A novel technique is described that employs intelligent processing of multiple ultrasonic range measurements for accurate surface profile extraction and mapping. It aims to overcome the intrinsic angular uncertainty of ultrasonic sensors, as well as eliminating noise and crosstalk related misreadings. Experimental verification is provided where the ultrasonic range data is acquired through wall following. The technique is evaluated based on three complementary error criteria. Compared to the most recently reported arc-transversal median algorithm, the proposed technique provides about 50 smaller mean absolute error, 28-50 higher correct detection of pixels as full and empty, and 10-15 times smaller CPU time, which is less than a tenth of a second. The method is also superior in eliminating artefacts.