Error Distributions of Best Estimate of Position from Multiple Time Difference Hyperbolic Networks

A mathematical model for the error distribution of the best estimate of position of a vehicle as determined from a set of simultaneous measurements of times of arrival of electromagnetic waves from an arbitrary number of ground stations is obtained. The major and minor axes of the error ellipse, as well as the angle that they make with the assumed axes, are determined. The results are in such form as to be easily adaptable for use with a computer.