The Processing Methods Of Pulse Doppler (PD) Weather Radar Radial Direction Velocity Datum And Identification Of The Low Level Jet

This thesis discusses the signal processing methods of Pulse Doppler (PD) weather radar, mainly studying filter algorithms, Range-Velocity (RV) ambiguity resolution methods and using Doppler radar Data to analyze low level jet.Firstly, we brings the new mixed filter algorithms (WK algorithms) of the 2D Wavelet transform and Kalman Filter, which has the character of the well time-frequency localization and real-time. The WK algorithms are used to process the radar information and makes the filter estimated data to approach the true track.Second, this paper study the normal velocity-ambiguity resolution algorithms. In the base of the studing the alternating pulse method, ambiguity resolution algorithms is analysed in detail by using the limited condition of velocity estimated formula of the time domain pulse pair processor, and we adjust this formula. We study the normal range-ambiguity resolution algorithms. In the base of the studing the phase-coded method, we give a new phase-coded sequence, which can increase the spectrum discrete degree of the unexpectation echo, and we give the corresponding frequency domain processing method, which can pick up the want from the overlap echo in better and is easier to process in real time.Finally, this paper study a lot of character of the low level jet and the radar data. We insert the radial direction velocity datum in a column grid by the 3-D insertion method. Then, basing the vertical changing of the horizontal wind velocity on the basis of the definition in low level jet, and calculate the gradient velocity of the distinct levels horizontal wind velocity in the same azimuth. At last, by the relationship of horizontal wind velocity and radial velocity, we canobtian the same azimuth, and find the threshold and term. So we can identify the low level jet.