Electro-optical imaging array with profiled foward motion compensation

DETAILED DESCRIPTION These and other objects, advantages, and features of the invention can be achieved in a system comprising an array of cells arranged in rows and columns for generating pixel information representing a scene.
Generally, the columns of the array are arranged in column groups and the charge is transferred in each column group at different transfer rates.
In one principal aspect, the invention is a method for processing the pixel information which compensates for scene topography variation and comprises the steps of: generating first and second images of the scene, the second image generated at a later point in time from the generation of the first image; deriving from the first and second images the image velocity of the scene in the plane of the array of cells; and transferring the pixel information through the array at a rate substantially equal to the derived image velocity, whereby resolution of an image created from the pixels is preserved.
The step of deriving the image velocity of the scene from the first and second images, in the preferred embodiment of the invention, involves the step of performing a correlation of the first and second images to determine the distance a fixed point in the scene is displaced in the plane of the array of cells in the duration T between the first and second images.
When multiple column groups are used in the array, a fixed point in each column group is used in the correlation process.
Knowing the displacement and the time duration T between the successive images, a residual image velocity U.
sub.
.
delta.
can be derived.
By continually adjusting the charge transfer rates between successive images and forcing the residual image velocity U.
sub.
.
delta.
to zero, the image transfer rate is synchronized with the true image velocity.
The step of correlating the first and second images may involve the computation of the Fourier spectrum of the first and second images, or may involve a different correlation routine.
The step of transferring pixel information preferably involves the calculation of pixel information transfer rates for each of the column groups from the derived image velocity for each column group, and transferring of pixel information in each of said column groups at the calculated pixel information transfer rate for each column group