Accession Number : AD0807391

Title :   AN INVESTIGATION OF FACTORS WHICH DEGRADE PHASE ACCURACY IN A VLF RELATIVE NAVIGATION SYSTEM.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : McKay, John Douglas ; Preston, Gerry Lee

Report Date : DEC 1966

Pagination or Media Count : 130

Abstract : A VLF relative navigation system makes use of the fact that, at any given point on the earth, phase delay of a received VLF signal is highly stable and predictable. As the receiver is physically moved, phase delay changes linearly with distance from the transmitting station, so that by keeping track of the phase delay of the received signal from several VLF stations, one may keep an accurate plot of geographical position. Two problems experienced in measuring phase delay are the diurnal shift and long path interference. An investigation is made into a method of predicting the diurnal phase shift and the resultant phase due to simultaneous reception of long and short path signals. Also investigated is a receiving antenna having a cardioid shaped radiation pattern which could provide discrimination against long path signals. (Author)

Descriptors :   *HYPERBOLIC NAVIGATION, *RADIO TRANSMISSION, *RADIO INTERFERENCE, PHASE SHIFT CIRCUITS, LOOP ANTENNAS, PREDICTIONS, THESES, VERY LOW FREQUENCY, DIURNAL VARIATIONS, INFORMATION THEORY, ATTENUATION, PHASE DISTORTION, COMPUTER PROGRAMS, BIBLIOGRAPHIES, RADIO RECEIVERS.

Subject Categories : Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE