ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-4-649-2004 The EISCAT meteor-head method – a review and recent observations Pellinen-Wannberg A. 1 Swedish Institute of Space Physics, Kiruna, Sweden 21 04 2004 4 3 649 655 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/4/649/2004/acp-4-649-2004.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/4/649/2004/acp-4-649-2004.pdf

Since the very first meteor observations at EISCAT in December 1990, the experimental method has improved significantly. This is due to a better understanding of the phenomenon and a recent major upgrade of the EISCAT signal processing and data storage capabilities. Now the simultaneous spatial-time resolution is under 100 m-ms class. To illuminate the meteor target for as long as possible and simultaneously get as good altitude resolution as possible, various coding techniques have been used, such as Barker codes and random codes with extremely low side lobe effects. This paper presents some background and the current view of the meteor head echo process at EISCAT as well as the observations which support this view, such as altitude distributions, dual-frequency target sizes and vector velocities. It also presents some preliminary results from recent very high resolution tristatic observations.