The Research On The Key Technology Of Phase Array Weather Radar

In order to meet the need of detecting fast variable severe weather in atmospheric observation operation, the principle of choosing the type of phase array weather radar is proposed in this paper according to the fast scanning feature of phased-array weather radar, that is except for airborne phased-array radar and satellite-borne phased-array radar, one-dimensional or two-dimensional planar array are usually used in ground-based conventional phased-array radar.According to the different constructive features in antenna front of one-dimensional and two-dimensional phased-array weather radar, subsystems are used to make these two types of phased-array weather radar meet the need of atmospheric detecting. Several important indexes are discussed and computed in this paper, and a new radar meteorological equation which is suitable for phased-array weather radar is deduced.To improve the sensitivity of weather radar, pulse compression technology which can improve the delicacy of radar system and range resolution is applied in phased-array weather radar. Pulse compression technology is a kind of signal processing technology and usually used in wind profile radar and military tracking radar. As to its application in ground-based radar, the study is still in the stage of research. In this paper, the impact of pulse compression on radar antenna sidelobe has been illustrated, as well as using Matlab program to compute the impact of different methods of pulse compression such as linear frequency modulation, nonlinear frequency modulation and phase code on the distance sidelobe. This paper advocates applying the nonlinear frequency modulation pulse compression in atmospheric observation operation, for this technology can beneficially reduce the impact of phased-array technology on the quality of echo data.In order to track and identify the varying process of weather phenomenon more precisely and make the best use of phased-array technology, raising the scanning speed of antenna substantially was utilized, but at the sometime the problem that the samples in every distinguishable volume decreasing with the individual samples’ decreasing exists. The oversampling technology which analyzes individual compositions was adopted in this paper, the oversampling at same distance intervals makes the weather echo signal de-correlation, which can improve the accuracy of the estimation of Doppler frequency shift. Based on independent component analysis (ICA) algorithm, this paper analyzes and processes the random signals and real radar signals successively, which is designed to increasing the number of individual samples and get the sounding data of the same precision in less scanning time. The fast scanning speed of phase array weather radar appears more worthy by applying this technology.By using those technologies mentioned above, it can give full play to the advantage of phased-array radar on detecting severe weather, and remedy the impact on the quality of data during the working of phased-array weather radar, which can make phase array weather radar be utilized in modern atmospheric detecting operation as an advanced observing method.