NASA Technical Reports Server (Ntrs) 19750022769: Two-Dimensional Convolute Integers for optical Image dataprocessing and Surface Fitting by NASA Technical Reports Server (Ntrs); published by
NASA Technical Reports Server (Ntrs) 19750022769: Two-Dimensional Convolute Integers for optical Image dataprocessing and Surface Fitting by NASA Technical Reports Server (Ntrs); published by
An opticaldata-processing system is defined as an arrangement, in which a two-dimensional optical ″signal″ prescribed in an object plane is transformed into another ″signal″ available in the image plane. The same...
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An opticaldata-processing system is defined as an arrangement, in which a two-dimensional optical ″signal″ prescribed in an object plane is transformed into another ″signal″ available in the image plane. The same physical arrangement can also be used in the opposite direction of transmission, with the roles of object and image plane interchanged. In this paper, a reciprocity relation between the transmission properties in the two directions is derived from Helmholtz's equation.
The optical computer, originating in numerous research laboratories, operates by means of laser light. Its high processing speed is based mostly on parallel dataprocessing. The fundamentals of the hardware are extens...
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The optical computer, originating in numerous research laboratories, operates by means of laser light. Its high processing speed is based mostly on parallel dataprocessing. The fundamentals of the hardware are extensively investigated, while its technical realization will require still more time.
A near real-time data recorder or modulator which employs electron beam writing on a deformable thermoplastic layer has been developed for processing of synthetic aperture radar (SAR) data. This paper reviews design a...
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A near real-time data recorder or modulator which employs electron beam writing on a deformable thermoplastic layer has been developed for processing of synthetic aperture radar (SAR) data. This paper reviews design and performance features of the modulator. Recording by deformation of the thermoplastic is realized when the writing electron beam, which is intensity modulated in proportion to the input signal to be recorded, deposits a charge pattern on the plastic surface. At elevated temperature of 50 degree to 70 degree C the viscosity of the plastic is reduced so that the electrostatic forces of the deposited charges cause the plastic to deform until an equilibrium is reached with the opposing surface tension forces of the plastic layer. At sufficiently high temperatures the resistance of the thermoplastic is decreased. This allows the charge to be conducted away to a transparent conductive coating that lies between the thin plastic layer and its glass substrate. Plastic layers in the range of 5 to 10 mu m thickness have been used thus far. The materials employed appear to have a potential for high recycle (re-use) life. Several different radar signals are available depending upon the design of the SAR system and each requires its particular recording format and optical processor design. Such signal types include astigmatic Fresnel zone plate and linear gratings. Diagrams and photographs are included.
Significant advancements in integrated photonics have enabled high-speed and energy efficient systems for various applications, from data communications and high-performance computing to medical diagnosis, sensing, an...
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Significant advancements in integrated photonics have enabled high-speed and energy efficient systems for various applications, from data communications and high-performance computing to medical diagnosis, sensing, and ranging. However, data storage in these systems has been dominated by electronic memories that in addition to signal conversion between optical and electrical domains, necessitates conversion between analog to digital domains and electrical data movement between processor and memory that reduce the speed and energy efficiency. To date, scalable optical memory with optical control has remained an open problem. Here, we report an integrated photonic set-reset latch as a fundamental optical static memory unit based on universal optical logic gates. As a proof of concept, experimental implementation of the universal logic gates and realistic simulation of the latch are demonstrated on a programmable silicon photonic platform. optical set, reset, and complementary outputs, scalability to a large number of memory units via the independent latch supply light, and compatibility with wavelength division multiplexing scheme and different photonic platforms enable more efficient and lower latency opticalprocessing systems.
A near real-time data recorder or modulator which employs electron beam writing on a deformable thermoplastic layer has been developed for processing of synthetic aperture radar (SAR) data. This paper reviews design a...
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A near real-time data recorder or modulator which employs electron beam writing on a deformable thermoplastic layer has been developed for processing of synthetic aperture radar (SAR) data. This paper reviews design and performance features of the modulator. Recording by deformation of the thermoplastic is realized when the writing electron beam, which is intensity modulated in proportion to the input signal to be recorded, deposits a charge pattern on the plastic surface. At elevated temperature of 50 degree to 70 degree C the viscosity of the plastic is reduced so that the electrostatic forces of the deposited charges cause the plastic to deform until an equilibrium is reached with the opposing surface tension forces of the plastic layer. At sufficiently high temperatures the resistance of the thermoplastic is decreased. This allows the charge to be conducted away to a transparent conductive coating that lies between the thin plastic layer and its glass substrate. Plastic layers in the range of 5 to 10 mu m thickness have been used thus far. The materials employed appear to have a potential for high recycle (re-use) life. Several different radar signals are available depending upon the design of the SAR system and each requires its particular recording format and optical processor design. Such signal types include astigmatic Fresnel zone plate and linear gratings. Diagrams and photographs are included.
Currently, multi-target survey telescope arrays play an important role in the build-up and maintenance of space object catalog databases, collecting massive observational data without attributing information. However,...
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Currently, multi-target survey telescope arrays play an important role in the build-up and maintenance of space object catalog databases, collecting massive observational data without attributing information. However, the matching process of massive observational data poses significant challenges to traditional prediction methods. To address the issues of low matching success rates and prolonged computation times in traditional methods, this paper proposes a multi-threaded data starting point matching method. First, orbital elements from the Space Surveillance and Tracking (SST) database are extracted for two days before and after the observation moment. A set of orbital elements closest to the observation epoch is filtered to form the primary candidate catalog containing the maximum number of objects. A matching error threshold is set. Second, multi-threaded traversal of the primary candidate catalog is performed to calculate observation residuals with the data starting point using an orbit prediction procedure. Orbital elements meeting the triple matching error threshold are selected to form the secondary candidate catalog, which is used in the entire data arc segment-matching calculation. Finally, the root mean square error (RMSE) of observation residuals for the entire data arc segment is computed point by point. The orbital elements satisfying the matching threshold are identified as matching results based on the principle of optimality. Experimental results demonstrate that with a matching error threshold of 1 degrees, the proposed method achieves an average matching success rate of 97.62% for data arc segments with nearly 10,000 passes per day over 8 consecutive days. In the SST database containing an average of 25,720 targets, this method processes an average of 2164 data arc segments per minute, improving matching efficiency by 115 times compared to traditional prediction methods.
The optical half-adder is one of the important components in the design of optical digital circuits. In this study, an optical half-adder based on two-dimensional photonic crystals with a square lattice has been desig...
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The optical half-adder is one of the important components in the design of optical digital circuits. In this study, an optical half-adder based on two-dimensional photonic crystals with a square lattice has been designed, optimized, and simulated. A feedforward neural network model is used to achieve the optimal state by selecting the defect rod dimension and phase of the input laser to optimize the performance of the optical device. The results show that the proposed structure has an appropriate power difference in both high and low logic states, which results in fewer errors in detecting logical values at the outputs. Another feature of this structure is the use of a minimal number of defect rods and the absence of ring resonators, which leads to a reduction in size and propagation delay time of light in the structure. Moreover, due to its aforementioned features and small size, this structure is suitable for use in integrated optical circuits. (c) 2025 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.
Vectorial rock fabric data, from the scale of photomicrographs to that of aerial photographs, can be analyzed by an opticaldata-processing method already applied to seismic data. Each photograph is reduced to a trans...
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In the face of the increasing need to be able to process two-dimensionally organized data, the present electronic digital processing and coherent optical data processing techniques have proven inadequate. The potentia...
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