ST Radar system of ARIES for Wind Profiling over Himalayas

Increasing interest in the Himalayan Environment has resulted, in view of the Global warning scenario including Transboundary flow of aerosols and pollutants and the need for characterizing winds, waves turbulence and Aerosol optical depth, etc. of the neutral atmosphere over the Himalayan region. Aryabhatta Research Institute for Observational Sciences (ARIES) located at Nainital(29.24⁰N,79.28⁰E) at an altitude of 6250 m is making Aerosol optical depth measurements using LIDARS and other atmospheric measurements routinely. In order to augment the facilities for measurement of atmospheric dynamics, and to study exchanges between different layers of atmosphere, Stratosphere Troposphere (ST) radar with height coverage of 20 Kms is being established. Based on this initiative the Department of Science and Technology of the Government of India is planning for a network of such ST radars, over the subcontinent. This paper describes the design aspects of the active aperture phased array radar designed at 206.5 MHz for measuring three dimensional wind vector over the troposphere and lower stratosphere regions of the tropical atmosphere. As a proof of design one sub array of 49 elements was integrated with the exciter and receiver signal processor and trial runs were made at ECIL Hyderabad. The results obtained shows wind profiles upto 6 to 7 kms, which was as per expectations and thus validated the design approach. Horizontal winds obtained were compared on a day (April 25, 2012), when a GPS sonde of opportunity was launched from Hyderabad.