Cross-correlator

Claim 2

A cross-correlator for processing signal data stored on film comprising, in combination, means for scanning said film with an electron beam; a reference signal; means for modulating said electron beam with said reference signal; means for focusing said modulated beam onto said film; signal forming means operatively disposed to develop information signals in response to energy from said beam penetrating said film; filter means coupled to said signal forming means for passing a predetermined portion of said information signals; and means coupled to said filter means for determining the integral of said portion.

Claim 3

A cross-correlator for processing radar video data stored on film comprising, in combination, means for providing an electron beam, said means operatively disposed to project said beam upon said film; means for deflecting said beam; a reference signal, means for modulating said beam with said reference signal; means for focusing said modulated beam on said film; photomultiplier means operatively disposed to develop a voltage signal in response to energy passing through said film from said beam; filter means coupled to said photomultiplier means for passing a predetermined band of frequencies of said voltage signal; and means coupled to said filter means for determining the integral of said voltage signal falling within said frequency band.

Claim 4

A cross-correlator for processing radar video data stored on film comprising, in combination, means for providing an electron beam, said means operatively disposed to project said beam upon said film; means for deflecting said beam; a reference signal, means for modulating said beam with said reference signal; means for focusing said modulated beam on said film; photomultiplier means operatively disposed to develop a voltage signal in response to energy passing through said film from said beam; filter means coupled to said photomultiplier means for passing a predetermined band of frequencies of said voltage signal; and means coupled to said filter means for determining the integral of said voltage signal falling within said frequency band.

Claim 5

A cross-correlator for processing radar video data stored on film as a function of range in the form of line traces extending across a film strip comprising, in combination, means for scanning a plurality of said line traces in a direction along said film strip with an electron beam; means for modulating said electron beam with a reference signal; optic means for focusing said modulated electron beam as same scans said film strip; signal forming means operatively disposed adjacent said film strip and adapted to receive that energy from said beam which penetrates said film strip to develop information signals in response thereto; filter means electromagnetically coupled to said signal forming means for rejecting all frequencies of said information signal other than those falling within a predetermined passband; and means including detecting and integrating means coupLed to said filter means for determining the output of said filter means, said integral being indicative of the alignment of said stored radar video data with that programmed and represented by said reference signal.

Claim 6

A cross-correlator for processing radar video data stored on film as a function of range in the form of line traces extending across a film strip comprising, in combination, means for scanning a plurality of said line traces in a direction along said film strip with an electron beam; means for modulating said electron beam with a reference signal; optic means for focusing said modulated electron beam as same scans said film strip; signal forming means operatively disposed adjacent said film strip and adapted to receive that energy from said beam which penetrates said film strip to develop information signals in response thereto; filter means electromagnetically coupled to said signal forming means for rejecting all frequencies of said information signal other than those falling within a predetermined passband; and means including detecting and integrating means coupLed to said filter means for determining the output of said filter means, said integral being indicative of the alignment of said stored radar video data with that programmed and represented by said reference signal.

Claim 7

A cross-correlator for processing stored bipolar video data to determine the correlation between same and certain reference data, said stored data being in the form of film density variations extending in the range dimensions across a film strip to form a line trace, successive ones of said line traces being spaced apart in an azimuth direction along said film strip, said cross-correlator comprising, in combination, film transport means for carrying said film strip and including drive means for transferring said film strip to one of two spaced-apart film containers at a predetermined rate; reading means operatively disposed adjacent to said film transport means for sequentially scanning a plurality of said line traces with an electron beam over said range dimension; modulating means coupled to said reading means for intensity modulating said electron beam with a reference signal; optical means disposed intermediate one side of said film strip and said reading means for focusing said intensity modulated electron beam onto said film strip during the scanning sequence; signal forming means operatively disposed adjacent the other side of said film strip for developing an information signal in response to beam energy penetrating said film strip; filter means including an output coupled to said signal forming means for rejecting all frequencies of said information signal other than those falling within a predetermined pass-band; and means coupled to said output for detecting and summing the output signal of said filter means during each scanning sequence to determine said correlation.

Claim 8

A cross-correlator for processing stored bipolar video data to determine the correlation between same and certain reference data, said stored data being in the form of film density variations extending in the range dimensions across a film strip to form a line trace, successive ones of said line traces being spaced apart in an azimuth direction along said film strip, said cross-correlator comprising, in combination, film transport means for carrying said film strip and including drive means for transferring said film strip to one of two spaced-apart film containers at a predetermined rate; reading means operatively disposed adjacent to said film transport means for sequentially scanning a plurality of said line traces with an electron beam over said range dimension; modulating means coupled to said reading means for intensity modulating said electron beam with a reference signal; optical means disposed intermediate one side of said film strip and said reading means for focusing said intensity modulated electron beam onto said film strip during the scanning sequence; signal forming means operatively disposed adjacent the other side of said film strip for developing an information signal in response to beam energy penetrating said film strip; filter means including an output coupled to said signal forming means for rejecting all frequencies of said information signal other than those falling within a predetermined pass-band; and means coupled to said output for detecting and summing the output signal of said filter means during each scanning sequence to determine said correlation.

Claim 9

A cross-correlation for processing radar video data stored as a function of range across a film strip in the form of line traces comprising, in combination, film transport means for supporting said film strip and including means for transferring same from one to the other of two spaced-apart cylinders at a predetermined rate; reading means juxtapositioned adjacent to said film transport means and including means for scanning a plurality of line traces in a direction along said film strip with an electron beam during a time interval; modulating means coupled to said reading means for intensity modulating said electron beam with a reference signal and including means for varying the frequency of said reference signal as a function of range; optical means disposed intermediate one side of said film strip and said reading means for focusing said intensity modulated electron beam onto said film strip; signal forming means including a photomultiplier tube operatively disposed adjacent the other side of said film strip for developing an electrical signal in response to beam electrons penetrating said film strip; filter means including an output electromagnetically coupled to said signal forming means for rejecting all frequencies of said electrical signal other than those falling within a predetermined pass-band; and means coupled to said output for detecting and summing the output signal of said filter means during said time interval to determine the cross-correlation integral at the end thereof, the instantaneous amplitude of said integral being indicative of the degree of correlation between the stored data and that represented by said reference signal.

Claim 10

A cross-correlation for processing radar video data stored as a function of range across a film strip in the form of line traces comprising, in combination, film transport means for supporting said film strip and including means for transferring same from one to the other of two spaced-apart cylinders at a predetermined rate; reading means juxtapositioned adjacent to said film transport means and including means for scanning a plurality of line traces in a direction along said film strip with an electron beam during a time interval; modulating means coupled to said reading means for intensity modulating said electron beam with a reference signal and including means for varying the frequency of said reference signal as a function of range; optical means disposed intermediate one side of said film strip and said reading means for focusing said intensity modulated electron beam onto said film strip; signal forming means including a photomultiplier tube operatively disposed adjacent the other side of said film strip for developing an electrical signal in response to beam electrons penetrating said film strip; filter means including an output electromagnetically coupled to said signal forming means for rejecting all frequencies of said electrical signal other than those falling within a predetermined pass-band; and means coupled to said output for detecting and summing the output signal of said filter means during said time interval to determine the cross-correlation integral at the end thereof, the instantaneous amplitude of said integral being indicative of the degree of correlation between the stored data and that represented by said reference signal.

Claim 11

In a synthetic array data processing system for developing a high resolution display of objects located within an area to be mapped where said system includes coherent radar means operable from a moving craft for providing Doppler shift signals representative of the position of said objects and means for recording said Doppler shift signals on film comprising record scanning means including means for modulating the electron beam thereof with said Doppler shift signal to record same on said film, a cross-cOrrelator device for said processing system comprising, in combination, read scanning means for scanning a plurality of said stored Doppler shift signals for each range successively to develop Doppler history signals for each of said ranges, said read scanning means including means for modulating the electron beam thereof with a reference signal; signal forming means optically coupled to said read scanning means for receiving substantially all of the energy passing through said film from said modulated electron beam to develop a response signal, said film being operatively disposed intermediate said read scanning means and said signal forming means; filter means electromagnetically coupled to said signal forming means for rejecting all frequencies of said response signals other than those within a predetermined passband; and means operatively responsive to said pass-band frequencies for developing a display signal, the amplitude variations thereof representing the degree of correlation between the recorded data and that represented by said referenced signal.

Claim 12

In a synthetic array data processing system for developing a high resolution display of objects located within an area to be mapped where said system includes coherent radar means operable from a moving craft for providing Doppler shift signals representative of the position of said objects and means for recording said Doppler shift signals on film comprising record scanning means including means for modulating the electron beam thereof with said Doppler shift signal to record same on said film, a cross-cOrrelator device for said processing system comprising, in combination, read scanning means for scanning a plurality of said stored Doppler shift signals for each range successively to develop Doppler history signals for each of said ranges, said read scanning means including means for modulating the electron beam thereof with a reference signal; signal forming means optically coupled to said read scanning means for receiving substantially all of the energy passing through said film from said modulated electron beam to develop a response signal, said film being operatively disposed intermediate said read scanning means and said signal forming means; filter means electromagnetically coupled to said signal forming means for rejecting all frequencies of said response signals other than those within a predetermined passband; and means operatively responsive to said pass-band frequencies for developing a display signal, the amplitude variations thereof representing the degree of correlation between the recorded data and that represented by said referenced signal.

Claim 13

A cross-correlator for processing stored bipolar video data to determine the cross-correlation integral between same and a programmed swept frequency reference signal, said stored data being in the form of film density variations representing Doppler frequency shifts versus time of targets within a predetermined range interval and extending in the range dimensions across a film strip to form a line trace, successive ones of said line traces being spaced-apart in an azimuth direction along said film strip, said cross-correlator comprising, in combination, film transport means for carrying said film strip and including drive means for transferring said film strip to one of two spaced-apart cylinders at a predetermined rate; reading means including a flying spot scanner operatively disposed adjacent to said film transport means for scanning successive range elements in sequence through said range interval, said range elements each comprising a plurality of line traces; means for intensity modulating the electron beam of said flying spot scanner about a fixed bias level, said modulating means including means for generating said programmed swept frequency reference signal, oscillator means for developing a carrier signal, and means for developing a single-side band signal in response to the mixing of said reference and said carrier signals; optical means disposed intermediate one side of said film strip and said reading means for focusing said intensity modulated electron beam onto said film strip when same is scanned; signal forming means including a photomultiplier tube operatively disposed adjacent the other side of said film strip for developing an electrical signal in response to electrons penetrating said film strip; filter means including an output coupled to said signal forming means for rejecting all frequencies of said electrical signal other than those falling within a predetermined pass-band; and means coupled to said output for detecting and summing during each scanning sequence those frequencies of said electrical signal falling within said pass-band to determine said correlation.

Claim 14

A cross-correlator for processing stored bipolar video data to determine the cross-correlation integral between same and a programmed swept frequency reference signal, said stored data being in the form of film density variations representing Doppler frequency shifts versus time of targets within a predetermined range interval and extending in the range dimensions across a film strip to form a line trace, successive ones of said line traces being spaced-apart in an azimuth direction along said film strip, said cross-correlator comprising, in combination, film transport means for carrying said film strip and including drive means for transferring said film strip to one of two spaced-apart cylinders at a predetermined rate; reading means including a flying spot scanner operatively disposed adjacent to said film transport means for scanning successive range elements in sequence through said range interval, said range elements each comprising a plurality of line traces; means for intensity modulating the electron beam of said flying spot scanner about a fixed bias level, said modulating means including means for generating said programmed swept frequency reference signal, oscillator means for developing a carrier signal, and means for developing a single-side band signal in response to the mixing of said reference and said carrier signals; optical means disposed intermediate one side of said film strip and said reading means for focusing said intensity modulated electron beam onto said film strip when same is scanned; signal forming means including a photomultiplier tube operatively disposed adjacent the other side of said film strip for developing an electrical signal in response to electrons penetrating said film strip; filter means including an output coupled to said signal forming means for rejecting all frequencies of said electrical signal other than those falling within a predetermined pass-band; and means coupled to said output for detecting and summing during each scanning sequence those frequencies of said electrical signal falling within said pass-band to determine said correlation.

Claim 15

In a synthetic array data processing system for developing a high resolution display of objects located within an area to be mapped where said system includes coherent radar means operable from a moving craft for providing Doppler shift signals representative of the position of said objects and means for recording said Doppler shift signals on film comprising record scanning means including means for modulating the electron beam thereof with said Doppler shift signal to record same on said film, a cross-correlator device for said processing system comprising, in combination, read scanning means for scanning a plurality of said stored Doppler shift signals for each range successively to develop Doppler history signals for each of said ranges, said read scanning means including means for modulating the Electron beam thereof with a reference signal; signal forming means optically coupled to said read scanning means for receiving substantially all of the light passing through said film to develop a difference signal, said film being operatively disposed intermediate said read scanning means and said signal forming means; filter means electromagnetically coupled to said signal forming means for rejecting all frequencies of said difference signals other than those within a predetermined pass-band; and means operatively responsive to said pass-band frequencies for developing a display signal, the amplitude variations thereof representing the degree of correlation between the recorded data and that represented by said reference signal.

Claim 16

In a synthetic array data processing system for developing a high resolution display of objects located within an area to be mapped where said system includes coherent radar means operable from a moving craft for providing Doppler shift signals representative of the position of said objects and means for recording said Doppler shift signals on film comprising record scanning means including means for modulating the electron beam thereof with said Doppler shift signal to record same on said film, a cross-correlator device for said processing system comprising, in combination, read scanning means for scanning a plurality of said stored Doppler shift signals for each range successively to develop Doppler history signals for each of said ranges, said read scanning means including means for modulating the Electron beam thereof with a reference signal; signal forming means optically coupled to said read scanning means for receiving substantially all of the light passing through said film to develop a difference signal, said film being operatively disposed intermediate said read scanning means and said signal forming means; filter means electromagnetically coupled to said signal forming means for rejecting all frequencies of said difference signals other than those within a predetermined pass-band; and means operatively responsive to said pass-band frequencies for developing a display signal, the amplitude variations thereof representing the degree of correlation between the recorded data and that represented by said reference signal.

Claim 17

The cross-correlator in accordance with Claim 8 wherein said read scanning means further includes means for varying the reference signal frequency as a function of range.

Claim 18

A synthetic array radar mapping system comprising coherent radar means for developing Doppler signals representative of position of an object to be mapped, recording means coupled to said radar means for storing said Doppler signals, reading means including a flying spot scanner coupled to said recording means to develop Doppler history signals, oscillator means coupled to said reading means for developing a frequency varying signal, means for intensity modulating the electron beam of said flying spot scanner with said frequency varying signal, signal forming means disposed adjacent to said reading means and responsive to energy received from said modulated electron beam to develop a correlation signal, filter means coupled to said signal forming means to pass a preselected band of frequencies of said correlation signal, means coupled to said filter means for developing the integral of said correlation signal, and map forming means coupled to said last-mentioned means for developing an indication of the object to be mapped.

Claim 19

A synthetic array radar mapping system comprising coherent radar means for developing Doppler signals representative of position of an object to be mapped, recording means coupled to said radar means for storing said Doppler signals, reading means including a flying spot scanner coupled to said recording means to develop Doppler history signals, oscillator means coupled to said reading means for developing a frequency varying signal, means for intensity modulating the electron beam of said flying spot scanner with said frequency varying signal, signal forming means disposed adjacent to said reading means and responsive to energy received from said modulated electron beam to develop a correlation signal, filter means coupled to said signal forming means to pass a preselected band of frequencies of said correlation signal, means coupled to said filter means for developing the integral of said correlation signal, and map forming means coupled to said last-mentioned means for developing an indication of the object to be mapped.

Claim 20

A synthetic array radar mapping system operable from a craft moving relative to objects in a range interval from the craft comprising a coherent pulsed radar means mounted on the craft for illuminating the objects and receiving Doppler signals therefrom as the craft moves; recording means coupled to said radar means for storing the Doppler signals in the form of successive range traces; reading means including an electron beam for scanning a plurality of range traces in a direction orthogonal thereto in the form of range elements, said plurality defining the length of said synthetic array; means coupled to said reading means including oscillator means for developing a frequency varying signal and means for modulating said electron beam with said frequency varying signal; means coupled to said reading means for deflecting said modulated electron beam to sequentially sample the Doppler history signals stored in each successive range element; signal forming means including a photoelectric device disposed adjacent to said recording means and in axial alignment with said reading means, said photoelectric device being operatively responsive to energy received from said modulated electron beam in the form of intensity modulated light to convert same to an analogous electrical correlation signal; filter means coupled to said photoelectric device for rejecting all frequency components of said correlation signal other than a predetermined band of frequencies; means responsive to said band of frequencies for developing the cross-correlation integral during the time interval said modulated electron beam scans each of said range elements; and display means coupled to said integral developing means for providing an indication of said objects.

Claim 21

A synthetic array radar mapping system operable from a craft moving relative to objects in a range interval from the craft comprising a coherent pulsed radar means mounted on the craft for illuminating the objects and receiving Doppler signals therefrom as the craft moves; recording means coupled to said radar means for storing the Doppler signals in the form of successive range traces; reading means including an electron beam for scanning a plurality of range traces in a direction orthogonal thereto in the form of range elements, said plurality defining the length of said synthetic array; means coupled to said reading means including oscillator means for developing a frequency varying signal and means for modulating said electron beam with said frequency varying signal; means coupled to said reading means for deflecting said modulated electron beam to sequentially sample the Doppler history signals stored in each successive range element; signal forming means including a photoelectric device disposed adjacent to said recording means and in axial alignment with said reading means, said photoelectric device being operatively responsive to energy received from said modulated electron beam in the form of intensity modulated light to convert same to an analogous electrical correlation signal; filter means coupled to said photoelectric device for rejecting all frequency components of said correlation signal other than a predetermined band of frequencies; means responsive to said band of frequencies for developing the cross-correlation integral during the time interval said modulated electron beam scans each of said range elements; and display means coupled to said integral developing means for providing an indication of said objects.

Claim 22

A synthetic array radar processing system for providing focused mapping of objects in a fixed range interval opposite a moving craft in response to Doppler signals recorded on an intermediate film strip in the form of line traces of film density variations extending in the range dimensiOn across said film strip, the frequency and time occurrence of said Doppler signals and of said film density variations being representative of positions of said objects resolvable within said range interval, said radar processing system comprising reading means including a flying spot scanner operatively disposed adjacent said film strip for sequentially scanning a plurality of said line traces in the form of successive range elements through said range interval to develop corresponding Doppler history signals; means for intensity modulating the electron beam of said flying spot scanner with a linearly varying frequency signal about a fixed bias level as said electron beam scans each range element, said modulated means including a voltage controlled swept oscillator for developing said linearly varying frequency signal, a variable gain amplifier for developing a time varying control voltage to drive said swept oscillator and sweep generators for deflecting said modulated electron beam and for driving said variable gain amplifier to develop said control voltage; signal forming means including a photomultiplier tube operatively disposed adjacent said film strip on a side thereof opposite said reading means and in axial alignment therewith to receive that energy from said modulated electron beam which penetrates said film strip in the form of intensity modulated light, said photomultiplier tube developing in response to said light an electrical correlation signal representative of the cross-correlation function between said linearly varying frequency function and the Doppler history signal for the respective range element; filter means coupled to said signal forming means rejecting all frequency components of said electrical correlation signal other than a predetermined pass-band; means coupled to said filter means and responsive to said pass-band of frequencies for developing the integral thereof over the time interval said modulated electron beam scans each range element; and display means coupled to said last-mentioned means to provide an indication of said objects.

Claim 23

A synthetic array radar processing system for providing focused mapping of objects in a fixed range interval opposite a moving craft in response to Doppler signals recorded on an intermediate film strip in the form of line traces of film density variations extending in the range dimensiOn across said film strip, the frequency and time occurrence of said Doppler signals and of said film density variations being representative of positions of said objects resolvable within said range interval, said radar processing system comprising reading means including a flying spot scanner operatively disposed adjacent said film strip for sequentially scanning a plurality of said line traces in the form of successive range elements through said range interval to develop corresponding Doppler history signals; means for intensity modulating the electron beam of said flying spot scanner with a linearly varying frequency signal about a fixed bias level as said electron beam scans each range element, said modulated means including a voltage controlled swept oscillator for developing said linearly varying frequency signal, a variable gain amplifier for developing a time varying control voltage to drive said swept oscillator and sweep generators for deflecting said modulated electron beam and for driving said variable gain amplifier to develop said control voltage; signal forming means including a photomultiplier tube operatively disposed adjacent said film strip on a side thereof opposite said reading means and in axial alignment therewith to receive that energy from said modulated electron beam which penetrates said film strip in the form of intensity modulated light, said photomultiplier tube developing in response to said light an electrical correlation signal representative of the cross-correlation function between said linearly varying frequency function and the Doppler history signal for the respective range element; filter means coupled to said signal forming means rejecting all frequency components of said electrical correlation signal other than a predetermined pass-band; means coupled to said filter means and responsive to said pass-band of frequencies for developing the integral thereof over the time interval said modulated electron beam scans each range element; and display means coupled to said last-mentioned means to provide an indication of said objects.

Claim 24

A synthetic array radar mapping system for providing focused mapping of objects in a range interval opposite a moving craft comprising coherent side-looking radar means having an antenna mounted on the side of said craft for illuminating objects disposed within said range interval with a pulsed radio frequency carrier and for obtaining Doppler returns from those objects illuminated, said Doppler returns varying in frequency and having a zero frequency whenever a resolvable object is opposite said craft; oscillator means coupled to said radar means for frequency offsetting said Doppler returns so that said zero frequency is at a selected frequency; an intermediate storage film including means for moving said film at a predetermined velocity; a record scanning tube coupled to said radar means and to said offset oscillator means, said record scanning tube including an electron beam; gate means coupled to said radar means and to said record scanning tube for sweeping the electron beam thereof across said film in range synchronism with said Doppler returns; means including biasing means coupled to said record scanning tube for intensity modulating the electron beam thereof in accordance with the instantaneous amplitude of said Doppler returns; means for imaging onto said storage film energy in the form of intensity modulated light in accordance with said modulated electron beam in the form of successive parallel range traces; a read scanning tube mounted adjacent to said storage film and including an electron beam; sweep generator means coupled to said read scanning tube for developing first and second sweep signals, the electron beam of said read scanning tube being deflected according to range by said first sweep signal to sequentially scan a portion of said range trace recordings in a direction such that all targets of the same range are scanned successively forming successive range elementS, the electron beam of said read scanning tube also being deflected in the range dimension one range resolution after scanning each of said range elements, said first and second sweep signals being further combined so that said read scanning beam sequentially sweeps through successive reading frames each comprising a like number of range traces forming said scanned portions, the scanning of successive frames being commenced in response to the scanning of that range element of the previous reading frame which represents the farthest range; variable gain amplifier for developing a linearly varying voltage in response to said first sweep signal, said amplifier including means for varying the slope of said varying voltage as a function of range in response to said second sweep signal; voltage controlled swept oscillator coupled to said read scanning tube for intensity modulating the electron beam thereof with a reference signal comprising linearly varying frequency in response to said voltage from said amplifier; photomultiplier means mounted adjacent to said intermediate storage film in axial alignment with said read scanning tube for receiving energy from the modulated electron beam thereof in the form of intensity modulated light penetrating said film during each range element, said photomultiplier means being responsive to said light for developing correlation signals having frequency components related to the scanned portion of said stored Doppler returns, said correlation signals including frequencies equal to the difference between said stored Doppler returns and the reference signal modulating said read electron beam; filter means coupled to said photomultiplier means and adapted to pass said difference frequencies; detecting means coupled to said filter means for developing a signal representative of the envelope of said correlation signal passed by said filter; integrating means for developing an integral of said detected signal; a display scanning tube having an electron beam and coupled to said sweep generating means for deflecting said display electron beam in the range dimension in accordance with said second sweep signal, said display scanning tube also further coupled to said integrating means for intensity modulating the display electron beam in accordance with said integral; and a movable map film mounted adjacent to said display scanning tube and coupled to said intermediate storage film, said movable map film being adapted to move at a speed proportional to said intermediate storage film and responding to energy in the form of intensity modulated light emitting from said display electron beam to provide a focused indication of said objects being mapped.

Claim 25

A synthetic array radar mapping system for providing focused mapping of objects in a range interval opposite a moving craft comprising coherent side-looking radar means having an antenna mounted on the side of said craft for illuminating objects disposed within said range interval with a pulsed radio frequency carrier and for obtaining Doppler returns from those objects illuminated, said Doppler returns varying in frequency and having a zero frequency whenever a resolvable object is opposite said craft; oscillator means coupled to said radar means for frequency offsetting said Doppler returns so that said zero frequency is at a selected frequency; an intermediate storage film including means for moving said film at a predetermined velocity; a record scanning tube coupled to said radar means and to said offset oscillator means, said record scanning tube including an electron beam; gate means coupled to said radar means and to said record scanning tube for sweeping the electron beam thereof across said film in range synchronism with said Doppler returns; means including biasing means coupled to said record scanning tube for intensity modulating the electron beam thereof in accordance with the instantaneous amplitude of said Doppler returns; means for imaging onto said storage film energy in the form of intensity modulated light in accordance with said modulated electron beam in the form of successive parallel range traces; a read scanning tube mounted adjacent to said storage film and including an electron beam; sweep generator means coupled to said read scanning tube for developing first and second sweep signals, the electron beam of said read scanning tube being deflected according to range by said first sweep signal to sequentially scan a portion of said range trace recordings in a direction such that all targets of the same range are scanned successively forming successive range elementS, the electron beam of said read scanning tube also being deflected in the range dimension one range resolution after scanning each of said range elements, said first and second sweep signals being further combined so that said read scanning beam sequentially sweeps through successive reading frames each comprising a like number of range traces forming said scanned portions, the scanning of successive frames being commenced in response to the scanning of that range element of the previous reading frame which represents the farthest range; variable gain amplifier for developing a linearly varying voltage in response to said first sweep signal, said amplifier including means for varying the slope of said varying voltage as a function of range in response to said second sweep signal; voltage controlled swept oscillator coupled to said read scanning tube for intensity modulating the electron beam thereof with a reference signal comprising linearly varying frequency in response to said voltage from said amplifier; photomultiplier means mounted adjacent to said intermediate storage film in axial alignment with said read scanning tube for receiving energy from the modulated electron beam thereof in the form of intensity modulated light penetrating said film during each range element, said photomultiplier means being responsive to said light for developing correlation signals having frequency components related to the scanned portion of said stored Doppler returns, said correlation signals including frequencies equal to the difference between said stored Doppler returns and the reference signal modulating said read electron beam; filter means coupled to said photomultiplier means and adapted to pass said difference frequencies; detecting means coupled to said filter means for developing a signal representative of the envelope of said correlation signal passed by said filter; integrating means for developing an integral of said detected signal; a display scanning tube having an electron beam and coupled to said sweep generating means for deflecting said display electron beam in the range dimension in accordance with said second sweep signal, said display scanning tube also further coupled to said integrating means for intensity modulating the display electron beam in accordance with said integral; and a movable map film mounted adjacent to said display scanning tube and coupled to said intermediate storage film, said movable map film being adapted to move at a speed proportional to said intermediate storage film and responding to energy in the form of intensity modulated light emitting from said display electron beam to provide a focused indication of said objects being mapped.