Meteor radar

Meteor radars are reliable and widespread observational tools used to investigate the neutral dynamics of the mesosphere and lower thermosphere region. These radars make use of the scattering of electromagnetic waves by the ionized gas in the meteor trails. Assuming that the measured Doppler shifts are due to the meteor trail drifting with the neutral winds present at the observed altitudes, this type of radar can provide horizontal winds between 80 and 100 km of altitude with a reasonable temporal resolution (up to 1 hour). From these winds, information on planetary waves, tides and gravity waves can be extracted by applying various mathematical methods. Meteor radar observations can also be used to estimate the temperature at mesopause altitudes by measuring the ambipolar diffusion of the meteor trails.

Conventional meteor radars consist of one transmitting antenna and a co-located receiving array of five antennas in what is usually known as a SIMO (Single Input, Multiple Output) configuration. The transmitted signal is pulsed, and the five antennas on reception are required to do interferometry and thus unambiguously determine the position of the specular point along the meteor trails. The IAP has operated such monostatic meteor radars in Andenes (northern Norway) and Juliusruh (northern Germany) until recently, when both radars were upgraded to multi-static capabilities thanks to the development of the MMARIA concept.