The Global Rescue Alarm Net (GRAN): a system analysis.

Abstract

The Global Rescue Alarm Net (GRAN) is a proposed Search and Rescue (SAR) system. The purpose of the system is to provide real-time worldwide distress alarm, identification, and position information for the isolated distress case„ In the GRAN system a link consists of a handheld Search and Rescue Communicator (SARCOM) unit, a geosynchronous Search and Rescue Satellite (SARSAT) relay, and a processing station, the Search and Rescue Central (SARCEN). This thesis is a system analysis of the proposed GRAN system to generate the broad system requirements. To provide global coverage the numbers and locations of SARSATs and SARCENs are determined. Based on SAR statistical data, SARCOM distribution, multiple access, and probability of interfering transmissions are examined. The SARSAT characteristics such as configuration, antenna gains, and power output are considered in relation to the overall system.- From experimental and theoretical data, reference values are chosen which are representative of near-worst case from which the total link can be characterized. From this characterization, system parameters such as SARCEN G/T and SARSAT transmit power can be determined.