ERROR ANALYSIS OF SEVERAL METHODS OF DETERMINING VEHICLE POSITION IN EARTH-MOON SPACE FROM SIMULTANEOUS ONBOARD OPTICAL MEASUREMENTS

摘要

The relative accuracies of seven methods of navigating in earth-moon space were determined from a statistical analysis. Each of the first five methods is based on a different combination of simultaneous onboard optical sightings of a near body (earth or moon), the sixth incorporates a body-based radar-distance measurement, and the seventh is based on two-body measurements (earth and moon). The types of optical sightings include measurements of body angular diameter, declination and right ascension of a body, and angles between lines of sight to stars and near bodies.nWith the use of the Monte Carlo technique, random uncorrelated errors were considered to exist in each of the measurements required to determine a position fix. The measurement errors were assumed to be normally distributed and some realistic values were specified for the standard deviations of error in the dif¬ferent types of measurements.