Abstract: An apparatus and method for determining aircraft position and velocity is disclosed. The system includes two CCD sensors which take overlapping front and back radiant energy images of front and back overlapping areas of the earth's surface. A signal processing unit digitizers and deblurs the data that comprise each image. The overlapping first and second front images are then processed to determine the longitudinal and lateral relative image position shifts that produce the maximum degree of correlation between them. The signal processing unit then compares the first and second back overlapping images to find the longitudinal and lateral relative image position shifts necessary to maximize the degree of correlation between those two images. Various correlation techniques, including classical correlation, differencing correlation, zero-mean correction, normalization, windowing, and parallel processing are disclosed for determining the relative image position shift signals between the two overlapping images.

Abstract: A selective deceleration brake control system which enables the operator of an aircraft or other vehicle to preselect a rate of deceleration for the vehicle. The system produces a velocity reference signal which decreases in value at a rate indicative of the rate of vehicle deceleration selected by the operator. A signal indicative of actual wheel velocity is continuously produced and compared with the velocity reference signal to generate an error signal. The error signal is processed and used to produce a brake control signal. The system continuously controls braking effort to cause the vehicle to decelerate at the rate selected by the operator. The selective deceleration circuit cooperates with an anti-skid brake control circuit such that at any instant the circuit providing the higher brake release command will control.