In this paper, biologically-inspired optical imaging systems, including fish eye, bug eye, lobster eye, and RGB color
vision, are discussed as new lensing systems for military and homeland security applications. This new area of interest
includes UV, VIS, IR, and X-ray part of electromagnetic spectrum. In particular, recent progress at Physical Optics
Corporation will be discussed, including such applications as hyperspectral/multi-spectral imagery, video surveillance,
and X-ray inspection.
The angular distribution of the inelastic scattering of photons at low energies (≤80 KeV) has been measured in organic material, soil, rocks, wood, steel sheet, and water. The measurements have been performed under air inside an X-ray shield cabinet using X-rays tube as a photon source and a thermoelectrically cooled CdTe detector. Measurements have been taken for both single and combined materials. The contributions of inelastic scattering of photons for the lower Z material in a given configuration have been extracted. The measured signal is primarily Compton scattering. The measured inelastic scattering contributions were compared with the calculated inelastic scattering cross sections according to the Klein-Nishina theory, updated to include a practical energy distribution of an X-ray tube beam. Relatively good agreement was found for all targets under investigation. The slight discrepancy is attributed to photoelectric effect and sample configuration. Present results may act as a guide for optimization of X-ray imaging sensors and in particular of those based on lobster eye X-ray optics suitable for cargo inspection, improvised explosives detection, non-destructive evaluation, and medical imaging.
This paper presents feasibility studies of a multispectral moving target detection (MTD) system designed to detect and track low-signature moving targets. The system performs multispectral detection based on linear and nonlinear optimal discriminating features (ODF) for low-signature target detection and correlation tracking of slowly moving targets in clutter. Multispectral detection was tested against multispectral data from an acousto-optic tunable filter in the visible and near infrared. Optical Joint Transform Correlator for target tracking was designed and manufactured. The feasibility of correlation target tracking was demonstrated with actual Army MICOM FLIR long wavelength infrared (LWIR: 8 to 12 μm) images of moving vehicles and tanks in clutter.
This paper presents feasibility studies of a multispectral moving target detection (MTD) system designed to detect and track low-signature moving targets. The system performs multispectral detection based on linear and nonlinear maximum discrimination and representation features (MRDF) for low-signature target detection and correlation tracking of slowly moving targets in clutter. Multispectral detection was tested against multispectral data from an acousto-optic tunable filter in the visible and near IR. The feasibility of correlation target tracking was demonstrated with actual Army MICOM FLIR long wavelength IR images of moving vehicles and tanks in clutter.
KEYWORDS: Robotics, Video compression, Video, Haptic technology, Surgery, Telecommunications, Wavelets, Commercial off the shelf technology, Medical imaging, Chromium
In this paper a novel teleparamedic robot concept, based on high practicality and economy has been presented. This new UGV (Unmanned Ground Vehicle) has haptic feedback-based driving and teleparamedic robotic operation, based on true 3-D visualization. The robotic operations include: soldier evacuation and two basic FAM (First Aid Measure) modes.
KEYWORDS: LIDAR, 3D displays, 3D image processing, Visualization, Optical sensors, Environmental sensing, 3D visualizations, Profilometers, Sensors, 3D vision
In this paper, LIDAR imaging sensors, 3D synthetic and natural object-centric environment, and temporal ATR are discussed in the context of Modeling and Simulation and Hardware-in-the-loop testing.
KEYWORDS: Video, Video surveillance, Chromium, Telecommunications, Data communications, Video compression, Surveillance, Wireless communications, Video processing, Packaging
The future C41 systems, operating at the digital battlefield should be able to transmit high-quality digital live video and imagery through low-bandwidth communication channels. In this paper, we propose low-bandwidth (64 kbps) wireless transmission of TV-class VGA/NTSC-video (221 Mbps-original bandwidth), integrated with still imagery. For the first time, low-compressed MPEG I-frames will be used as high quality still images, representing every I-frame video stream. As a result, we will be able to transmit high quality both temporal and spatial events, while still preserving low-bandwidth transmission, a fundamental goal for video/imagery surveillance at the digital battlefield.
This paper presents experimental results of hyperspectral image compression by means of soft computing. Compressions and transmission of hyperspectral data requires intensive computation and sophisticated processing that have been incompatible with on-board real-time operation. Soft computing with intelligent processing optimizes the compression parameters of MPEG 1, tuning them to the specific video content to deliver the highest hyperspectral video compression quality. This soft computing approach is compared with compression based on wavelet transform.
We suggest a new concept of the transient functionally graded materials for power conversion from the infrared and/or optical radiation. By illuminating homogeneous material with space-time modulated radiation, an array of thermoelectric and photoelectric devices (thermoelements and photoelements) can be created. These arrays can generate electric current. The proposed TFGM concept is the extension of a known FGM method. It potentially has an advantage of higher conversion efficiency due to transient nature of power conversion. The theory of TFGM for thermoelectric and pyroelectric materials was developed. It describes the generation of both AC and DC electric currents, and the application of the developed theory for a self-powered vibration sensing is discussed also.
Rapid control of the parameters of infrared radiation, such as amplitude, phase and the direction of propagation, is important in a number of military and commercial applications. Some examples are radar and lidar beam modulation and steering, optical communications and information processing. The suitability of canted antiferromagnet hematite ((alpha) -Fe2O3) for such applications is discussed. Experimental results of optical transmission in the 1 - 5 micrometers spectral interval, magneto- induced birefringence, acousto-magneto-optic diffraction, and the magnetic field dependencies of diffraction angle and efficiency (at a wavelength of 1.55 micrometers ) are presented in this paper. The combination of magneto-optic properties, which potentially introduce large induced birefringence, and acoustics (periodic modulation of birefringence along the cross-section of the optical beam), demonstrates enhanced efficiency of acousto-optic diffraction. Furthermore, an additional degree of freedom, which is the magnetic field tuning of acoustic velocities, is introduced. Directions for future development are also discussed.
Physical Optics Corporation has developed an automatic polarization sensitive multispectral imaging system for real-time object-to-background contrast enhancement. This system is built around an acousto-optic tunable filter and liquid crystal achromatic rotator of light polarization.
Vibration sensors provide very important information for an unattended ground sensor network. For this specific application, a vibration sensor must be extremely robust and must have very high sensitivity and very low power consumption. The authors experimentally demonstrated two schemes of fiber optic interferometric sensors capable of sensing vibrations with amplitudes of a few tens of picometers in the frequency range below 1 kHz. The proposed schemes consist of commercially available components and make possible fabrication of a ruggedized, highly sensitive sensor with low power consumption.
This presentation describes the major performance characteristics of the developed camera and demonstrates some results of target contrast enhancement in laboratory and field experiments.
By utilizing the unique AOTF feature of varying its spectral transmission according to the spectrum of the driving RF signal, Physical Optics Corporation developed an automatic hyperspectral system for real-time target contrast enhancement and target tracking.
In this paper, we propose an integration of two techniques: catastrophe-based image compression/coding, and hyperspectral video, based on acousto-optic technology. As a result, we obtain a joint tool for sensing and transmission of hyperspectral data, with minimized bandwidth and latency.
The recently developed technology of spectrally-adaptive light filtering has been applied to create a spectrally-matched filter directly in the optical channel, to select a target with a known spectral signature over an ambient background. The approach to ATR described eliminates intensive computer post-processing of multispectral images, making real-time target detection with enhanced signal-to-clutter ratio possible.
A technology of spectrally adaptive light filtering has been demonstrated, which allows changing the transmission curve of an optical filter in an octave-wide spectral interval with the kilohertz rate under full computer control. This technology utilizes the unique capability of acousto-optic tunable filters to transmit light in several spectral intervals simultaneously, driven by radio signals with complex spectra. A computer algorithm to synthesize the driving signal for an arbitrary given spectral transmission curve was developed. This algorithm has been used for various applications of this developed technology in the visible, SWIR, and MWIR spectral intervals.
A new approach to imaging colorimeter design has been demonstrated. This approach is based on the concept of spectrally adaptive filtering of images, which permits adjustment of the overall response of the system for measuring color coordinates to fit one of three color matching functions and to change its spectral response rapidly. The experiments conducted demonstrated high spatial resolution -- 512 by 512 pixels or more (for nonpixelated objects), capability of performing color coordinate measurements of an entire image in 1/30 second, and high measurement accuracy.
A light-induced grating aperture (LIGA) is a semiconductor plate containing a periodic structure formed of nonequilibrium light-induced electron-hole plasma. The presence of excess charge carriers in a semiconductor medium locally changes the dielectric constant of the material. Such a light-induced periodic structure can serve as a diffraction grating for millimeter waves (MMW), and generates diffracted beams propagating in directions distinct from that of the incident beam. The angle between the incident and diffracted beams depends on the period (Lambda) of the light-induced grating, a parameter that can be controlled using a liquid crystal display (LCD). The effect is strong enough not only for academic study but for practical application as well. The authors fabricated a new scanning MMW antenna in which MMW is diffracted by a LIGA.
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