Tracking Storms in the Ionosphere

Scott M. Elder and Michael H. Elder

Abstract:	When Radio Frequency (RF) travels through the Ionosphere, the signal transmission time is delayed due to storms in the ionosphere. The amount of signal delay directly is correlated to the intensity of the storm in the Ionosphere. The Global Positioning System (GPS) is a constellation of 24 satellites which transmit RF signals used for navigation through the Ionosphere to earth. GPS position data supplies latitude and longitude position data as well as altitude data. The altitude data is the most sensitive data and is the one most affected by storms in the ionosphere. For my experiment, I collected GPS altitude measurement data with my GPS receiver over a one month period. The time of my measurements was adjusted 4 minutes each day to always have the same GPS satellite constellation configuration. This eliminated any position error due to constellation DOP. To determine my true altitude, I used a WAAS capable receiver to determine an altitude which was not affected by any ionospheric storms. The WAAS corrections remove most of the position error affect from the Ionosphere and this altitude was used as my zero error altitude. I compared my one month of GPS altitude measurement data with the Space Environment Center (SEC) Ionosphere storm data to build a chart that I could use to determine ionosphere storm presence and intensity. This chart compared my altitude error measurements (not WAAS corrected) with the SEC data for Ionosphere storm intensity. The result was a graphical comparison matching my altitude error data to the SEC Ionosphere storm data. The graph related Kp storm values to errors in my altitude measurements. After my graph was completed, I then made some random position (altitude) measurements to determine if I could now track a storm in the Ionosphere and determine storm intensity. During one of my sample measurements, I determined from the amount of error in the GPS altitude measurement that there was a storm in progress in the ionosphere. I took several readings over the next five hours and analyzed the data to determine the storm intensity. The next day, when the SEC data was available, I compared my analyzed readings with the SEC ionosphere storm readings. There was a storm in the ionosphere according to the SEC WEB site and my graphical results did compare with the storm Kp levels listed by SEC. My project conclusion is that storms can be tracked in the Ionosphere and the storm intensity estimated by using GPS altitude position error.
Published in:	Proceedings of the 2005 National Technical Meeting of The Institute of Navigation January 24 - 26, 2005 The Catamaran Resort Hotel San Diego, CA
Pages:	735 - 740
Cite this article:	Elder, Scott M., Elder, Michael H., "Tracking Storms in the Ionosphere," Proceedings of the 2005 National Technical Meeting of The Institute of Navigation, San Diego, CA, January 2005, pp. 735-740.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In