| 摘要 |
Receiver for a sounder for the detection and measurement of phenomena linked with the earth's environment, wherein it comprises a reception channel, whereof one input receives the echo signals of the electromagnetic signals emitted towards the phenomenon, an electromagnetic signal frequency shift and amplitude-calibration test channel, whereby the reception channel comprises a first stage having in series means for filtering, attenuating and amplifying the echo signals received, a second stage comprising in series means for the frequency conversion attenuation, filtering and amplification of the signals received from the first stage, and a third stage comprising in series means for frequency conversion, filtering and amplification of the signals received from the second stage, the attenuation means of the first and second stages being independently controllable for each frequency of the signals which they receive, in such a way that the signals from the corresponding amplification means have an amplitude higher than the amplitude of the distortions produced by the reception channel and the amplitude of the interference signals received by the reception channel. |
