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High Dynamic Range Digital Imaging of Spacecraft
The ability to capture engineering imagery with a wide degree of dynamic range during rocket launches is critical for post launch processing and analysis [USC03, NNC86]. Rocket launches often present an extreme range of lightness, particularly during night launches. Night launches present a two-fold problem: capturing detail of the vehicle and scene that is masked by darkness, while also capturing detail in the engine plume.
Remote sensor digital image data analysis using the General Electric Image 100 analysis system (a study of analysis speed, cost, and performance)
The author has identified the following significant results. It was found that the high speed man machine interaction capability is a distinct advantage of the image 100; however, the small size of the digital computer in the system is a definite limitation. The system can be highly useful in an analysis mode in which it complements a large general purpose computer. The image 100 was found to be extremely valuable in the analysis of aircraft MSS data where the spatial resolution begins to approach photographic quality and the analyst can exercise interpretation judgements and readily interact with the machine.
Propagation of Noise Uncertainty Through Virtual Strain Gauge Formulations for 2D Digital Image Correlation
The effect of displacement uncertainty is examined on 2-dimensional strain, calculated using linear surfaces fitted to the displacement field. A classical engineering error propagation method is used to calculate uncertainty in Green-Lagrangian strain calculations. The derived uncertainty is compared to a Monte Carlo simulation and discrepancies under 2% are seen between these two methods. The effect of virtual strain gauge size, displacement uncertainty, and boundaries on the region of interest on the strain uncertainty are considered. Here, an exponential decay relationship is observed between strain uncertainty and virtual strain gauge size, while a linear relationship is seen between strain and displacement uncertainty. For boundaries in the region of interest, strain uncertainty is affected by the reduced number of points available to perform the regression.
Interactive digital image manipulation system
The system is designed for manipulation, analysis, interpretation, and processing of a wide variety of image data. LANDSAT (ERTS) and other data in digital form can be input directly into the system. Photographic prints and transparencies are first converted to digital form with an on-line high-resolution microdensitometer. The system is implemented on a Hewlett-Packard 3000 computer with 128 K bytes of core memory and a 47.5 megabyte disk. It includes a true color display monitor, with processing memories, graphics overlays, and a movable cursor. Image data formats are flexible so that there is no restriction to a given set of remote sensors. Conversion between data types is available to provide a basis for comparison of the various data. Multispectral data is fully supported, and there is no restriction on the number of dimensions. In this way multispectral data collected at more than one point in time may simply be treated as a data collected with twice (three times, etc.) the number of sensors. There are various libraries of functions available to the user: processing functions, display functions, system functions, and earth resources applications functions.
Fractal mapping of digitized images - Application to the topography of Arizona and comparisons with synthetic images
The concept of fractal mapping is introduced and applied to digitized topography of Arizona. It is shown that the fractal statistics satisfy the topography of the state to a good approximation. The fractal dimensions and roughness amplitudes from subregions are used to construct maps of these quantities. It is found that the fractal dimension of actual two-dimensional topography is not affected by the adding unity to the fractal dimension of one-dimensional topographic tracks. In addition, consideration is given to the production of fractal maps from synthetically derived topography.
Digital image processing for the earth resources technology satellite data.
This paper discusses the problems of digital processing of the large volumes of multispectral image data that are expected to be received from the ERTS program. Correction of geometric and radiometric distortions are discussed and a byte oriented implementation is proposed. CPU timing estimates are given for a System/360 Model 67, and show that a processing throughput of 1000 image sets per week is feasible.
A brief review of digital image processing
The review is presented with particular reference to Skylab S-192 and Landsat MSS imagery. Attention is given to rectification (calibration) processing with emphasis on geometric correction of image distortions. Image enhancement techniques (e.g., the use of high pass digital filters to eliminate gross shading to allow emphasis of the fine detail) are described along with data analysis and system considerations (software philosophy).
Information extraction from digital images of the earth and the planets
An overview is presented of recent developments at the JPL Image Processing Laboratory which emphasize the utilization of a digital computer to automate the process of information extraction from digital imagery. Consideration is given to: (1) the analysis of Viking Orbiter stereo imagery to determine elevation profiles of the Mars surface, (2) the use of Viking Lander stereo imagery to determine nonhazardous surface sample acquisition strategies, (3) the correlation of Landsat imagery with geographically referenced cultural data to determine land use trends, and (4) the generation of mosaics using digital computer techniques.
The spatial structure of terrain - A process signal in satellite digital images
Pattern recognition procedures applied to Landsat imagery carry an implicit assumption that the digital data are independently distributed. That assumption is incorrect over virtually any terrain. Deviations from independence occur because slopes follow a systematic pattern of variation arising from the slope-forming processes. That pattern can be identified using the stochastic process methodology of Box and Jenkins.Angles of adjacent slopes are autocorrelated and the bidirectional reflectance function transfers these systematic slope changes to the sensor. Imagery becomes autocorrelated through this transfer. Autocorrelation in the imagery can be removed through direct calculation from a digital elevation model or by use of stochastic process methodology. The latter has the advantage that the residuals are white noise; and it is applicable in any area, even where a D.E.M. is unavailable. The stochastic process signal can be used to study terrain processes.
Digital image analysis of Landsat data
The paper defines some basic processing functions than can be performed digitally, discusses a variety of computer peripherals including hard copy output devices and television terminals, compares the characteristics of stand-alone image analysis systems, and briefly describes the important features of image processing and geographic information systems software. Several examples are discussed to demonstrate the efficient use of computers through implementation of hard copy image recorders and television display terminals. The commercially available stand-alone image analysis systems include a computer, appropriate peripherals, and sufficient software to perform analysis without other computational support.
Applications of digital image processing techniques to problems of data registration and correlation
An overview is presented of the evolution of the computer configuration at JPL's Image Processing Laboratory (IPL). The development of techniques for the geometric transformation of digital imagery is discussed and consideration is given to automated and semiautomated image registration, and the registration of imaging and nonimaging data. The increasing complexity of image processing tasks at IPL is illustrated with examples of various applications from the planetary program and earth resources activities. It is noted that the registration of existing geocoded data bases with Landsat imagery will continue to be important if the Landsat data is to be of genuine use to the user community.
Comparison of manually produced and automated cross country movement maps using digital image processing techniques
The Image-Based Information System (IBIS) was used to automate the cross country movement (CCM) mapping model developed by the Defense Mapping Agency (DMA). Existing terrain factor overlays and a CCM map, produced by DMA for the Fort Lewis, Washington area, were digitized and reformatted into geometrically registered images. Terrain factor data from Slope, Soils, and Vegetation overlays were entered into IBIS, and were then combined utilizing IBIS-programmed equations to implement the DMA CCM model. The resulting IBIS-generated CCM map was then compared with the digitized manually produced map to test similarity. The numbers of pixels comprising each CCM region were compared between the two map images, and percent agreement between each two regional counts was computed. The mean percent agreement equalled 86.21%, with an areally weighted standard deviation of 11.11%. Calculation of Pearson's correlation coefficient yielded +9.997. In some cases, the IBIS-calculated map code differed from the DMA codes: analysis revealed that IBIS had calculated the codes correctly. These highly positive results demonstrate the power and accuracy of IBIS in automating models which synthesize a variety of thematic geographic data.
CMOS digital imager design from a system-on-a-chip perspective
In this paper, we have identified timing and circuit layout considerations that are critical for implementing a digital CMOS camera-on-a-chip.
Automated Coronal Loop Identification Using Digital Image Processing Techniques
The results of a master thesis project on a study of computer algorithms for automatic identification of optical-thin, 3-dimensional solar coronal loop centers from extreme ultraviolet and X-ray 2-dimensional images will be presented. These center splines are proxies of associated magnetic field lines. The project is pattern recognition problems in which there are no unique shapes or edges and in which photon and detector noise heavily influence the images. The study explores extraction techniques using: (1) linear feature recognition of local patterns (related to the inertia-tensor concept), (2) parametric space via the Hough transform, and (3) topological adaptive contours (snakes) that constrains curvature and continuity as possible candidates for digital loop detection schemes. We have developed synthesized images for the coronal loops to test the various loop identification algorithms. Since the topology of these solar features is dominated by the magnetic field structure, a first-order magnetic field approximation using multiple dipoles provides a priori information in the identification process. Results from both synthesized and solar images will be presented.
Data reduction of digitized images processed from calibrated photographic and spectroscopic films obtained from terrestial, rocket and space shuttle telescopic instruments
The Microvax 2 computer, the basic software in VMS, and the Mitsubishi High Speed Disk were received and installed. The digital scanning tunneling microscope is fully installed and operational. A new technique was developed for pseudocolor analysis of the line plot images of a scanning tunneling microscope. Computer studies and mathematical modeling of the empirical data associated with many of the film calibration studies were presented. A gas can follow-up experiment which will be launched in September, on the Space Shuttle STS-50, was prepared and loaded. Papers were presented on the structure of the human hair strand using scanning electron microscopy and x ray analysis and updated research on the annual rings produced by the surf clam of the ocean estuaries of Maryland. Scanning electron microscopic work was conducted by the research team for the study of the Mossbauer and Magnetic Susceptibility Studies on NmNi(4.25)Fe(.85) and its Hydride.
Application of digital image analysis techniques to antimisting fuel spray characterization
Pulsed ruby laser sheet illumination of the spray is used for the initial recording of data on very-high-resolution photographic film. The digitization of mosaic elements is effected with a vidicon and video digitizer whose output is stored in computer RAM memory for processing. Highly nonspherical elements and a broad range of drop diameters (8-2000 microns) resulting from the unusual rheological properties of the fuel-additive system are accommodated by the device configuration and algorithms. It is found that the generation of two-dimensional images by means of scattered light also eliminates errors resulting from variations in the index of refraction and from the submicron scattering sites that are often present within the modified fuel. No a priori information on the drop size distribution or on the system response to various drop sizes is required.
Digital image processing for the rectification of television camera distortions.
All television systems introduce distortions into the imagery they record which influence the results of quantitative photometric and geometric measurements. Digital computer techniques provide a powerful approach to the calibration and rectification of these systematic effects. Nonlinear as well as linear problems can be attacked with flexibility and precision. Methods which have been developed and applied for the removal of structured system noises and the correction of photometric, geometric, and resolution distortions in vidicon systems are briefly described. Examples are given of results derived primarily from the Mariner Mars 1969 television experiment.