Universal Journal of Communications and Network 1(1): 32-37, 2013 http://www.hrpub.org DOI: 10.13189/ujcn.2013.010106 Elevation Variation with Low Earth Orbiting Search and Rescue Satellites for the Station Implemented in Kosovo Shkelzen Cakaj Post and Telecommunication of Kosovo, Prishtina, Kosovo Faculty of Electrical and Computing Engineering, University of Prishtina, Kosovo *Corresponding Author: shkelzen.cakaj@fulbrightmail.org Copyright © 2013 Horizon Research Publishing All rights reserved. Abstract NOAA’s (National Oceanic and Atmospheric Administration) - LEO (Low Earth Orbit) environmental satellites provide continuous coverage of Earth, supplying high-resolution global meteorological, oceanic and space observation data what are too important in aerospace and maritime. In addition, these satellites are part of the international Search and Rescue Satellite Aided Tracking (SARSAT) system. SARSAT is a satellite system designed to provide distress alert and location data in order to assist on search and rescue operation. The position of the satellite within its orbit considered from the ground station point of view is defined by Azimuth and Elevation angles. There is a direct relationship between communication duration and maximal elevation. Higher maximal elevation provides longer communication between the satellite and a Local User Terminal (LUT). Longer communication provides more Doppler events providing higher accuracy on location determination. Passes with too short communication duration, consequently with no data provided are considered as missed passes. Under assumption that the LUT is implemented in Kosovo, it is simulated the variation of elevation for different orbits for a period of one month. Simulation about elevation variations, among SARSAT satellites and local user terminal dedicated for search and rescue services is provided through this paper. Keywords Satellite, Elevation, LUT, Communication 1. Introduction COSPAS-SARSAT is an international, humanitarian satellite based search and rescue system which operates continuously, detecting and locating transmissions from emergency beacons carried by ships, aircrafts and individuals. The USA segment is referred to as SARSAT (Search and Rescue Satellite Aided Tracking) system. In cases of aircraft, marine or individual distress the location determination accuracy and the time required to alert rescue authorities depends on the communication reliability between the LUTs and satellites [1- 3]. SARSAT system detects and locates distress beacons (406MHz) activated at distress location. System calculates the location of distress event using Doppler processing techniques. Processed data are on-board stored and repeatedly retransmitted to Local User Terminals (LUT) when they are visible as the satellite orbits the Earth. Each satellite pass transmits information about distress location. There is a clear relationship between communication duration and maximal elevation [4-5]. This paper aims through simulation to record the maximal elevation variations for different satellite orbits at local user terminal assumed to be implemented in Kosovo. Considering these variations in elevation can be concluded about the horizon mask at the point of local user terminal implemented. The paper describes the general concept of search and rescue system followed by a brief satellite’s tracking. Finally, the simulation elevation concept and respective results are provided. Simulation relates to SARSAT satellites. 2. COSPAS-SARSAT Concept The basic COSPAS - SARSAT concept is illustrated in Figure 1 [6], [7]. Figure 1. COPSAS-SARSAT concept