Comparison of Ray Tracing Through Ionospheric Models

<p>A comparison of ray tracing predictions for transionospheric electromagnetic wave refraction and group delays through ionospheric models is presented. Impacted applications include over-the-horizon RADAR high frequency communications direction finding and satellite communications. The ionospheric models used are version 2.1 of Utah State University's Global Assimilation of Ionospheric Measurements (USU GAIM) model and the 2001 version of the International Reference Ionosphere (IRI) model. In order to provide ray tracing results applicable to satellite communications for satellites at geosynchronous orbit (GEO) a third ionospheric model is used to extend the sub-2000-km USU GAIM and IRI ionospheric specifications to 36540 km in altitude. The third model is based on an assumption of diffusive equilibrium for ion species above 2000 km. The ray-tracing code used is an updated implementation of the Jones-Stephenson ray-tracing algorithm provided by L. J. Nickisch and Mark A. Hausman. Ray-tracing predictions of signal refraction and group delay are given for paths between Goldstone Deep Space Observatory near Barstow California and the PanAmSat Galaxy 1R satellite. Results are given for varying frequency between 11MHz to 1GHz varying time of day between 0600 and 1700 Pacific Standard Time on 1 November 2004 and varying signal transmission elevation angle.</p><p>This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact and remains as true to the original work as possible. Therefore you will see the original copyright references library stamps (as most of these works have been housed in our most important libraries around the world) and other notations in the work.</p><p>This work is in the public domain in the United States of America and possibly other nations. Within the United States you may freely copy and distribute this work as no entity (individual or corporate) has a copyright on the body of the work.</p><p>As a reproduction of a historical artifact this work may contain missing or blurred pages poor pictures errant marks etc. Scholars believe and we concur that this work is important enough to be preserved reproduced and made generally available to the public. We appreciate your support of the preservation process and thank you for being an important part of keeping this knowledge alive and relevant.</p><br>