| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To support observation processing that uses radio waves by enhancing the degrees of freedom of PRI, and enlarging the observation width. <P>SOLUTION: A transmission part 120 transmits a transmission wave, relative to each PRI without having to take the reception timing of reflected waves from the directly vertical direction into consideration, and a receiving part 130 receives the reflected waves reaching an antenna 110 at a reception timing. An attenuation timing calculation part 142 calculates the reception timing of the reflected waves from the directly vertical direction, based on the distance between the directly vertical direction and an observation device 100, and outputs a pulse for attenuation. By having an attenuator 141 attenuate the received signal during output of the pulse for attenuation by a large amount, the reflected waves are prevented from a main lobe, superimposed on the reflected wave from the directly vertical direction having a large power from being lost due to the saturation of the signal. Thereafter, an A/D converter 151 performs A/D conversion of the received signal. Then, an effective bit number switcher 152 enlarges the effective bit number of the A/D conversion to increase the resolution during output of the pulse for attenuation, reduces the effective bit number of the A/D conversion, and suppresses the data amount during non-output of the pulse for attenuation. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
