Patent ID: 7499829
Filing Date: 2009-03-03
Classification: G01S

Abstract:
1. A method for finding a range, comprising: (a) receiving laser beams reflected from a target, and converting the same into a corresponding photocurrent signal, and converting the signal into a voltage signal; (b) canceling a noise component from the voltage signal and converting the noise-cancelled voltage signal into range-finding data; (c) sequentially storing the range-finding data; (d) adding the stored range-finding data and previously processed and stored accumulated data, and storing results as accumulated data; (e) detecting data exceeding a threshold value from among the accumulated data as target signals; and (f) reading a target range based on the detected target signals, wherein (a) through (d) are repeated N times, and the accumulated data in (e) are obtained by repeating (a) through (d) N times, whrerin (b) further includes differentiating the voltage signal to cancel a voltage component that corresponds to the noise component and is superimposed on the voltage signal; and filtering the differentiated signal with a predetermined frequency bandwidth identical to a frequency band of the target signal, wherein the bandwidth satisfies 0.35/t