| 摘要 |
<p>PURPOSE: To remove an interference wave even if the interference wave is continuously contained in reflecting wave by installing a frequency analyzer which analyzes digital signal of the reflecting wave in a spectrum of frequency and signal intensity. CONSTITUTION: A reflecting wave is inputted in an A/D convertor 1 to be converted into a digital signal in which a pulse repeating period is divided for every specified time intervals, that is, every specified distances. The digital signal is inputted in the order of a divided number in the address of an input buffer part 2. Data of the reflecting wave necessary for conducting high speed Fourier transform processing in the frequency analyzer 3 is accumulated in the input buffer part 2. The frequency analyzer 3 analyzes a digital signal in the same dividing position of a plurality of reflecting waves into a frequency and signal intensity, and an average value calculating part 4 calculates the average value of the signal intensity of each frequency. A removable signal deciding part 5, when difference between the average value of the signal intensity of a received frequency corresponding to the frequency of a transmitted pulse and the average value of the signal intensity of other frequency is less than a specified value, decides the reflecting wave as the interference wave and removes.</p> |
