shaped targets and evaluated its performance as a function of track crossing angle, length of track time, rate of tumble, and direction of radar line of sight. Matthew adapted a Doppler imaging algorithm written by Fannie Rogal, an MIT Lincoln Laboratory employee, during his summer internship at MIT Lincoln Laboratory. Matthew modified the code to test the minimum range separation required to discriminate two targets traveling at the same radial velocity, as a function of both targets' rates of spin, rates and angles of precession, target lengths, and radar line of sight. For this project, the code was modified to accept predetermined ballistic scenarios that led to Range Time track crossings. The script created time lapsed Range Doppler plots of the targets which were visually discriminated by a human. Alexander analyzed track crossing situations for a variety of crossing statistics. He algebraically derived crossing times for both the starburst and periodically separating ...
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