Non recursive digital filtering for real time trajectory estimation and instantaneous impact point prediction

Nonrecursive digital filters designed to account for random errors in tracking parameters for rocket flight are developed in the paper. Powered flight trajectory, range, altitude, position azimuth, velocity, flight path angle, and flight azimuth are determined from telemetry, and output samples of the filter are explicitly determined as a weighted sum of past and present input samples only to filter the noisy data. 10 and 20 Hz data generated from the first stage of a two stage sounding rocket are used as an example and predictions are compared with observed values. The rms errors for impact range, time, and azimuth are found to decrease with total samples. Some results were 2.4 km error for 40 samples at 10 Hz and 2.0 km for 80 samples at 20 Hz. The 40/10 data are taken as sufficient.