A STUDY OF FACTORS AFFECTING THE ACCURACY OF POSITION FIX FOR LUNAR TRAJECTORIES

摘要

The accuracy of the position fix as obtained from simultaneous onboard optical measurements is discussed with respect to the gradients of the measurements. Equations for the gradients of various types of measurements in position fixing are discussed. An approximate method for predicting the error ellipsoid for a position-fixing system is given. The position errors are illustrated by application of the results to a lunar trajectory.