Predetection processing of optical information

An optical processor for processing optical information from a scene being viewed by a sensor prior to detection comprising:

• a thermoptic modulator positioned in the image plane of the sensor, said modulator having an optical structure disposed at the faceplate thereof, said optical structure being substantially nonreflecting of optical energy, but capable of having reflecting spots written at selected coordinates thereon for reflecting optical energy incident at said spots, said modulator including writing means capable of selectively writing reflecting spots at selected coordinates on said optical structure;
• control means connected to said writing means for causing a series of reflecting spots to be written at selected coordinates on said modulator, said control means capable of selectively controlling the size and shape of each of said spots and capable of switching said writing means on and off;
• and
• detector means positioned to view said modulator for detecting optical energy reflected from said modulator, said detector means providing a series of output signals representing the radiance of the scene elements reflected from each of said reflective spots written on said modulator.

An optical data processor for preprocessing infrared information from a scene being viewed by an infrared sensor comprising:

• a thermoptic modulator positioned in the image plane of the sensor, said modulator having an optical structure disposed at the faceplate thereof, said optical structure being substantially nonreflective of infrared energy, but capable of having reflecting spots written at selected coordinates thereon for reflecting infrared energy incident thereon, said modulator including writing means capable of writing reflecting spots at selected coordinates on said optical structure;
• control means connected to said writing means for causing a series of reflecting spots to be written at selected coordinates on said modulator, said control means capable of controlling the size and shape of said reflecting spots and switching said writing means on and off;
• detector means positioned to view said modulator for detecting infrared energy reflected therefrom, said detector means providing a series of output signals representing the radiance of the infrared scene element reflected from each of said reflecting spots written on said modulator;
• signal processing means connected to said detector means for processing first and second output signals corresponding to first and second reflecting spots written at the same coordinates on said modulator, said first spot being smaller than said second spot, said processor subtracting said second spot from said first spot to obtain a band pass filtered signal;
• and
• video display means connected to said signal processing means and responsive to said filtered signal for visually displaying said filtered signal at coordinates on said display corresponding to coordinates in the scene.

A method for processing optical information in an optical sensor comprising the steps of:

• (a) successively writing a series of reflecting spots of predetermined size at selected coordinates on a thermoptic modulator;
• (b) reflecting successive scene elements in the total field of view of the sensor from the reflecting spots written in step (a) to a detector positioned to view said modulator;
• (c) detecting the radiance values of successive scene elements reflected from said modulator in step (b);
• and
• (d) generating a series of output signals representing the radiance of the scene elements detected in step (c).

A method for processing optical information in an optical sensor comprising the steps of:

• (a) successively writing a series of reflecting spots of predetermined size at selected coordinates on a thermoptic modulator, said coordinates being selected such that a portion of said spots are written at coordinates sufficiently close together to define at least one window for viewing the scene;
• (b) reflecting successive scene elements in the total field of view of the sensor from said reflecting spots and said windows written in step (a) to a detector positioned to view said modulator;
• (c) detecting the radiance values of successive scene elements reflected from the modulator in step (b);
• and
• (d) generating a series of output signals representing the radiance of the scene elements detected in step (c).

A method for processing optical information in an infrared sensor to reduce background clutter comprising the steps of:

• (a) writing a first reflecting spot of predetermined size at selected coordinates on a thermoptic modulator;
• (b) generating a signal representing the radiance of the infrared energy reflected from said first reflecting spot written on the modulator to a detector;
• (c) writing a second reflecting spot on said modulator having the same coordinates as said first reflecting spot, said second spot being larger than said first spot;
• (d) generating a second signal representing the radiance of the infrared energy reflected from said second reflecting spot to said detector;
• and
• (e) subtracting said second signal obtained in step (d) from said first signal obtained in step (b) to obtain a spatially filtered signal.