Wednesday, June 8, 2011

P-70 Lena-M Radar

The P-70, known as "Lena-M", was a static 2D very high frequency radar developed and used by the former Soviet Union. The P-70 radar was designed as a static structure mounted on a two story building which housed the radar and power supply equipment as well as facilities for the radar operators. P-70 radars were dual-channel with the antenna working in both horizontal and vertical polarization. The radar used a single large antenna accomplishing both transmission and reception with a surface area of 850 m2 and with dimensions of 48 by 25 meters. The antenna was of the open frame truncated parabolic variety and was scanned mechanically in azimuth using hydraulics.

The use of these techniques gave the P-70 excellent resolution, by a factor of 10 compared with the P-14, at long range, as well providing protection against active and passive interference. The radar operated on two frequencies, 140 MHz to observe low altitude targets (aircraft and missiles) and 70 MHz to observe high altitude targets (satellites). The P-70 also used a fully-coherent transmitter and an MTI system capable of compensating for wind and other forms of passive interference such as chaff, overall the P-70 managed to achieve a low false alarm rate.