Semi-active laser guidance technology has been extensively used in missiles

artillery shells and aerial bombs due to its high precision

but target laser indicator which matches to the guidance technology

is the most important issue for operational flexibility. According to the request of target passive acoustic localization in whole space for unattended laser target indicator

a stereo acoustic array with 5 acoustic sensors was designed and made

the localization parameter expressions were deduced in addition. The experiment for a hovering helicopter has been made

and the analyzed results show that

the acoustic array can estimate azimuth angle

pitch angle

and distance of the target

especially the error of angle estimation was less than 2°.