MSTRadar


The MST radar located at Gadanki is an excellent system used for atmospheric probing in the regions of Mesosphere, Stratosphere and Troposphere (MST) covering up to a height of 100 Km. It is also used for coherent backscatter study of the ionospheric irregularities above 90 km. MST radar is a state-of-the-art instrument capable of providing estimates of atmospheric parameters with very high resolution on a continuous basis, which is essential for the study of different dynamical process in the atmosphere. Radar operates at 53 MHz with a peak power of 2.5 MW. The phased antenna array consists of two orthogonal sets, one for each polarization of 1024 three element Yagi-Uda antennas arranged in a 32 x 32 matrix over an area of 130 m x 130 m. The two sets are co-located with pairs of crossed Yagis mounted on the same set of poles. The array is aligned along the geomagnetic axes to enable the radar beam to be transverse to the Earth’s magnetic field for ionospheric backscatter application. The array of either of the polarizations is illuminated using 32 transmitters of varying power, each feeding a linear sub-array of 32 antennas. The power distribution across the array follows an approximation to modified Taylor weighting in both principal directions. The radar beam can, in principle, be positioned electronically at any look angle within ± 200 off-zenith in the East-West and North-South planes. It is possible to transmit both coded and un-coded pulses with pulse repetition frequency in the range of 62.5 Hz to 8 KHz, with a maximum duty of 2.5 %. Coded and un-coded pulse can be varied from 1 to 32 µs with a baud length of 1 µs providing a range resolution of 150 m. The radar operates under instruction from a PC based radar controller that executes an experiment according to the experimental specification set by the scientists. Both time series and power spectrum data canbe recorded on-line. The recorded data can be processed offline to derive various atmospheric parameters.