Elsie  A program for optimal trajectory estimation
Abstract
A description is presented of Elsie, a Kalman filter used in the postflight analysis of missile test flight data. The main purpose of the program is to produce a file containing time versus position and velocity, which represents the optimal combination of all the data. Such a filter is needed because small modeling errors and noise in the data can produce large errors in the trajectory. An outline is provided of the mathematical basis of the program. Elsie runs in conjunction with a group of programs known as the Eye of the Beholder. These programs transform Elsie's trajectory into various coordinate frames of interest to different users.
 Publication:

Summer Computer Simulation Conference
 Pub Date:
 1981
 Bibcode:
 1981cosi.conf..261D
 Keywords:

 Computer Programs;
 Flight Simulation;
 Missile Trajectories;
 Parameter Identification;
 Postflight Analysis;
 Trajectory Optimization;
 Computerized Simulation;
 Error Analysis;
 Kalman Filters;
 Missile Tests;
 Position Errors;
 Trajectory Analysis;
 Velocity Errors;
 Space Communications, Spacecraft Communications, Command and Tracking