Design and Initial Implementation of Array Weather Radar

With the development of phased array technology and networked radars, focusing on the requirement of small-scale weather fine detection, the array weather radar (AWR) is developed, which is a distributed and highly collaborative radar. The traditional Doppler weather radar can obtain radial velocity of cloud or precipitation targets. However, single radial velocity of a spatial point cannot reflect the movement information of precipitation and atmosphere. A multi-radar network can obtain a plurality of radial velocity values using a collaborative detection method, but disadvantages are that the time difference of the same single spatial point obtained by multiple radars is high, leading to composition error of the velocity or invalid observation.The AWR comprises at least three phased array transmit-receive subarrays (subarrays for short), and the detection region of the AWR can be enlarged by increasing the number of subarrays. The AWR employs a multi-beam phase array scanning technology, which has 4 transmission beams and 64 receiving beams covering an elevation angle between 0° and 90°. And meanwhile, a 360° azimuth is covered by mechanical scanning. One volume scanning time of the AWR is 12 s which are several tenths of the traditional Doppler weather radar. Each three adjacent subarrays work as a group, which performs collaborative scanning to ensure data time differences at the same spatial point from three adjacent subarrays are less than 2 s, and then correct flow fields can be synthesized by using radial velocity of the subarrays. This is a big progress in acquiring thermodynamic information and dynamic information of precipitation targets.One AWR consisting of three subarrays has been deployed at Changsha Airport and has acquired three-dimensional velocity and intensity (reflectivity factor) data, and more fine information of small-scale weather systems may be obtained by using data. There are still a lot of problems to be solved and a lot of works to be done in the field of the AWR technology and application.