Articles | Volume 23, issue 7
Ann. Geophys., 23, 2357–2368, 2005

Special issue: SEEK-2 (Sporadic-E Experiment over Kyushu 2)

Ann. Geophys., 23, 2357–2368, 2005

  13 Oct 2005

13 Oct 2005

Radio tomographic imaging of sporadic-E layers during SEEK-2

P. A. Bernhardt1, C. A. Selcher2, C. Siefring1, M. Wilkens3, C. Compton4, G. Bust5, M. Yamamoto6, S. Fukao6, O. Takayuki7, M. Wakabayashi7, and H. Mori8 P. A. Bernhardt et al.
  • 1Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375, USA
  • 2Information Technology Division, Naval Research Laboratory, Washington, DC 20375, USA
  • 3Icarus Research, Inc., Bethesda, MD, USA
  • 4West Virginia University, Morgantown, WV, USA
  • 5Applied Research Laboratory, University of Texas Austin, Austin, TX, USA
  • 6Radio Science Center for Space and Atmosphere, Kyoto University, Kyoto, Japan
  • 7Graduate School of Science, Tohoku University, Japan
  • 8Communications Research Laboratory, Tokyo, Japan

Abstract. During the SEEK-2 Rocket Campaign in August 2002, a Dual Band Beacon (DBB) transmitting to Ground Receivers provided unique data on E-Region electron densities. Information from two rocket beacons and four ground receivers yielded multiple samples of E-region horizontal and vertical variations. The radio beacon measurements were made at four sites (Uchinoura, Tarumizu, Tanegashima, Takazaki) in Japan for two rockets (S310-31 and S310-32) launched by the Institute of Space and Aeronautical Science (ISAS). Analysis was completed for four sets of beacon data to provide electron density images of sporadic-E layers. Signals from the two-frequency beacons on the SEEK-2 rockets were processed to yield total electron content (TEC) data that was converted into electron density measurements. Wide variations in layer structures were detected. These included horizontal sporadic-E variations, vertical profiles of double, single, and weak layers. The radio beacon measurements were shown to be in agreement with the in-situ SEEK-2 sensors. The first tomographic image of a sporadic-E layer was produced from the data. The rocket beacon technique was shown to be an excellent tool to study sporadic-E layers because absolute TEC accuracy of 0.01 TEC Units can be easily obtained and, with proper receiver placement, electron density images can be produced using computerized ionospheric tomography with better than 1km horizontal and vertical resolution.

Keywords. Ionospheric irregularities – Instruments and techniques – Mid-latitude ionosphere