Radio Science

The Esrange MST radar: A brief introduction and procedure for range validation using balloons


  • Phillip B. Chilson,

  • Sheila Kirkwood,

  • Annika Nilsson


The Esrange VHF radar (ESRAD) is a relatively new mesosphere-stratosphere-troposphere (MST) class radar located in northern Sweden (67.88°N, 21.10°E), about 30 km east of Kiruna. The radar operates continuously and has already been included in several campaigns in which multiple profiling instruments have been used, for example, lidars, radiosondes, and scientific balloons. To intercompare the different measurements, it is essential to have precise height estimates. In this paper we begin by presenting a short technical overview of the radar. Then we describe a radar validation conducted in 1997 during a period when numerous scientific balloons were launched from Esrange. All of these balloons were tracked using one or more of the following techniques: Omega navigational system, Global Positioning System (GPS), or the Esrange C-band tracking radar (ESR). A number of these balloons passed close enough to the ESRAD beam that they could be detected by the MST radar. This unique data set has been used to check the range estimation of ESRAD. Furthermore, the data have been used to make a rough check of the geometry of the formed beam.