Multi-slit configured hyperspectral imager
Systems and methods relating to a multi-slit hyperspectral imager. The imager is configured with multiple slits that are parallel to one another. Each slit produces its own hyperspectral cube and is limited to a specific wavelength range. The multiple slits produce multiple data sets, obtained in quick succession, for the same section of an area to be imaged. In optical spectrometry applications such as trace gas sensing and quantification, this allows for improved measurement precision. The imager may be used for any gas of interest by adjusting the wavelength range to one that contains absorption features of the targeted gas.
1. A hyperspectral imager comprising:
a plurality of slit apertures such that a specific portion of a scene is imaged multiple times through said plurality of slit apertures as a platform on which said imager is mounted traverses said scene;
at least one collimating lens through which images of said specific portion of said scene passes through after being received through at least one of said plurality of slit apertures;
at least one spectrally dispersive element through which images of said specific portion of said scene passes through after passing through said at least one collimating lens;
at least one imaging system for refocusing said images of said specific portion of said scene on to a focal plane pixel array; and
a plurality of pixels on said focal plane pixel array for receiving said images of said specific portion of said scene,
wherein
each slit aperture produces a hyperspectral dataset corresponding to a limited number of specific wavelengths of light received through said slit aperture, said imager configured to produce a plurality of hyperspectral datasets equal in number to a number of said plurality of slit apertures, wherein each of said plurality of hyperspectral datasets forms a section of a separate hyperspectral datacube; and
each of said plurality of hyperspectral datasets covers an entirety of said specific portion of said scene;
said imager further configured to produce a plurality of hyperspectral datacubes, after said scene is imaged, wherein each of said plurality of hyperspectral datacubes is produced by a different slit aperture; and
each slit aperture corresponds to a fixed number of n pixels of said plurality of pixels such that n<m, where m is a maximum number of available pixels.
2. The imager according to claim 1 , wherein said spectrally dispersive element is a grating.
3. The imager according to claim 1 , wherein said spectrally dispersive element is a prism.
4. The imager according to claim 1 , wherein said slit apertures are evenly spaced apart from one another.
5. The imager according to claim 1 , wherein said slit apertures are parallel to each other in a slit plane.
6. The imager according to claim 1 , wherein said plurality of slit apertures are normal to a direction of travel of said platform.
7. The imager according to claim 1 , wherein said specific wavelengths of light include absorption wavelengths of a specific gas.
8. The imager according to claim 7 , wherein said specific gas is methane.
9. A hyperspectral imager comprising:
a plurality of parallel slit apertures such that a specific portion of a scene is imaged multiple times through said plurality of slit apertures as a platform on which said imager is mounted traverses said scene; and
a plurality of pixels for receiving split light on a focal plane, said split light resulting from light received through at least one of said plurality of slit apertures,
wherein
each slit aperture produces a hyperspectral dataset corresponding to a limited number of specific wavelengths of light received through said slit aperture, said imager configured to produce a plurality of hyperspectral datasets equal in number to a number of said plurality of slit apertures;
each of said plurality of hyperspectral datasets covers an entirety of said specific portion of said scene; and
said imager further configured to produce a plurality of hyperspectral datacubes, after said scene is imaged, wherein each of said plurality of hyperspectral datacubes is produced by a different slit aperture.
10. The imager according to claim 9 , wherein each slit aperture corresponds to a fixed number of n pixels of said plurality of pixels, n being less than a maximum number of available pixels.