A motion detection algorithm, based on biological and computational models, for focal plane implementation has been developed. This Temporal Domain Optical Flow Measurement (TDOFM) algorithm uses computational components which have direct and compact electronic counterparts. It uses a binary image of zero-crossings, 2 level analog signals, the signs of spatiotemporal derivatives, 1-b multiplica...

A need for active adjustment of a focal plane array (FPA) exists for space based telescopes at Sandia National Laboratories. Legacy systems relied upon manual alignment of the FPA to the optics train. The alignment was done by checking the image then adjusting the position of the FPA with shims, repeated until the desired alignment and focus were achieved. This approach has several drawbacks, i...

The paper presents progress in optical detector technologies during the past 25 years. Classification of two types of detectors (photon detectors and thermal detectors) is done on the basis of their principle of operation. The overview of optical material systems and detectors is presented. Also recent progress in different technologies is described. Discussion is focused mainly on current and ...

The polarimetric vector is a more general descriptor of light than intensity information alone, and it contains physical information about the imaged objects in a scene that traditional intensity based sensors ignore. Polarimeters – devices that measure polarization – are used to extract physical features from an image such as specularities, occluding contours, and material properties. Scientis...

Superpositions of stellar tracings are present in every slitless spectrograph. The probability for such overlaps in the GAIA RVS spectrograph focal plane is estimated using photometric observations of 66 stellar fields, mostly close to the Galactic plane. It is shown that overlaps of bright stars (V < 17) are common near the Galactic plane, and no spectrum is free from superpositions of faint s...

We present two complementary algorithms suitable for using focal-plane measurements to control a wavefront corrector with an extremely high-spatial resolution. The algorithms use linear approximations to iteratively minimize the aberrations seen by the focal-plane camera. The first algorithm, Fast & Furious (FF), uses a weak-aberration assumption and pupil symmetries to achieve fast wavefront r...

Distance measurement in real world has always been one of the challenging tasks to be performed in the field of computer vision. Photographic images are twodimensional depiction of three-dimensional real space. On methodical observation of the same, one can identify some third dimensional properties (like depth information). In this paper we have proposed a method, which employs perspective pro...

Earth’s atmospheric turbulence induces aberrations in the wavefront of the optical signal from a distant spacecraft. These aberrations cause diffusion and spreading of the signal energy in the receiver’s focal plane, potentially resulting in an increase in bit-error rate (BER) by several orders of magnitude when significant background radiation is present, such as during daytime operation. The ...

We compare phase diversity and curvature wavefront sensing. Besides having completely different reconstruction algorithms, the two methods measure data in different domains: phase diversity very near to the focal plane, and curvature wavefront sensing far from the focal plane in quasi-pupil planes, which enable real-time computation of the wavefront using analog techniques. By using information...