<title>Hyperspectral observations of space objects</title>

Abstract

The Phillips Laboratory (PL) and the Florida Institute of Technology have developed several advanced visible (0.4 -0.8 jim) Imaging Fourier Transform Spectrometer (IFTS) brassboards. These instruments simultaneously acquire one spatial and one spectral dimension of the hyperspectral image cube, and may be scanned across a scene or configured with a scan mirror to pick up the second spatial dimension. Initial laboratory and field demonsti-ations bave indicated the utility hyperspectral imagery as a diagnostic technique for space object target spectral signature identification-a capability which is not presently available for routine use on any PL ground-based optical system. Our current visible hyperspectral imagers possess a combination of features, including (1) low to moderate spectral resolution for hundreds/thousands of spectral channels, (ii) robust design, with no moving parts, (iii) detector limited free spectral range, (iv) detector-limited spatial and spectral resolution, and (v) field widened operation. The IFTS design is also well suited for observations oftemporally varying scenes, in which simultaneous spatial/spectral signature information is required for a target which may be moving erratically within the field of view, or for other application where low to moderate spectral resolution yields useflul information. The HYSAT (ilyperspectral effite) brassboard has been used to observe sateffites and other space objects.In this paper we present (1) the optical system design and operational overview, (ii) laboratory evaluation spectra, and (iii) a sample ofthe first observational data taken with HYSAT.The hyperspectral sensor systems which are being developed and whose utility is being pioneered by the Phillips Laboratory are applicable to several important SOl (space object identification), military, and èivil applications including (i) spectral signature simulations, satellite model validation, and satellite database observations and (iii) simultaneous spatial/spectral observations ofbooster plumes for strategic and surrogate tactical missile signature identification. The sensor system is also applicable to a wide range of other applications, including astronomy, camouflage discrimination, smoke chemical analysis environmental/agricukural resource sensin& terrain analysis, and ground surveillance. Only SOl applications will be discussed here.

<title>Set-theoretic deconvolution (STD) for multichromatic ground/air/space-based imagery</title>

“…(a) The basic Doppler phenomenon combined with target rigidity enables observer not only to oblain highangular-resolution images, but also to uniquely tag cross-range position of each scattering center attributed to (1) STD does not presume knowledge of the instantaneous PSF and infinite-ensemble statistics models for PSF and its moments, as well as excludes seeing parameter measurement, (2) STD, in application to static astronomical object, permits double statistical averaging, i.e., empirical summing up of the extra-long series of snapshots (or ones extra-separated in time) pertaining to different seeing parameter realizations, ro(t), if a temporal wide-sense-stationarity of the resultant unknown OTF SP takes place, (3) STD unnecessitates the long image sequence registration for each of M monochrome object's signatures and subsequent averaging over many snapshots if object (f.e., booster plume or satellite) is bright enough (At low light level, the price to be paid is that the large series of snapshots is recorded. (a) The basic Doppler phenomenon combined with target rigidity enables observer not only to oblain highangular-resolution images, but also to uniquely tag cross-range position of each scattering center attributed to (1) STD does not presume knowledge of the instantaneous PSF and infinite-ensemble statistics models for PSF and its moments, as well as excludes seeing parameter measurement, (2) STD, in application to static astronomical object, permits double statistical averaging, i.e., empirical summing up of the extra-long series of snapshots (or ones extra-separated in time) pertaining to different seeing parameter realizations, ro(t), if a temporal wide-sense-stationarity of the resultant unknown OTF SP takes place, (3) STD unnecessitates the long image sequence registration for each of M monochrome object's signatures and subsequent averaging over many snapshots if object (f.e., booster plume or satellite) is bright enough (At low light level, the price to be paid is that the large series of snapshots is recorded.…”

Hyperspectral imaging of retinal microvascular anatomy

“…Hyperspectral imaging systems, which are systems capable of detecting unique spectral information for identification purposes, were first pioneered for use in fields such as the earth and planetary sciences [1] . Since then, hyperspectral imaging systems have emerged in fields including ophthalmology [2][3][4] , oncology [5,6] , fluorescence microscopy [7] , bioinformatics [8] , vascular physiology [9,10] , archeology and art conservation [11] , and even forensic science [12,13] .…”