The use support of GPS in personnel locator system

This thesis subject is investigated as a project that is addressing a specific requirement. The Personnel Locator System (PLS), which is currently being used by Turkish Air Force, helps to locate the global position of a ejected pilot by using a special radio. The position accuracy of this current system does not meet the requirements. Radio signals are used to locate the position of the ejected pilot, which leads to a 1000 to 1500 meters of erroneous measurement. The current system equipment, which is installed on a helicopter, calculates and shows the direction and range of the signals emitted by the radio that is carried on the pilot harness. This system is not reliable due its unacceptable low accuracy. The objective of this investigation is to improve the accuracy of the system by using the Global Positioning System (GPS). A GPS receiver is mounted on the pilot carried radio and the GPS signals are transmitted on the radio signals by the DTMF codes.. The DTMF signals are received by the radio that is on the helicopter, decoded and displayed on the LCD. After this study, the position accuracy is improved comparing to the predecessor and the accurate coordinates are transferred on the radio signals. Additionally, five designated points in Diyarbakır are located using this system and the name of the locations are displayed on the LCD according to calculated coordinates. Firstly, some theoretical information is given and then the application is delineated in this study.. The GPS operating principles, serial communication rules, DTMF tone codes (encoder ? decoder), CM8870 integrated circuit, PIC 16F877 microcontroller, PIC Basic programming language are introduced in given sequence. Keywords GPS, NMEA, PLS, DTMF, Microcontroller, Serial Communication, Picbasic, Digital Communication by Radio Signals, Pilot Locator System