1. A feature imaging and adaptive focusing synthetic aperture process comprising the steps of: predicting expected echo delays between a sensor and a target for each pixel coordinate of an image representative of the target and its environment formed from echo data; calculating possible perturbations to the expected echo delays; beamforming image data of an echo sequence and constructing a test image for each possible or hypothesized echo delay perturbation at each pixel coordinate; calculating the mean square bandwidth of each test image; selecting the best test image having the largest value of mean square bandwidth resulting in the best local focus for each image pixel; subtracting the predicted expected echo delays from the perturbed delays of the best test image for each image pixel; estimating relative motion of the sensor with respect to each point of the imaged target and its environment; and constructing a motion compensated image from the best test image of the echo sequence.