Abstract:
An optical sensor assembly in which a four axis gimbal and dual coelostat mirror configuration provide pointing of the sensor line of sight in azimuth and elevation, stabilized for platform pitch. One example of a sensor system includes a first optical sub-system including a first plurality of optical elements, and a second optical sub-system configured to rotate about a first axis relative to the first optical sub-system. The second optical sub-system includes afocal foreoptics configured to direct a collimated beam of electromagnetic radiation to the first optical sub-system, a first coelostat minor configured to rotate about a second axis substantially perpendicular to the first axis, and a second coelostat mirror configured to rotate about a third axis substantially perpendicular to both the first axis and the second axis, and to receive electromagnetic radiation reflected by the first coelostat minor and to direct the electromagnetic radiation to the afocal foreoptics.
Abstract:
A multi-band refractive optical imaging system. In one example, the system includes a plurality of lenses configured to receive and propagate electromagnetic radiation in at least the visible spectral band and the longwave infrared (LWIR) spectral band, the plurality of lenses including a first group of lenses of a first crown material, at least one lens of a first flint material, and at least one lens of a second material different than the first crown material and the first flint material. The plurality of lenses includes at least one crown-flint pair configured as an achromat to provide color correction in the visible and/or LWIR spectral bands. The system also includes a first beamsplitter configured to separate the electromagnetic radiation into the visible spectral band and the LWIR spectral band, and a rear external aperture stop positioned between the plurality of lenses and the first beamsplitter.
Abstract:
Methods and apparatus for sensor calibration of a system having an aperture, primary mirror, secondary mirror, and a sensor, such as an FPA IR sensor. A calibration system includes calibration energy sources with a movable first mirror configured to be selectively inserted into the optical path and select one of the calibration energy sources and a second mirror configured to image the selected calibration energy source.
Abstract:
An optical sensor system includes a primary mirror configured to receive electromagnetic radiation from the objects, a secondary mirror configured to receive the electromagnetic radiation reflected from the primary mirror, and a tertiary mirror configured to receive the electromagnetic radiation reflected from the secondary mirror. The system further includes a dichroic beamsplitter configured to direct electromagnetic radiation from a first spectrum along a first axis and to direct electromagnetic radiation from a second spectrum along a second axis. The system further includes a first image plane configured to receive the electromagnetic radiation from the first spectrum along the first axis to form a first image of the objects and a second image plane configured to receive the electromagnetic radiation from the second spectrum along the second axis to form a second image of the objects.
Abstract:
An example optical system includes freeform mirrors configured to receive light from an object and to reflect the light among the freeform mirrors to produce an optical image of the object having positive distortion. The freeform mirrors include non-rotationally symmetric mirrors. The optical system also includes an along-track scanner having a line of imaging sensors configured to receive the optical image of the object from the freeform mirrors and to produce an image of the object having the positive distortion.
Abstract:
A non-relayed reflective triplet and a double-pass imaging spectrometer including the reflective triplet configured as its objective. In one example the reflective triplet includes a primary mirror that receives and reflects electromagnetic radiation from a viewed scene and defines an optical axis of the optical system, a secondary mirror that receives and reflects the electromagnetic radiation reflected from the primary mirror, and a tertiary mirror that receives the electromagnetic radiation reflected from the secondary mirror and focuses the electromagnetic radiation onto an image plane to form an image of the viewed scene. The primary, secondary, and tertiary mirrors together are configured to form a virtual exit pupil for the optical system, the image plane being located between the tertiary mirror and the virtual exit pupil. The reflective triplet is on-axis in aperture and off-axis in field of view.
Abstract:
A five-mirror all-reflective afocal anastigmat. In one example, a five mirror afocal anastigmat includes five mirrors arranged to sequentially reflect from one another electromagnetic radiation received via a system entrance pupil to produce a collimated output beam of the electromagnetic radiation at a system exit pupil, the five mirrors consisting of three positive-powered mirrors and two negative-powered mirrors, wherein optical powers of the five mirrors are balanced to achieve a flat field condition at the system exit pupil.
Abstract:
Millimeter-wave optical imaging systems and methods. In one example, a mm-wave optical imaging system includes a mm-wave imaging detector located at a focal plane of the optical imaging system, an immersion lens directly coupled to the imaging detector and configured to focus the electromagnetic radiation onto the imaging detector, the immersion lens having a curved first surface and an opposing planar second surface, wherein the focal plane is located on the planar second surface and the imaging detector is directly coupled to the planar second surface, a positive power primary mirror configured to reflect the electromagnetic radiation towards the immersion lens, and a Schmidt aspheric corrector configured to receive and direct the electromagnetic radiation towards the primary mirror, wherein the system aperture stop is located on the Schmidt aspheric corrector.
Abstract:
An optical sensor system having an extended elevation field of view and in which the optics are configured around an all-reflective four-mirror reimaging anastigmat used for afocal foreoptics and an all-reflective five-mirror reimaging anastigmat used for imaging optics. One example of an optical sensor system includes afocal foreoptics configured to receive and collimate electromagnetic radiation, the afocal foreoptics including an all-reflective, reimaging four-mirror anastigmat, an imaging detector, focal imaging optics positioned between the afocal foreoptics and the imaging detector and configured to receive the collimated beam of electromagnetic radiation from the afocal foreoptics and to focus the beam of electromagnetic radiation onto the imaging detector, the focal imaging optics including a reimaging five-mirror anastigmat, wherein a field of view of the system is determined at least in part by a combination of the afocal foreoptics and the focal imaging optics and covers at least 5 degrees in elevation.
Abstract:
An optical sensor assembly in which a four axis gimbal and dual coelostat mirror configuration provide pointing of the sensor line of sight in azimuth and elevation, stabilized for platform pitch. One example of a sensor system includes a first optical sub-system including a first plurality of optical elements, and a second optical sub-system configured to rotate about a first axis relative to the first optical sub-system. The second optical sub-system includes afocal foreoptics configured to direct a collimated beam of electromagnetic radiation to the first optical sub-system, a first coelostat minor configured to rotate about a second axis substantially perpendicular to the first axis, and a second coelostat mirror configured to rotate about a third axis substantially perpendicular to both the first axis and the second axis, and to receive electromagnetic radiation reflected by the first coelostat minor and to direct the electromagnetic radiation to the afocal foreoptics.