| The wind profiler is one kind of remote sensing instrument. It takes the atmospheric turbine as the tracer, continually measures it. The profiler can present high temporal and spatial resolution vertical profiles of the horizontal and vertical wind. The signal processing is a critical step in the wind profiling extraction. Though using high sensitivity radar receiver, the single clear air pulse backscattering is also very weak, the SNR of the backscattering is between –20 to –40dB upon different frequencies. So it's impossible to identify the object during one pulse period. Actually, before the processing, a large quantity of signal coherent accumulation is done, by doing so, it's possible to acquire useful information. To obtain large number of data, the radar must have high PRF, this inflicts the higher requirement in the signal processing. According to the characteristics of the signal, high efficiency chips are needed to satisfy the real time requirement. The platform discussed in this paper is based on two high performance DSP chips and one FPGA chip. The double DSP chips are the cores of the signal processing. Loose interconnection is preferred between them, thus them can not only exchange data speedily and efficiently, but also have little impact on each other. The FPGA chip is a coprocessor, two kinds of connection between it and the DSP chips are introduced, the simplified external port connection and the enhanced link port connection, which act as the fast data transfer channel. The data exchange between the DSP chips and the computer is also supported in the platform. Thus the computer can do the postprocessing. The transfer protocol is fulfilled by the PCI bridge. As to the software, because of the feeble signal, large quantity of data and the real time requirement, high efficiency meteorological processing method is needed. The data processing is constituted of the following steps: the coherent accumulation of the I/Q temporal data, the spectrum analysis, the noncoherent accumulation of the spectrum data, the abstraction of the signal spectrum, the estimation of the radial speed data, the temporal averaging of the radial speed data, the calculation of the wind information. In this platform, the coherent accumulation is fulfilled in one DSP chip, the temporal averaging of the radial speed data and the wind information calculation are performed in the computer, while the other steps are fulfilled in another DSP chip. The processing allocation is reasonable and the method is feasible. |
