Imaging spectroradiometer

Claim 2

An imaging spectroradiometer, comprising: a light collector, including a lens which produces a two-dimensional viewed image of a scene, means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of wavelengths, the means for spectrally filtering including means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, and means for scanning a filter window of a preselected wavelength transmission across the scene during each repetition, and a detector which receives the image of the preselected spectrum of wavelengths from the means for spectrally filtering and produces an electronic signal of an amplitude of each of a plurality of pixels, and wherein the detector electronically scans a detection gate window across the scene in synchronization with the scanning of the filter window; and an image processor operating substantially in real time, comprising a memory which temporarily stores the electronic signals produced by the detector as a plurality of pixelated electronic images, each image corresponding to an amplitude of the scene viewed at one of the preselected wavelengths, means for correcting the amplitudes of the pixels of the electronic images responsive to preselected systematic sources of error and means for calibrating the amplitudes responsive to the properties of the light collector, producing a corrected and calibrated electronic image, and means for correlating the corrected and calibrated electronic image with a preselected response function to produce an electronic image of a preselected spectral characteristic.

Claim 3

The spectroradiometer of claim 1, wherein the means for repeating of the means for spectrally filtering operates at a repetition frequency of at least about 20 cycles per second, on a repeating sequence of at least about 20 spectral images.

Claim 4

The spectroradiometer of claim 1, wherein the means for spectrally filtering includes a circularly variable filter and the means for repeating includes a motor which drives the rotation of the circularly variable filter.

Claim 5

The spectroradiometer of claim 3, wherein the circularly variable filter is continuously variable.

Claim 6

The spectroradiometer of claim 1, wherein the preselected range of wavelengths of the means for spectrally filtering is in the infrared, and wherein the detector is an infrared detector.

Claim 7

The spectroradiometer of claim 1, wherein the detector comprises an array of sensor elements, each sensor element corresponding to a single pixel.

Claim 8

The spectroradiometer of claim 1, wherein the memory comprises a first memory region and a second memory region, and wherein the spectroradiometer further comprises memory control means for storing pixelated electronic images in the first memory while simultaneously recalling pixelated electronic images from the second memory and providing the recalled pixelated electronic images to the means for correcting.

Claim 9

The spectroradiometer of claim 1, wherein the means for correcting includes means for adding a dark field correction value on a pixel-by-pixel basis to the pixelated electronic image.

Claim 10

The spectroradiometer of claim 1, wherein the means for calibrating includes means for scaling the pixelated electronic image on a pixel-by-pixel basis.

Claim 11

The spectroradiometer of claim 1, wherein the image processor is synchronized to the means for repeating, so that the output of the image processor is in real time at the repetition rate of the means for repeating.

Claim 12

The spectroradiometer of claim 1, wherein the means for correlating includes a hardware multiplier/accumulator having as a first multiplier input the spectral image at a pixel and as a second multiplier input the preselected spectral response function, and as an output the sum of the products of the first and second multiplier inputs for the preselected wavelengths.

Claim 13

The spectroradiometer of claim 1, further including means for preventing radiation, other than that passing through the means for spectrally filtering, from reaching the detector.

Claim 14

The spectroradiometer of claim 1, further including a cooled vacuum dewar containing the detector, and wherein the detector is positioned so closely adjacent to the means for spectrally filtering that substantially the only energy reaching the detector is that passing through the spectral filter and that emitted by the detector and reflected from the spectral filter back to the detector.

Claim 15

An imaging spectroradiometer, comprising: a light collector, including a lens which produces a two-dimensional viewed image of a scene, means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of wavelengths, wherein the means for repeating of the means for spectrally filtering operates at a repetition frequency of at least about 20 cycles per second, on a repeating sequence of at least about 20 spectral images, the means for spectrally filtering including means for sequentially producing a sequence of filtered images of an entire scene at a sequence of wavelengths, and means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, and a detector which receives the sequence of filtered images from the means for sequentially producing produces an electronic signal of an amplitude of each of a plurality of pixels of the scene; an image processor operating substantially in real time, comprising a memory which temporarily stores the electronic signals produced by the detector as a plurality of pixelated electronic images, each image corresponding to an amplitude of the scene viewed at one of the preselected wavelengths, means for correcting the amplitudes of the pixels of the electronic images responsive to preselected systematic sources of error and means for calibrating the amplitudes responsive to the properties of the light collector, producing a corrected and calibrated electronic image, and means for correlating the corrected and calibrated electronic image with a preselected response function to produce an electronic image of a preselected spectral characteristic.

Claim 16

An imaging spectroradiometer, comprising: a light collector, including a lens which produces a two-dimensional viewed image of a scene, means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of wavelengths, wherein the means for repeating of the means for spectrally filtering operates at a repetition frequency of at least about 20 cycles per second, on a repeating sequence of at least about 20 spectral images, the means for spectrally filtering including means for sequentially producing a sequence of filtered images of an entire scene at a sequence of wavelengths, and means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, and a detector which receives the sequence of filtered images from the means for sequentially producing produces an electronic signal of an amplitude of each of a plurality of pixels of the scene; an image processor operating substantially in real time, comprising a memory which temporarily stores the electronic signals produced by the detector as a plurality of pixelated electronic images, each image corresponding to an amplitude of the scene viewed at one of the preselected wavelengths, means for correcting the amplitudes of the pixels of the electronic images responsive to preselected systematic sources of error and means for calibrating the amplitudes responsive to the properties of the light collector, producing a corrected and calibrated electronic image, and means for correlating the corrected and calibrated electronic image with a preselected response function to produce an electronic image of a preselected spectral characteristic.

Claim 17

The spectroradiometer of claim 14, wherein the means for sequentially producing includes a circularly variable filter formed of a plurality of discrete filter elements and the means for repeating includes a motor which drives the rotation of the circularly variable filter.

Claim 18

The spectroradiometer of claim 14, wherein the preselected range of wavelengths of the means for spectrally filtering is in the infrared, and wherein the detector is an infrared detector.

Claim 19

An imaging spectroradiometer, comprising: a light collector, including a lens which produces a two-dimensional viewed image of a scene, means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of wavelengths, the means for spectrally filtering including means for sequentially producing a sequence of filtered images of an entire scene at a sequence of wavelengths, and means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, a detector which receives the sequence of filtered images from the means for sequentially producing produces an electronic signal of an amplitude of each of a plurality of pixels of the scene; and means for preventing radiation, other than that passing through the means for spectrally filtering, from reaching the detector; an image processor operating substantially in real time, comprising a memory which temporarily stores the electronic signals produced by the detector as a plurality of pixelated electronic images, each image corresponding to an amplitude of the scene viewed at one of the preselected wavelengths, means for correcting the amplitudes of the pixels of the electronic images responsive to preselected systematic sources of error and means for calibrating the amplitudes responsive to the properties of the light collector, producing a corrected and calibrated electronic image, and means for correlating the corrected and calibrated electronic image with a preselected response function to produce an electronic image of a preselected spectral characteristic.

Claim 20

An imaging spectroradiometer, comprising: a light collector, including a lens which produces a two-dimensional viewed image of a scene, means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of wavelengths, the means for spectrally filtering including means for sequentially producing a sequence of filtered images of an entire scene at a sequence of wavelengths, and means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, a detector which receives the sequence of filtered images from the means for sequentially producing produces an electronic signal of an amplitude of each of a plurality of pixels of the scene; and means for preventing radiation, other than that passing through the means for spectrally filtering, from reaching the detector; an image processor operating substantially in real time, comprising a memory which temporarily stores the electronic signals produced by the detector as a plurality of pixelated electronic images, each image corresponding to an amplitude of the scene viewed at one of the preselected wavelengths, means for correcting the amplitudes of the pixels of the electronic images responsive to preselected systematic sources of error and means for calibrating the amplitudes responsive to the properties of the light collector, producing a corrected and calibrated electronic image, and means for correlating the corrected and calibrated electronic image with a preselected response function to produce an electronic image of a preselected spectral characteristic.

Claim 21

An imaging spetroradiometer, comprising: a light collector, including a lens which produces a two-dimensional viewed image of a scene, means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of wavelengths, the means for spectrally filtering including means for sequentially producing a sequence of filtered images of an entire scene at a sequence of wavelengths, and means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, a detector which receives the sequence of filtered images from the means for sequentially producing produces an electronic signal of an amplitude of each of a plurality of pixels of the scene; and a cooled vacuum dewar containing the detector, and wherein the detector is positioned so closely adjacent to the means for spectrally filtering that substantially the only energy reaching the detector is that passing through the spectral filter and that emitted by the detector and reflected from the spectral filter back to the detector; an image processor operating substantially in real time, comprising a memory which temporarily stores the electronic signal produced by the detector as a plurality of pixelated electronic images, each image corresponding to an amplitude of the scene viewed at one of the preselected wavelengths, means for correcting the amplitudes of the pixels of the electronic image responsive to preselected systematic sources of error and means for calibrating the amplitudes responsive to the properties of the light collector, producing a corrected and calibrated electronic image, and means for correlating the corrected and calibrated electronic image with a preselected response function to produce an electronic image of a preselected spectral characteristic.

Claim 22

An imaging spetroradiometer, comprising: a light collector, including a lens which produces a two-dimensional viewed image of a scene, means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of wavelengths, the means for spectrally filtering including means for sequentially producing a sequence of filtered images of an entire scene at a sequence of wavelengths, and means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, a detector which receives the sequence of filtered images from the means for sequentially producing produces an electronic signal of an amplitude of each of a plurality of pixels of the scene; and a cooled vacuum dewar containing the detector, and wherein the detector is positioned so closely adjacent to the means for spectrally filtering that substantially the only energy reaching the detector is that passing through the spectral filter and that emitted by the detector and reflected from the spectral filter back to the detector; an image processor operating substantially in real time, comprising a memory which temporarily stores the electronic signal produced by the detector as a plurality of pixelated electronic images, each image corresponding to an amplitude of the scene viewed at one of the preselected wavelengths, means for correcting the amplitudes of the pixels of the electronic image responsive to preselected systematic sources of error and means for calibrating the amplitudes responsive to the properties of the light collector, producing a corrected and calibrated electronic image, and means for correlating the corrected and calibrated electronic image with a preselected response function to produce an electronic image of a preselected spectral characteristic.

Claim 23

An imaging spectroradiometer, comprising: an energy collector, including means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of X-ray wavelengths, the means for spectrally filtering including means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, and means for scanning a filter window of a preselected wavelength transmission across the scene during each repetition; a normally closed gate which receives the sequence of spectrally filtered images from the means for spectrally filtering and controllably opens at a preselected time to pass an image of a preselected wavelength from the sequence of spectral images, means for detecting X-rays received from the gate, the means for detecting including a detector which receives the X-rays from the gate and produces an electronic signal of an amplitude at each of a plurality of pixels; and an image processor.

Claim 24

An imaging spectroradiometer, comprising: an energy collector, including means for spectrally filtering a repeating sequence of spectral images from the viewed image over a preselected spectrum of X-ray wavelengths, the means for spectrally filtering including means for repeating the spectral imaging of the scene over the preselected spectrum at a preselected sequence repetition frequency, and means for scanning a filter window of a preselected wavelength transmission across the scene during each repetition; a normally closed gate which receives the sequence of spectrally filtered images from the means for spectrally filtering and controllably opens at a preselected time to pass an image of a preselected wavelength from the sequence of spectral images, means for detecting X-rays received from the gate, the means for detecting including a detector which receives the X-rays from the gate and produces an electronic signal of an amplitude at each of a plurality of pixels; and an image processor.

Claim 25

The spectroradiometer of claim 19, wherein the image processor comprises a memory which temporarily stores the electronic signals produced by the detector as a plurality of pixelated electronic images, each image corresponding to an amplitude of the scene viewed at one of the preselected wavelengths, means for correcting the amplitudes of the pixels of the electronic images responsive to preselected systematic sources of error and means for calibrating the amplitudes responsive to the properties of the energy collector, producing a corrected and calibrated electronic image, and means for correlating the corrected and calibrated electronic image with a preselected response function to produce an electronic image of a preselected spectral characteristic.