| 摘要 |
The telemetry system using continuous waves comprises a source (10-18) transmitting modulated microwaves to which a coding (PN) has been applied. An aerial (20) serves to receive the reflected signals, and a circuit (38) determines the delay and relative energy in the return signal. A further circuit (32-37) processes the return signal in order to distinguish between the reflections which are due to the target and the reflections which are due to particles. A further circuit (15,16,16') applies additional modulation (FB) to the transmitted signal, and the power of the returned signal within a side band on either side of this additional modulation is determined. The first modulation is a pseudo-random modulation (PN) whilst the second modulation is a frequency modulation at a given frequency.
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