A Simple Preprocessor for Narrowband Omega Retransmission

Abstract

Global distress location and search and rescue operation may utilize Omega VLF navigation signals for position determination. The rescue radio would retransmit the Omega signals to a satellite for relay to a search and rescue center, where the position of the retransmitter would be determined. Since only the phases of the Omega signal are required, preprocessing prior to retransmission can have several advantages, including reduced bandwidth, transmission ti.me, transmitter power, antenna size, and error rate. Both phase measurement and averaging can be accomplished by a simple counting phase detector. The characteristics of an Omega preprocessor using a set of counting detectors are described.