| 摘要 |
<p>PURPOSE: To correct the characteristics of an antenna to prevent the deterioration of resolution and to suppress the change of an investigating video by deciding the coefficient of a filter based on the signal received by a reference antenna provided in addition to the antenna to be used. CONSTITUTION: First, changeover switches 20, 21 are connected to the sides of reference antennas 12a, 12b, and a changeover switch 22 is connected to the side of a received reference waveform memory 15. A testpiece 23 is inserted, a base band pulse is transmitted from a transmitter 10, received by a receiver 13, and the waveform is stored in the memory 15. Then, the switches 20, 21 are switched, and the received waveforms via comparison antennas 11a, 11b are stored in a received comparison waveform memory 14. Thus, the memory 14 stores the waveform Fm, and the memory 15 stores the waveform Fo. A comparison calculator 16 compares the waveform Fm with the waveform Fo to obtain filter coefficient data. The coefficient is set in a reverse filter 18 to correct the received waveform Fm, and video data is output.</p> |
