University of Bath: Ascension Island Skiymet Meteor Radar data (2005-2012)

The University of Bath's Ascension Island meteor radar (7.9 S, 14.4 W) is an all-sky VHF (Very High Frequency) meteor radar commercially produced Skiymet system. The system was operational from October 2001 to June 2011, albeit with some gaps in the data coverage, in support of a number of research projects - see linked Project records for further details. Meteor detection and derived wind data from this instrument were collected in support of a number of research projects - see linked Project records for further details. The radar detects radio scatter from the ionised trails of individual meteors drifting with the winds of the upper mesosphere, mesopause and lower thermosphere. A low-gain transmitter antenna is used to provide broad illumination of the sky. An array of five receiver antennas act as an interferometer to determine the azimuth and zenith angles of individual meteor echoes. Doppler measurements from each meteor determine the radial drift velocity and the meteor is assumed to be a passive tracer of atmospheric flow. The radar typically detects of order a few thousand meteors per day. These observations can be used to determine zonal and meridional winds in the mesosphere, mesopause and lower thermosphere at heights of about 80 – 100 km and with height and time resolutions of ~ 3 km and 2 hours. The radar produces daily “meteor position data” data files (mpd files) recording the details of each individual meteor echo. In normal operation a few thousand individual meteors are detected per day. See parameter list for details of available data. Recordings are made for each individual meteor detected allowing measurements of zonal and meridional wind speeds in the mesosphere and lower thermosphere to be obtained. Meteor count rates vary diurnally and with season, but are usually up to a few thousand meteors per day.