| 摘要 |
The system utilises the correlation function between two pseudorandom sequences. The correlation is done between the sequence which modulates a laser aimed at the measurement surface 8 and that received after the corresponding optical pathway. The relationship between correlations indicates the delay and, therefore, the distance d measured. It has a generator of pseudorandom sequences 2 which receives a clock signal 1 and which is applied to a laser modulator and emitter 3, as well as to a sequence delay unit 6. Said emitter 3 emits onto the measurement surface 8 and the corresponding reflected signal is captured by an optical receiver 4 whose output, together with that of the delay unit 6, is taken to a correlator 5. This correlator 5 is connected to a digital computation and control unit 7 which in turn is connected to the delay unit 6. <IMAGE>
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