Localization and Dynamics Determinations Over Spherical Surfaces
Abstract
Algorithms providing the location and dynamics (course and speed) of a moving vehicle are derived for application to navigation and localization systems on a global basis. The basic measures, used for computing the location and vehicle dynamics, are obtained from signals propagated over great-circle paths between the vehicle in question and two (or more) pairs of receiving sensors. The measured signal parameters are the time register (or time delay) and the time scale-factor (or doppler) shift, between pairs of receiving sensors. Algorithms and graphs are presented to further provide the resolution in localization and vehicle dynamics achievable for any given system geometry. These resolution (or error) data are given in terms of the resolution in the basic measures of time register and time scale-factor shift. The central idea of the report is to provide, in convenient and usable form, algorithms and data which yield on a global-system basis the location and the dynamics of a transiting vehicle and the confidence limits for these parameters. Examples are provided for both electromagnetic signal propagations and underwater acoustic propagations to illustrate the feasibility and broad applicability of the resulting data. Optimum and near optimum system geometries are derived for both a worldwide global navigation system and for a more limited surveillance area. The results indicate that a high degree of resolution in both localization and dynamics is achievable over extremely long ranges, provided reliable propagation conditions exist. An interesting aspect of the spherical geometry is that it provides a natural propagation convergence zone on the opposite side of the globe from the signal source.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1975
- Accession Number
- ADA013214
Entities
People
- Albert A. Gerlach
Organizations
- United States Naval Research Laboratory