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At least 1,009 records · Page 56

Angiocardiography - Past and present

Angiocardiography is defined as an X-ray procedure which uses an intravascularly injected contrast material for visualization of the internal anatomy of the heart and great vessels. Past and present efforts in angiocardiography technology and methodology are reviewed, with special emphasis on qualitative and quantitative measurements of heart and vessel geometry. One of the more recent applications of angiographic image analysis has been for pattern recognition of margin motions over a cardiac cycle, termed contourography. Angiocardiography will continue to serve, as it has served in the past, as the principal standard of reference for calibration and/or comparison of newer methods for determining volume or dimensional change, depending on further technologic advances in X-ray equipment and means for displaying computer-processed information.

Sandler, H.↗

Monitoring water quality by remote sensing

The author has identified the following significant results. A limited study was conducted to determine the applicability of remote sensing for evaluating water quality conditions in the San Francisco Bay and delta. Considerable supporting data were available for the study area from other than overflight sources, but short-term temporal and spatial variability precluded their use. The study results were not sufficient to shed much light on the subject, but it did appear that, with the present state of the art in image analysis and the large amount of ground truth needed, remote sensing has only limited application in monitoring water quality.

Brown, R. L.↗

An image-processing system applied to earth-resource imagery

The Harwell Image Processing System (HIPS) has been adapted for processing earth-resource imagery in either film or tape format. Data from film are obtained using a computer-controlled flying-spot scanner. Local rapid interactive processing is based on a PDP 11/20 minicomputer which has suitable display facilities for immediate visual appraisal of results and also a fast data link to an IBM 370/168 computer complex. An extensive subroutine library is being assembled for data preprocessing and feature extraction. This chapter includes a discussion of the basic principles of image analysis, a description of the HIPS system, and finally, for illustrative purposes, a description of several simple software routines.

Carter, P.↗

Cloud type separation by spectral differencing of image pairs

A technique is presented for discriminating different cloud types through an image subtraction of visible and infrared SMS/GOES picture pairs. The technique emphasizes how one could separate snow from clouds and identify cirrus by the subtraction method. Quantitative threshold values are shown which can be used in an objective manner to make this separation. Use is made of an all-digital image display device allowing such mathematical operations to be performed on satellite data. Techniques such as this can be made operational through the interfacing of the image analysis system with a direct-readout SMS/GOES ground station and distribution network.

Reynolds, D. W.↗

Analyzing earth's surface data

Manual discusses simple inexpensive image analysis technique used to interpret photographs and scanner of data of Earth's surface. Manual is designed for those who have no need for sophisticated computer-automated analysis procedures.

Barr, D. J.↗

Evaluation of reforested areas using LANDSAT imagery

The author has identified the following significant results. Visual and automatic interpretation of LANDSAT imagery was used to classify the general Pinus and Eucalyptus according to their age and species. A methodology was derived, based on training areas, to define the legend and spectral characteristics of the analyzed classes. Imager analysis of the training areas show that Pinus taeda is separable from the other Pinus species based on JM distance measurement. No difference of JM measurements was observed among Eucalyptus species. Two classes of Eucalyptus were separated according to their ages: those under and those over two years of age. Channel 6 and 7 were suitable for the discrimination of the reforested classes. Channel 5 was efficient to separated reforested areas from nonforested targets in the region. The automatic analysis shows the highest classification precision was obtained for Eucalyptus over two years of age (95.12 percent).

Dejesusparada, N.↗

Program for plasma-sprayed self-lubricating coatings

A method for preparing composite powders of the three coating components was developed and a procedure that can be used in applying uniform coatings of the composite powders was demonstrated. Composite powders were prepared by adjusting particle sizes of the components and employing a small amount of monoaluminum phosphate as an inorganic binder. Quantitative microscopy (image analysis) was found to be a convenient method of characterizing the composition of the multiphase plasma-sprayed coatings. Area percentages and distribution of the components were readily obtained by this method. The adhesive strength of the coating to a nickel-chromium alloy substrate was increased by about 40 percent by a heat treatment of 20 hours at 650 C.

Walther, G. C.↗

Eulusmap - An international land resources map utilizing satellite imagery

The paper describes the European land use map ('Eulusmap') sponsored by the World Land Use Survey Commission and printed in May 1978. The map was compiled on the basis of theme extraction techniques applied to Landsat-1 imagery. Various aspects of Landsat-image analysis are discussed here, and detailed consideration is given to the land-use classification system developed by the World Land Use Survey Commission.

Paludan, T.↗

LACIE analyst interpretation keys

Two interpretation aids, 'The Image Analysis Guide for Wheat/Small Grains Inventories' and 'The United States and Canadian Great Plains Regional Keys', were developed during LACIE phase 2 and implemented during phase 3 in order to provide analysts with a better understanding of the expected ranges in color variation of signatures for individual biostages and of the temporal sequences of LANDSAT signatures. The keys were tested using operational LACIE data, and the results demonstrate that their use provides improved labeling accuracy in all analyst experience groupings, in all geographic areas within the U.S. Great Plains, and during all periods of crop development.

Baron, J. G.↗

Upgrading the free flying rendezvous and docking simulator and the orbital servicer system

Recommendations are made for upgrading two teleoperator/robotics test and simulation systems based upon a review of latest technology advances in the involved disciplines. A second generation Free Flying Mobility Unit is recommended which adds a sixth degree of freedom and incorporates other improvements which greatly expand the center's capability to perform evaluation tests and demonstrations of advanced systems concepts for rendezvous and docking in support of the Teleoperator Maneuvering System (TMS) Program. The Orbital Servicer System provides the capability for testing and demonstrating concepts for on orbit servicing of compatibly designed satellites/payloads. The TMS is to be the transporting vehicle for the servicer. The manipulator arm of the Orbital service System is presently computer controlled in the trajectory portion of the module transfer operation. The ultimate objective is to fully automte its operation requiring additional capabilities in sensors, artificial intelligence, image analysis, communications, computer programming, pattern recognition, kinematics, and manipulator design. It is recommended that the Electronics and Control Laboratory move to acquire the basic competencies in robotics necessary to achieve full automation.

Eastman, R. M.↗

Appendix C: A comparative study of small scale remotely sensed data for monitoring clearcutting in hardwood forests

Manual photointerpretation techniques were used to analyze images acquired by high altitude aircraft, the Skylab multispectral and Earth terrain camera (ETC), the LANDSAT multispectral scanner, and the LANDSAT-3 return beam vidicon camera. A color-additive viewer, and digital image analysis were also used on the LANDSAT MSS imagery. The value of each type of remotely sensed data was judged by the ease and accuracy of clearcut identification, and by the amount of detail discernible, especially regarding revegetation. Results of a site study in the Allegheny National Forest, Pennsylvania indicate that high altitude aerial photography, especially color infrared photography acquired during the growing season, is well suited for identifying clearcuts and assessing revegetation. Although photographs acquired with Skylab's ETC also yielded good results, only incomplete inventories of clearcuts could be made using LANDSAT imagery. Results for the Adirondack region of New York State were similar for the aircraft and satellite photography, but even less satisfactory for the LANDSAT imagery.

Hafker, W. R.↗

NASA: Biomedical applications team

The status of projects involving the adaptation of NASA technologies for medical purposes is reviewed. Devices for the measurement of joint deformation of arthritic hands, the development of an artificial pancreas, provision of an auditory signal to avert epileptic seizures, are described along with the control of medication levels, a compressed air tank to supply power for field dentistry, and an electroencephalogram monitor. The use of the Lixiscope as a portable fluoroscope, thermal laminates for hand and foot warmers for patients with Raynaud's syndrome, and the use of absorptive coatings for instruments for controlling medication levels are described. The applicability of occupation health and safety practices to industry, computerized patient scheduling, impregnation of the common facial tissue with an agent for killing respiratory viruses, commercial applications of anthropometric data, and multispectral image analysis of the skin as a diagnostic tool are reviewed.

Source record↗

Stereographic observations from geosynchronous satellites - An important new tool for the atmospheric sciences

Observations of cloud geometry using scan-synchronized stereo geostationary satellites having images with horizontal spatial resolution of approximately 0.5 km, and temporal resolution of up to 3 min are presented. The stereo does not require a cloud with known emissivity to be in equilibrium with an atmosphere with a known vertical temperature profile. It is shown that absolute accuracies of about 0.5 km are possible. Qualitative and quantitative representations of atmospheric dynamics were shown by remapping, display, and stereo image analysis on an interactive computer/imaging system. Applications of stereo observations include: (1) cloud top height contours of severe thunderstorms and hurricanes, (2) cloud top and base height estimates for cloud-wind height assignment, (3) cloud growth measurements for severe thunderstorm over-shooting towers, (4) atmospheric temperature from stereo heights and infrared cloud top temperatures, and (5) cloud emissivity estimation. Recommendations are given for future improvements in stereo observations, including a third GOES satellite, operational scan synchronization of all GOES satellites and better resolution sensors.

Hasler, A. F.↗

Effect of aluminum phosphate additions on composition of three-component plasma-sprayed solid lubricant

Image analysis (IA) and electron microprobe X-ray analysis (EMXA) were used to characterize a plasma-sprayed, self-lubricating coating, NASA LUBE PS106, specified by weight percent as 35NiCr-35Ag-30CaF2. To minimize segregation of the powder mixture during the plasma-spraying procedure, monoaluminum phosphate was added to form agglomerate particles. Three concentrations of AlPO4 were added to the mixtures: 1.25, 2.5, and 6.25 percent by weight. Analysis showed that 1.25 wt% AlPO4 yielded a CaF2 deficiency, 2.5 wt% kept the coating closest to specification, and 6.25 wt% yielded excess CaF2 as well as more impurities and voids and a deficiency in silver. Photomicrographs and X-ray maps are presented. The methods of IA and EMXA complement each other, and the reasonable agreement in the results increases the confidence in determining the coating composition.

Jacobson, T. P.↗

The Pacific Northwest story

The establishment of image analysis facilities for the operational utilization of LANDSAT data in Idaho, Oregon, and Washington is discussed. The hardware and software resources are described for each facility along with the range of services.

Johnson, K. A.↗

Estimating the quality of pasturage in the municipality of Paragominas (PA) by means of automatic analysis of LANDSAT data

The use of LANDSAT data to evaluate pasture quality in the Amazon region is demonstrated. Pasture degradation in deforested areas of a traditional tropical forest cattle-raising region was estimated. Automatic analysis using interactive multispectral analysis (IMAGE-100) shows that 24% of the deforested areas were occupied by natural vegetation regrowth, 24% by exposed soil, 15% by degraded pastures, and 46% was suitable grazing land.

Dejesusparada, N.↗

Study of atmospheric diffusion using LANDSAT

The parameters of diffusion patterns of atmospheric pollutants under different conditions were investigated for use in the Gaussian model for calculation of pollution concentration. Value for the divergence pattern of concentration distribution along the Y axis were determined using LANDSAT images. Multispectral scanner images of a point source plume having known characteristics, wind and temperature data, and cloud cover and solar elevation data provided by LANDSAT, were analyzed using the 1-100 system for image analysis. These measured values are compared with pollution transport as predicted by the Pasquill-Gifford, Juelich, and Hoegstroem atmospheric models.

Torsani, J. A.↗

Wideband comet camera lens design

A quarter-meter diameter, modified Ritchey-Chretien camera is described for spacecraft-based observation of Halley's Comet. The system will operate over an unusually broad spectral region, from 0.1216 micron (the hydrogen Lyman-alpha line) to 1.1 microns using reflective primary and secondary mirror optics and a thin UV-grade lithium fluoride refractive element as a field corrector near the image plane. The f/12, 3000 mm focal length camera has a 0.4 deg full field of view for operation with a 15 x 15 mm charge-coupled device detector array. The UV-enhanced silicon CCD detector is a 1000 x 1000 array of 15 micron pixels which establishes the system resolution requirement. The optical design and performance are discussed, with an emphasis on the image analysis with respect to pixel resolution elements used for viewing extended objects such as comets.

Huber, E. D.↗