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Learn about SuperDARN | |
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The SuperDARN network is currently comprised of nine radars in the northern hemisphere and six in the south. The construction of all the radars is virtually identical, with some minor differences in Antenna design and to accommodate the physical conditions at the site. Each of the radars has two arrays of antenna towers, the primary array consists of sixteen towers, and the secondary, interferometer array, consists of four towers. A phasing matrix attached to the antenna array is used for beam forming and to electronically steer the radar into one of sixteen different beam directions. The radar transmits a short sequence of pulses in the HF band and samples the returning echoes. The sequence of pulses, referred to as a multi-pulse sequence, is carefully designed to allow the Doppler characteristics of different targets to be determined at multiple ranges by using the Auto-Correlation Function of the received samples. Many sequences are transmitted and the calculated ACFs integrated over a period of several seconds to minimize the effect of noise. The final average ACF is then used to calculate the back-scattered power, spectral width and Doppler velocity of the plasma density irregularities in the Ionosphere. In the standard operating mode, a 7 pulse, multi-pulse sequence is transmitted and a sampled to resolve 75 ranges with a 45 km separation. Each of the radars is controlled by a system of three networked PCs running the QNX and Linux Operating Systems. The operation of the Radar is controlled by the Radar Operating System (ROS), which is responsible for controlling the Radar hardware, data processing and analysis, and data storage. A "Radar Control Program" defines the overall mode of the Radar, including the operating frequency, integration period, range separation and beam pattern used. The entire network is coordinated by an agreed schedule that defines which control program should be run and at what times during the course of the month.
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