摘要 :
The purpose of this investigation was to provide a more advanced radiant heat source capable of heating an area of 1 cm with up to 15 cal/cm –sec of radiant heat flux with a uniformity of + 1 percent. The source and the op¬tical...
展开
The purpose of this investigation was to provide a more advanced radiant heat source capable of heating an area of 1 cm with up to 15 cal/cm –sec of radiant heat flux with a uniformity of + 1 percent. The source and the op¬tical imaging system were to provide a high degree of stability and reproducibility for extended periods. The imaging system is to be used in a study of the effects of intense thermal-radiation on living tissues being carried out at the U.S. Naval Air Development Center in Johnsville, Pennsylvania.
The specified radiant heat flux and uniformity has been achieved by using a resistance heated graphite element, 16 iron wid6 find 38 mm long, as the radiation source in conjunction with a compound thermal imaging system. A heat flux-redistributor installed external to the system provided the desired flux uniformity. The completed system and source are shown in Figures 1, 2 and 3. An operation manual for the source and imaging system is included as an Appendix to this report.
收起
摘要 :
Growing concerns, that aquatic noise produced during naval exercises and offshore seismic surveys may be harmful to marine mammals, have led an increasing number of regulating agencies to request mitigation measures when issuing p...
展开
Growing concerns, that aquatic noise produced during naval exercises and offshore seismic surveys may be harmful to marine mammals, have led an increasing number of regulating agencies to request mitigation measures when issuing permits for such surveys in their nations EEZ. The most common measure is to implement a marine mammal watch , a team of observers that scans the ship s environs for signs of presence of marine mammals to trigger a shutdown of the hydroacoustic source when marine mammals are entering a predefined exclusion zone. Marine mammal observers usually scan the ship s environs for whales using binoculars or the naked eye. Sightings mostly rely on spotting a whale s blow, which might rise to a height of several meters but is visible for a few seconds only. Hence, in combination with the whales prolonged dives, sighting opportunities are rare, which, in addition to the limited field of view and finite attention span of human observers, renders this method personnel- intensive and difficult, even during fair weather and daytime. During darkness it is not feasible. Our long-term goal is to overcome these difficulties and to develop a reliable, automatic whale detection system for the full range of oceanic environmental conditions (wind, sea surface temperature) and species. To this end, we developed a ship-based thermal imaging system for automated marine mammal detection, consisting of an actively stabilized, spinning IR camera and an algorithm that detects whale blows on the basis of their thermal signature. So far, this technology has been tailored to and tested under cold (SST < 10 deg C) water conditions only, as this is where the technology was expected to perform best. To adapt the technology to warmer environments and to test its performance there is the specific goal of this proposal.
收起
摘要 :
A new thermal neutron imaging system has been constructed, based on a 20-cm x 17-cm He-3 position-sensitive detector with spatial resolution better than 1 mm. New compact custom-designed position-decoding electronics are employed,...
展开
A new thermal neutron imaging system has been constructed, based on a 20-cm x 17-cm He-3 position-sensitive detector with spatial resolution better than 1 mm. New compact custom-designed position-decoding electronics are employed, as well as high-precision cadmium masks with Modified Uniformly Redundant Array patterns. Fast Fourier Transform algorithms are incorporated into the deconvolution software to provide rapid conversion of shadowgrams into real images. The system demonstrates the principles for locating sources of thermal neutrons by a stand-off technique, as well as visualizing the shapes of nearby sources. The data acquisition time could potentially be reduced two orders of magnitude by building larger detectors.
收起
摘要 :
High resolution thermal images of operating micro refrigerators are presented. Using the thermo reflectance method and a high dynamic range PIN array camera, thermal images with 50mK thermal resolution and high spatial resolution ...
展开
High resolution thermal images of operating micro refrigerators are presented. Using the thermo reflectance method and a high dynamic range PIN array camera, thermal images with 50mK thermal resolution and high spatial resolution are presented. This general method can be applied to any operating semiconductors, and can be used as a tool for identifying fabrication failures. With further optimization of the experimental setup, we expect to achieve sub- micron spatial resolution thermal images.
收起
摘要 :
Measurement of the Optical Transfer Function (OTF) of discretely sampled thermalimaging systems, e.g. parallel scanned FLIR systems, on which analysis is done in the cross scan direction, and staring focal plane arrays, is increas...
展开
Measurement of the Optical Transfer Function (OTF) of discretely sampled thermalimaging systems, e.g. parallel scanned FLIR systems, on which analysis is done in the cross scan direction, and staring focal plane arrays, is increasingly important as digital image acquisition device technology for the 3-5 and 8-12 micron (infrared) spectral regions is maturing. The traditional measurement methods used for continuous scan systems may not be valid for discretely sampled systems. This paper presents results of measurements of the OTF using a translating slit to obtain the Line Spread Function (LSF) for discretely sampled systems. Multiple frame acquisition is used for removal of temporal and fixed pattern noise. It is the intent of this laboratory effort to develop a measurement technique to be used when collecting OTF data for discretely sampled systems. The new measurement technique is potentially suitable for all systems, and if successful, will permit characterization of vertical system MTF. If this measurement, method is found to be useful, it will be used to generate the OTF data used in the NVEOD FLIR92 model for further development and verification of the model.
收起
摘要 :
In this paper, new image processing tools are presented for conversion thermal and visual images, mainly for application in medicine and biology. A novel method for area and distance evaluation based on statistical differencing is...
展开
In this paper, new image processing tools are presented for conversion thermal and visual images, mainly for application in medicine and biology. A novel method for area and distance evaluation based on statistical differencing is discussed. In order to increase the measurements accuracy, the interpolation and subpixel bitmap processing are chosen.
收起
摘要 :
An analysis of infrared background scenes generated by the Naval PostgraduateSchool Infrared Search and Target Designation (NPS-IRSTD) System, and captured with a DT-2861 frame grabber board, was conducted using a FORTRAN program ...
展开
An analysis of infrared background scenes generated by the Naval PostgraduateSchool Infrared Search and Target Designation (NPS-IRSTD) System, and captured with a DT-2861 frame grabber board, was conducted using a FORTRAN program developed to facilitate image enhancement, clutter suppression and visual target discrimination. The developed FORTRAN program, incorporating the X-arRay subroutine library to provide access to the DT-2861 memory buffers in the 80386 extended memory, provides access to pre-defined spatial frequency filters for image processing. The program was used to process image data obtained concurrently with the NPS-IRSTD and an AGA-780 Thermovision system operating in the same (3-5 micrometers) waveband. Image histograms and qualitative features of the two image types have been compared. Application of image enhancement and edge detection filters to IRSTD scenes with and without background clutter is considered. Visual target enhancement is observed, together with additional generation of image noise.
收起
摘要 :
An outstanding problem of thermal wave imaging has been the blurring of theimages, because of the lateral diffusion of heat in the sample. We demonstrate here, both theoretically and experimentally, that this blurring is not due t...
展开
An outstanding problem of thermal wave imaging has been the blurring of theimages, because of the lateral diffusion of heat in the sample. We demonstrate here, both theoretically and experimentally, that this blurring is not due to any inherent loss of information in the diffusion process, but that it can, in fact, be removed by appropriate processing of the image. The result is a very significant improvement of the resolution of the thermal wave imaging process.
收起
摘要 :
The primary motivation for multi-sensor image fusion is to combine the complementary information derived from different modality sensors. Building on the work reported in two of our earlier papers from IRIS Passive Sensors 1996, w...
展开
The primary motivation for multi-sensor image fusion is to combine the complementary information derived from different modality sensors. Building on the work reported in two of our earlier papers from IRIS Passive Sensors 1996, we show how opponent-color processing and center-surround shunting neural networks can be used to develop a variety of image fusion architectures. By emulating single-opponent color processing cells in the retina, and double- opponent color cells in primary visual cortex, we demonstrate an effective strategy for color image fusion as applied to: low-light visible and thermal IR fusion for color night vision, 6-band multispectral fusion for camouflage detection, EO/IR/SAR multi-modal fusion from separate sensor platforms. We have also developed a realtime visible/IR fusion processor from multiple C80 DSP chips using commercially available boards, and use it in conjunction with the Lincoln Lab low-light CCD and an uncooled IR camera. Limited human factors testing of visible/IR fusion has shown improved human performance using our color fused imagery as compared to alternative fusion strategies or either single image modality alone. We conclude that fusion architectures which match opponent-sensor contrasts to human opponent-color pathways will yield fused image products of high image quality and utility.
收起
摘要 :
Image fusion is the process where several independently recorded images arecombined into a single image. This report describes the fusion of thermal IR and visual imagery. For image fusion an optimality criterion is defined. If th...
展开
Image fusion is the process where several independently recorded images arecombined into a single image. This report describes the fusion of thermal IR and visual imagery. For image fusion an optimality criterion is defined. If the input images are assumed to be dependent the optimal fusion process is image blending. For independent input images pyramidal solutions such as Burt's algorithm are shown to be optimal. Several image sequences are processed with the techniques described in the report. Results presented in the report indicate that, for the images used, image fusion results in images with a higher information content. Hardware requirements for the algorithms presented are given. Real-time implementation on current plug-in DSP boards seems possible. An initial study is performed into Automatic Target Recognition based upon multiple input images. The results look promising.
收起
