Theoretical Analysis on Range Accuracy of Laser Fuze

Ranging accuracy is one of the important parameters which are used to evaluate performance of laser fuze. It´s actually measure the flight time of laser when the laser fuze measuring the range of target. The pulse system carries on the time measuring directly, but the continuous wave system obtains the flight time indirectly through the difference frequency from the echo wave mixed local oscillation. Threshold method is often adopted to detect echo signal of pulse-gated laser fuze, but if the waveform of detected laser signal distorts or fluctuates with extraneous disturbances, using threshold method often leads to large measurement error and low accuracy. Through analysis the interior and external cause of ranging error on the linear frequency modulation continuous wave(LFMCW) laser fuze, the ranging error which caused by interior noise is less than 5cm when the false alarm probability is 10-4 and the probability of detection is 99.99%. The ranging error which caused by aerosol is less than 11cm when the visibility is under 40m. The total ranging error of laser fuze is less than 16cm. The simulation result shown that the ranging accuracy of LFMCW laser fuze satisfies the ranging request of pinpoint attack ammunition completely.