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US6088086A Expired / Lapsed US ⏱️ 0.0 years remaining

Range determination for scannerless imaging

Assignee: National Technology and Engineering Solutions of Sandia LLC
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Filing: 1995-09-11
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Granted: 2000-07-11
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Expires: 2015-09-11
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Abstract

Abstract A new method of operating a scannerless range imaging system (e.g., a scannerless laser radar) has been developed. This method is designed to compensate for nonlinear effects which appear in many real-world components. The system operates by determining the phase shift of the laser modulation, which is a physical quantity related physically to the path length between the laser source and the detector, for each pixel of an image.

Inventors

  • 👤 Maritza Rosa Muguira
  • 👤 John Theodore Sackos
  • 👤 Bart Davis Bradley
  • 👤 Robert Nellums

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 13:23
CPC Classifications
G; G01; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/08; G01S17/32; G01S17/36; G01S17/88; G01S17/89; G01S17/894; G01S7/00; G01S7/48; G01S7/491; G01S7/4912; G01S7/493

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 310 words
A method for operating a Scott-type scannerless imaging laser radar, said laser radar comprising a transmitted beam, a target, and a ranging receiver comprising a detector means having n pixels, modulation means comprising an image intensifier whose gain is controlled by an image intensifier control voltage, and a range processor, the method comprising: i) modulating the transmitted beam power periodically; ii) illuminating the target with the transmitted beam; iii) detecting a reflection of the transmitted beam from the target using the ranging receiver; iv) measuring a charge A n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated in phase with the transmitted beam; v) measuring a charge B n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated 90 degrees out of phase with the transmitted beam; vi) measuring a charge C n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated 180 degrees out of phase with the transmitted beam; vii) measuring a charge D n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated 270 degrees out of phase with the transmitted beam, and; viii) determining range to the target by extracting from the integrated charges A n , B n , C n , and D n a round trip phase shift φ n for each of the n pixels of the detector means of the ranging receiver.
Claim 2
Independent Claim 310 words
A method for operating a Scott-type scannerless imaging laser radar, said laser radar comprising a transmitted beam, a target, and a ranging receiver comprising a detector means having n pixels, modulation means comprising an image intensifier whose gain is controlled by an image intensifier control voltage, and a range processor, the method comprising: i) modulating the transmitted beam power periodically; ii) illuminating the target with the transmitted beam; iii) detecting a reflection of the transmitted beam from the target using the ranging receiver; iv) measuring a charge A n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated in phase with the transmitted beam; v) measuring a charge B n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated 90 degrees out of phase with the transmitted beam; vi) measuring a charge C n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated 180 degrees out of phase with the transmitted beam; vii) measuring a charge D n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated 270 degrees out of phase with the transmitted beam, and; viii) determining range to the target by extracting from the integrated charges A n , B n , C n , and D n a round trip phase shift φ n for each of the n pixels of the detector means of the ranging receiver.
Claim 3
Dependent Claim 29 words
The method of claim 1, wherein the periodic modulation of the transmitted beam and the periodic modulation of the image intensifier control voltage have substantially the same functional form.
Claim 4
Dependent Claim 15 words
The method of claim 2, wherein the periodic modulation of the transmitted beam is sinusoidal.
Claim 5
Independent Claim 214 words
A method for operating a Scott-type scannerless imaging laser radar, said laser radar comprising a transmitted beam, a target, and a ranging receiver comprising a detector means having n pixels, modulation means comprising an image intensifier whose gain is controlled by an image intensifier control voltage, and a range processor, the method comprising: i) modulating the transmitted beam power periodically; ii) illuminating the target with the transmitted beam; iii) detecting a reflection of the transmitted beam from the target using the ranging receiver; iv) measuring a charge A n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is held at a fixed level providing a non-zero image intensifier gain G 0 ; v) measuring a charge B n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated in phase with the transmitted beam, and; vi) determining range to the target by extracting from the integrated charges A n and B n a round trip phase shift φ n for each of the n pixels of the detector means of the ranging receiver.
Claim 6
Independent Claim 214 words
A method for operating a Scott-type scannerless imaging laser radar, said laser radar comprising a transmitted beam, a target, and a ranging receiver comprising a detector means having n pixels, modulation means comprising an image intensifier whose gain is controlled by an image intensifier control voltage, and a range processor, the method comprising: i) modulating the transmitted beam power periodically; ii) illuminating the target with the transmitted beam; iii) detecting a reflection of the transmitted beam from the target using the ranging receiver; iv) measuring a charge A n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is held at a fixed level providing a non-zero image intensifier gain G 0 ; v) measuring a charge B n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is periodically modulated in phase with the transmitted beam, and; vi) determining range to the target by extracting from the integrated charges A n and B n a round trip phase shift φ n for each of the n pixels of the detector means of the ranging receiver.
Claim 7
Dependent Claim 22 words
The method of claim 4, wherein the periodic modulation of both the transmitted beam and the image intensifier control voltage is sinusoidal.
Claim 8
Dependent Claim 41 words
The method of claim 4, wherein the periodic modulation of both the transmitted beam and the image intensifier control voltage is square wave modulated, yielding an image intensifier gain which varies essentially discontinuously between G 0 and a second gain value.
Claim 9
Dependent Claim 20 words
The method of claim 6, wherein the modulation depth of the square wave modulation of the transmitted beam is 100%.
Claim 10
Dependent Claim 18 words
The method of claim 6, wherein the second gain value of the image intensifier gain is zero gain.
Claim 11
Independent Claim 343 words
A method for operating a Scott-type scannerless imaging laser radar, said laser radar comprising a transmitted beam, a target, and a ranging receiver comprising a detector means having n pixels, modulation means comprising an image intensifier whose gain is controlled by an image intensifier control voltage to be either high or low, and a range processor, the method comprising: i) modulating the transmitted beam power with a square wave component; ii) illuminating the target with the transmitted beam; iii) detecting a reflection of the transmitted beam from the target using the ranging receiver; iv) measuring a charge A n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is square wave modulated between high and low values in phase with the transmitted beam; v) measuring a charge B n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is square wave modulated between high and low values 90 degrees out of phase with the transmitted beam; vi) measuring a charge C n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is square wave modulated between high and low values 180 degrees out of phase with the transmitted beam; vii) measuring a charge D n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is square wave modulated between high and low values 270 degrees out of phase with the transmitted beam; viii) determining range to the target by extracting from the integrated charges A n , B n , C n , and D n a round trip phase shift φ n for each of the n pixels of the detector means of the ranging receiver.
Claim 12
Independent Claim 343 words
A method for operating a Scott-type scannerless imaging laser radar, said laser radar comprising a transmitted beam, a target, and a ranging receiver comprising a detector means having n pixels, modulation means comprising an image intensifier whose gain is controlled by an image intensifier control voltage to be either high or low, and a range processor, the method comprising: i) modulating the transmitted beam power with a square wave component; ii) illuminating the target with the transmitted beam; iii) detecting a reflection of the transmitted beam from the target using the ranging receiver; iv) measuring a charge A n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is square wave modulated between high and low values in phase with the transmitted beam; v) measuring a charge B n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is square wave modulated between high and low values 90 degrees out of phase with the transmitted beam; vi) measuring a charge C n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is square wave modulated between high and low values 180 degrees out of phase with the transmitted beam; vii) measuring a charge D n at each of the n pixels of the detector means of the ranging receiver integrated over an integral number of modulation cycles while the image intensifier control voltage is square wave modulated between high and low values 270 degrees out of phase with the transmitted beam; viii) determining range to the target by extracting from the integrated charges A n , B n , C n , and D n a round trip phase shift φ n for each of the n pixels of the detector means of the ranging receiver.
Claim 13
Dependent Claim 20 words
The method of claim 9, wherein the modulation depth of the square wave modulation of the transmitted beam is 100%.
Claim 14
Dependent Claim 17 words
The method of claim 9, wherein the low gain level of the image intensifier is zero gain.

References Cited (Backward Citations)

US4935616A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2003-07-11 2004-01-10 2004-07-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2007-07-11 2008-01-10 2008-07-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2011-07-11 2012-01-10 2012-07-11 $7700.00 Window Closed / Lapsed

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