Accession Number : AD0780944
Title : Optimum Position Estimation for Omega.
Descriptive Note : Doctoral thesis,
Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA
Personal Author(s) : Waylan, Cecil Jerome
Report Date : JUN 1974
Pagination or Media Count : 194
Abstract : Omega is a worldwide VLF navigation system which uses phase differencing techniques. The VLF signals of Omega are perturbed by phase uncertainties caused by factors such as diurnal effects which are quite predictable and other factors which are not so predictable. This dissertation models the effective phase velocity uncertainties which result from the less predictable phase uncertainties as jointly Gaussian perturbations to the phase velocities. This approach of modeling VLF propagation for Omega has not previously been taken. The more predictable factors are incorporated into determination of the mean values of the phase velocities. This model allows any interfrequency and interstation correlation to the phase disturbances of Omega to be readily taken advantage of to improve the estimation performance. From this model, the maximum likelihood position estimation equations are derived for Omega with an arbitrary number of frequencies. (Modified author abstract)
Descriptors : *HYPERBOLIC NAVIGATION, VERY LOW FREQUENCY, MATHEMATICAL MODELS, PHASE, VELOCITY, VARIATIONS, POSITION FINDING, OPTIMIZATION, MONTE CARLO METHOD, THESES.
Subject Categories : Air Navigation and Guidance
Distribution Statement : APPROVED FOR PUBLIC RELEASE