| 摘要 |
<p>A system for determining the ground velocity of an aircraft (19). The system includes a CCD linear optical image sensor (11) carried by the aircraft (19) for forming a first and second substantially instantaneous light intensity contours (25, 26) of the optical image of the surface of the earth lying below the aircraft (19). The two contours (25, 26) are delayed in time with respect to each other. A computer (13), included in the system, compares the two contours (25, 26) to determine the relative position shift between the two contours (25, 26) by utilizing cross-correlation techniques. The computer (13) then corrects the contour position shift for the aircraft altitude and divides the corrected position shift by the time delay between the contours (25, 26) to obtain the aircraft ground velocity. A signal indicative of the aircraft ground velocity is output by the system. </p> |
