Cubesat infrared atmospheric sounder (CIRAS)

A spectrometer, comprising:

• a slit having a first length and first width;
• a diffraction grating;
• a two dimensional (2D) focal plane array electromagnetically coupled to the diffraction grating, the 2D focal plane array comprising an array of pixels including a plurality of groups of the pixels, each of the groups having a second width in a first direction and a second length in a second direction, wherein the second length of the groups of pixels is aligned with and parallel to the first length of the slit;
• a mirror collecting electromagnetic radiation in one or more fields of view;
• a telescope positioned between the slit and the mirror, the telescope imaging one or more areas in the one or more fields of view on the slit;
• a collimator between the slit and the diffraction grating, wherein the collimator collimates the electromagnetic radiation transmitted through the slit;
• an imager;
• and
• an actuator connected to the mirror, the actuator rotating the mirror and scanning the one or more fields of view inputted onto the mirror over one or more regions of a planet's atmosphere or surface, wherein the rotating scans the one or more fields of view in a cross-track direction comprising the first direction perpendicular to the second direction, and wherein the second direction is (1) parallel to the first length of the slit and (2) parallel to a third direction of movement of the spectrometer or a vehicle including the spectrometer;
• and
• wherein:
• the slit transmits the electromagnetic radiation received on the slit, the electromagnetic radiation comprising a plurality of bands of wavelengths,
• the diffraction grating diffracts the electromagnetic radiation transmitted through the slit into a plurality of beams,
• each of the beams comprise a portion of the electromagnetic radiation comprising a different one of the bands of the wavelengths,
• the imager images each of the beams onto the 2D focal plane array, and
• each of the beams are transmitted onto a different one of the groups of the pixels.

A method of making a spectrometer, comprising:

• positioning a slit having a first length and first width;
• positioning a diffraction grating;
• electromagnetically coupling a two dimensional (2D) focal plane array to the diffraction grating, the 2D focal plane array comprising an array of pixels including a plurality of groups of the pixels, each of the groups having a second width in a first direction and a second length in a second direction, wherein the second length of the groups of pixels is aligned with and parallel to the first length of the slit;
• positioning a mirror collecting electromagnetic radiation in one or more fields of view;
• positioning a telescope between the slit and the mirror, the telescope imaging one or more areas in the one or more fields of view on the slit;
• positioning a collimator between the slit and the diffraction grating, wherein the collimator collimates the electromagnetic radiation transmitted through the slit;
• and
• positioning an imager;
• wherein:
• the slit transmits the electromagnetic radiation received on the slit, the electromagnetic radiation comprising a plurality of bands of wavelengths,
• the diffraction grating diffracts the electromagnetic radiation transmitted through the slit into a plurality of beams,
• each of the beams comprise a portion of the electromagnetic radiation comprising a different one of the bands of the wavelengths,
• the imager images each of the beams onto the 2D focal plane array,
• each of the beams are transmitted onto a different one of the groups of the pixels, and
• the slit, the mirror, the telescope, the collimator, the imager, and the diffraction grating are sized and positioned so that at least one of:
• the spectrometer fits inside a volume of 25 centimeters by 25 centimeter by 15 centimeters, or
• the spectrometer fits inside an unmanned aerial vehicle, a CubeSat, a drone, or a portable computer or communications device.