Accurate measurement of departure distance from aircraft to runway centerline based on images of forwardlooking runway

According to the optoelectronic requirement of minimum control speed flight test for civil planes, an accurate measurement technology of department distance from aircraft to runway centerline based on images of forwardlooking runway was proposed. A highspeed digital camera was mounted on the ventral centerline to obtain the forwardlooking images of runway and aircraft landing gear of the running plane. With image interpretation, subpixels coordinates of intersection on aircraft main wheel connection and runway flag line were identified. With the highaccuracy calibration of camera measurement parameters and singlestation location theory of photogrammetry, the object space coordinates of the intersection could be accurate calculated, and then the distance from aircraft to runway centerline could be obtained. The measurement result of flight tests shows that this measurement scheme is feasible, the measurement result is reliable, and the measurement accuracy of 3 cm can be realized, which can meet the requirements of flight tests.