Digitized Doppler Signal Processor

Abstract

At the present time there is a requirement for developing an airborne approach for processing radar doppler video data into digital PCM format compatible with current IRIG standards. Techniques for digitizing the doppler video presently exist, but have limitations due to the fact that the data is processed and represented in the time domain. These limitations can be mainly attributed to the high bit rates required for quantizing the dynamic nature of the doppler signal. Therefore, an alternate approach was selected by which the video doppler data is converted and represented in the frequency domain. The time to frequency domain conversion is accomplished with a digital Part Fourier Transform (FFT) implemented in conjunction with a quadrature translator. This method will provide a means by which the doppler signal can be represented as a quasi-static spectrum. The advantage in this application is that only the spectral data which contains relevant engineering information will be processed. The resultant system will thereby minimize the transmission bit rate and maximize the dynamic range for the purpose of signal analysis. The paper will describe the implementation and work performed on the digitized doppler signal processor along with the potential application in PCM systems requiring spectral signal analysis.