AISA hyperspectral imagers have been utilized in airborne applications for various defense related Intelligence, Surveillance and Reconnaissance (ISR) applications. In expanding the utility and capabilities of hyperspectral imagers for defense related applications, the implementation in a ground scanning configuration for check-point and forensic purposes has been achieved. System specifications, design, and operational considerations for a fully automated, near real-time target detection capability are presented. The system utilizes modularized software architecture, combining C++ command, capture, calibration, and messaging functions with drop-in IDL exploitation module for detection algorithm and target set flexibility. Performance capability against known defense related targets of interest have been tested, verified, and are presented utilizing full 400-2450nm spectral range provided by combined AisaEAGLE and AisaHAWK hyperspectral imagers. Initial results are also described for a new extended InGaAs system, covering 585-1630nm to provide a similar capability for integrations which have size, weight, and power restrictions.
A multi-modal (hyperspectral, LiDAR, and multi-spectral) imaging data collection campaign was conducted at
the Rochester Institute of Technology (RIT) in conjunction with SpecTIR, LLC, in the Rochester, New York, area
July 26-29, 2010. The campaign was titled the SpecTIR Hyperspectral Airborne Rochester Experiment (SHARE)
and collected data in support of nine simultaneous unique experiments, several of which leveraged data from
multiple modalities. Airborne imagery was collected over the city of Rochester with hyperspectral, multispectral,
and Light Detection and Ranging (LiDAR) sensors. Sites for data collection included the Genesee River, sections
of downtown Rochester, and the RIT campus. Experiments included sub-pixel target detection, water quality
monitoring, thermal vehicle tracking and wetlands health assessment. An extensive ground truthing effort was
accomplished in addition to the airborne imagery collected. The ultimate goal of this comprehensive data
collection campaign was to provide a community sharable resource that would support additional experiments.
This paper details the experiments conducted and the corresponding data that were collected in conjunction
with this campaign.
Current hyperspectral imagers are either bulky with good performance, or compact with only moderate performance.
This paper presents a new hyperspectral technology which overcomes this drawback, and makes it possible to integrate
extremely compact and high performance push-broom hyperspectral imagers for Unmanned Aerial Vehicles (UAV) and
other demanding applications. Hyperspectral imagers in VIS/NIR, SWIR, MWIR and LWIR spectral ranges have been
implemented. This paper presents the measured performance attributes for a VIS/NIR imager which covers 350 to 1000
nm with spectral resolution of 3 nm. The key innovation is a new imaging spectrograph design which employs both
transmissive and reflective optics in order to achieve high light throughput and large spatial image size in an extremely
compact format. High light throughput is created by numerical aperture of F/2.4 and high diffraction efficiency. Image
distortions are negligible, keystone being <2 um and smile 0.13 nm across the full focal plane image size of 24 mm
(spatially) x 6 m (spectrally). The spectrograph is integrated with an advanced camera which provides 1300 spatial pixels
and image rate of 160 Hz. A higher resolution version with 2000 spatial pixels will produce up to 100 images/s. The
camera achieves, with spectral binning, an outstanding signal-to-noise ratio of 800:1, orders of magnitude higher than
any current compact VIS/NIR imager. The imager weighs only 1.4 kg, including fore optics, imaging spectrograph with
shutter and camera, in a format optimized for installation in small payload compartments and gimbals. In addition to
laboratory characterization, results from a flight test mission are presented.
Two long-wave infrared (LWIR) hyperspectral imagers have been under extensive development. The first one utilizes a
microbolometer focal plane array (FPA) and the second one is based on an Mercury Cadmium Telluride (MCT) FPA.
Both imagers employ a pushbroom imaging spectrograph with a transmission grating and on-axis optics. The main target
has been to develop high performance instruments with good image quality and compact size for various industrial and
remote sensing application requirements. A big challenge in realizing these goals without considerable cooling of the
whole instrument is to control the instrument radiation. The challenge is much bigger in a hyperspectral instrument than
in a broadband camera, because the optical signal from the target is spread spectrally, but the instrument radiation is not
dispersed. Without any suppression, the instrument radiation can overwhelm the radiation from the target even by 1000
The means to handle the instrument radiation in the MCT imager include precise instrument temperature stabilization
(but not cooling), efficient optical background suppression and the use of background-monitoring-on-chip (BMC)
method. This approach has made possible the implementation of a high performance, extremely compact spectral imager
in the 7.7 to 12.4 μm spectral range. The imager performance with 84 spectral bands and 384 spatial pixels has been
experimentally verified and an excellent NESR of 14 mW/(m<sup>2</sup>srμm) at 10 μm wavelength with a 300 K target has been
achieved. This results in SNR of more than 700.
The LWIR imager based on a microbolometer detector array, first time introduced in 2009, has been upgraded. The
sensitivity of the imager has improved drastically by a factor of 3 and SNR by about 15 %. It provides a rugged
hyperspectral camera for chemical imaging applications in reflection mode in laboratory and industry.
Imaging spectrometry (also known as "hyperspectal imagery", HSI) data are well established for detailed mineral
mapping from airborne and satellite systems. Overhead data, however, have substantial additional potential when used
together with ground-based HSI measurements. An HSI scanner system was used to acquire airborne data, outcrop
scans, and to image boxed drill core and rock chips at approximately 6nm nominal spectral resolution in 360 channels
from 0.4 - 2.45 micrometers. Analysis results using standardized hyperspectral methodologies demonstrate rapid
extraction of representative mineral spectra and mapping of mineral distributions and abundances. A case history
highlights the capabilities of these integrated datasets for developing improved understanding of relations between
geology, alteration, and spectral signatures in three dimensions.