Method and apparatus for making a temperature-referenced color strip map of thermal variations

Claim 2

In the method of making a temperature referenced ground map of thermal variations in a ground scene wherein an aircraft is flown along a predetermined flight path over said ground scene while thermal ground data is simultaneously acquired from said ground scene along scan lines generally transverse to said flight path, electrical data signals are generated representing said thermal ground data, electrical timing signals are generated having a predetermined timing relationship to acquisition of data along said ground scan lines, said data signals and said timing signals are stored on recording media and subsequently extracted therefrom to generate a color display adapted to be exposed on color film to thereby produce a ground map of thermal variations in said ground scene, that improvement wherein thermal reference data is acquired in real-time coincidence with acquisition of said thermal ground data, electrical reference signals representing said thermal reference data and recorded on said recording media and subsequently extracted and wherein the effect of said extracted data signal on said color display is modified in accordance with said extracted thermal reference signals.

Claim 5

The method set forth in claim 2 further comprising providing a second thermal reference, recording and then subsequently extracting a third electrical signal representing said second thermal reference, and setting a second amplitude limit of said range in accordance with said third signal, and wherein said first, second and third electrical signals are combined into a composite thermal signal prior to recording, said second electrical signal is extracted from said composite signal after recording by sampling said composite signal, said third electrical signal is extracted from said composite signal after recording by sampling said composite signal, said first and second amplitude limits of said range are set according to said second and third electrical signals sampled from said composite video signal, and said digital output signals are generated by comparing the instantaneous amplitude of said first signal to said second and third electrical signals.

Claim 6

The method set forth in claim 3 implemented by a rotatable scanning mirror having an active face thereon adapted to focus thermal energy on a thermal-to-electrical detector, and wherein said first, said second and third thermal signals are generated by exposing said face during a revolution of said mirror to a first source of thermal energy at a first temperature, a second source of thermal energy at a second temperature and said thermal ground data to thereby develop at said detector a composite electrical signal having portions thereof representing said first temperature, said second temperature and said thermal ground data.

Claim 7

The method set forth in claim 4 wherein timing signals are generated in synchronism with rotation of said mirror, and said timing signals comprising a first timing pulse generated substantially in time coincidence with viewing of said first source by said mirror face and a second timing pulse is generated substantially in time coincidence with viewing of said second source by said mirror face.

Claim 8

The method set forth in claim 5 wherein said mirror first views said first source, then views said thermal ground data and then views said second reference source.

Claim 9

The method set forth in claim 2 implemented by color display means having a plurality of electron beam generating means therein adapted to be selectively energized to produce color variations in said display, and wherein said output signals are generated by comparing said first signal to said one limit and a plurality of reference levels representing said subranges signals to obtain a plurality of digital output signals representing predetermined instantaneous levels in said first signals and then selectively energizing said beam generating means according to said output signals.

Claim 10

The method set forth in claim 7 wherein said beam generating means in said display means are selectively gated on at predetermined fixed intensity levels in accordance with said digital output signals to obtain color variations in said display.

Claim 11

The method set forth in claim 2 implemented with line-scanned display means, and wherein said display is generated a line at a time by initiating each line at said display in accordance with timing signals and varying the color of said display along each line in accordance with said first signal, and wherein color film is exposed by said display by moving a continuous strip of color film past said display in a direction generally perpendicular to the direction of line scanning on said display.

Claim 12

The method set forth in claim 9 wherein said display means has a plurality of beam generating means therein adapted to be selectively energized to produce color variations in said display, and wherein said digital output signals are generated by comparing said first signal to said one limit and to a plurality of reference levels representing said subranges to obtain a plurality of digital output signals representing predetermined instantaneous levels in said first signals and selectively energizing said beam generating means according to said output signals.

Claim 13

The method set forth in claim 9 wherein said beam generating means in said display means are selectively gated on at predetermined fixed intensity levels in accordance with said digital output signals to obtain color variations in said display.

Claim 14

The method set forth in claim 10 wherein said first thermal reference is provided at a first predetermined time during a scanning cycle, said first and said second signals are combined into a composite thermal signal prior to recording said one amplitude limit is set by sampling said composite signal at a time in synchronism with said first predetermined time and wherein said reference levels are established at predetermined amplitude increments from said first limit.

Claim 17

Apparatus for creating a continuous color film strip from a thermal scene comprising means for generating a composite video signal representing thermal data acquired from said scene along a plurality of scan lines and temperature reference data acquired during acquisition of said thermal data, means providing timing signals according to scanning along said lines, line-scanned color display means responsive to said timing signals to synchronize line scanning on said display means with line scanning of said scene, said color display means including a plurality of electron beam generating means for causing color variations on said display, first signal processing means responsive to said composite video signal for developing a first reference signal representing a first temperature reference in said temperature reference data, second signal processing means responsive to said composite video signal and said first reference signal to generate digital signals representing instantaneous amplitudes of said thermal data within a predetermined number of amplitude sub-ranges contained in an amplitude range calibrated by said first reference signal, gating circuit means responsive to selected digital signals to generate a line-scanned color display having a number of predetermined colors therein substantially equal to said predetermined number, and color camera means for exposing color film to said display.

Claim 18

Apparatus for creating a continuous color film strip from a thermal scene comprising means for generating a composite video signal representing thermal data acquired from said scene along a plurality of scan lines and temperature reference data acquired during acquisition of said thermal data, means providing timing signals according to scanning along said lines, line-scanned color display means responsive to said timing signals to synchronize line scanning on said display means with line scanning of said scene, said color display means including a plurality of electron beam generating means for causing color variations on said display, first signal processing means responsive to said composite video signal for developing a first reference signal representing a first temperature reference in said temperature reference data, second signal processing means responsive to said composite video signal and said first reference signal to generate digital signals representing instantaneous amplitudes of said thermal data within a predetermined number of amplitude sub-ranges contained in an amplitude range calibrated by said first reference signal, gating circuit means responsive to selected digital signals to generate a line-scanned color display having a number of predetermined colors therein substantially equal to said predetermined number, and color camera means for exposing color film to said display.

Claim 19

The apparatus set forth in claim 14 wherein said temperature reference data also includes a second temperature reference, said first signal processing means is responsive to said composite video signal to generate a second reference signal representing said second temperature reference, and wherein said second signal processing means includes means for calibrating said amplitude range according to both said first and second reference signals.

Claim 20

The apparatus set forth in claim 15 wherein said signal processing means comprises means for sampling said composite video signal to develop said first and second reference signals representing said first and second temperature references.

Claim 21

The apparatus set forth in claim 16 wherein said signal processing means comprises voltage divider means responsive to said first and second reference signals to provide a plurality of incremental reference signals, a plurality of level detection circuit means each of which has a reference input coupled to a respective one of said incremental reference signals and a signal input for said thermal data, each of said detection circuit means being adapted to provide a respective digital signal when said reference data exceeds a respective incremental reference signal, and circuit means coupling the output of said detection circuit means to said gating circuit means to selectively actuate said gating circuit means individually and in predetermined combinations according to said digital output signals.