Patent ID: 6757054
Filing Date: 2004-06-29
Classification: G01S

Abstract:
A time measurement apparatus comprising:a shift clock signal generating means for generating a plurality of shift clock signals in response to a reference clock signal, the shift clock signals having a period equal to a period of the reference clock signal, the shift clock signals having phases different from each other; signal inputting means for converting an input signal into binary signals in response to the shift clock signals generated by the shift clock signal generating means respectively, the input signal containing a pulse train of a pseudo random noise code; correlation calculating means for calculating correlations between the pseudo random noise code and the binary signals generated by the signal inputting means; detecting means for detecting a moment at which a peak of the correlations calculated by the correlation calculating means occurs; and measuring a time interval from a prescribed moment to a moment of occurrence of the pulse train in the input signal on the basis of the moment detected by the detecting means.