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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 451 records · Page 25

Compact Video Microscope Imaging System Implemented in Colloid Studies

Long description Photographs showing fiber-optic light source, microscope and charge-coupled discharge (CCD) camera head connected to camera body, CCD camera body feeding data to image acquisition board in PC, and Cartesian robot controlled via PC board. The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. CMIS can be used in situ with a minimum amount of user intervention. This system can scan, find areas of interest in, focus on, and acquire images automatically. Many multiple-cell experiments require microscopy for in situ observations; this is feasible only with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control. The software also has a user-friendly interface, which can be used independently of the hardware for further post-experiment analysis. CMIS has been successfully developed in the SML Laboratory at the NASA Glenn Research Center and adapted for use for colloid studies and is available for telescience experiments. The main innovations this year are an improved interface, optimized algorithms, and the ability to control conventional full-sized microscopes in addition to compact microscopes. The CMIS software-hardware interface is being integrated into our SML Analysis package, which will be a robust general-purpose image-processing package that can handle over 100 space and industrial applications.

McDowell, Mark↗

A Fast Implementation of the ISOCLUS Algorithm

Unsupervised clustering is a fundamental tool in numerous image processing and remote sensing applications. For example, unsupervised clustering is often used to obtain vegetation maps of an area of interest. This approach is useful when reliable training data are either scarce or expensive, and when relatively little a priori information about the data is available. Unsupervised clustering methods play a significant role in the pursuit of unsupervised classification. One of the most popular and widely used clustering schemes for remote sensing applications is the ISOCLUS algorithm, which is based on the ISODATA method. The algorithm is given a set of n data points (or samples) in d-dimensional space, an integer k indicating the initial number of clusters, and a number of additional parameters. The general goal is to compute a set of cluster centers in d-space. Although there is no specific optimization criterion, the algorithm is similar in spirit to the well known k-means clustering method in which the objective is to minimize the average squared distance of each point to its nearest center, called the average distortion. One significant feature of ISOCLUS over k-means is that clusters may be merged or split, and so the final number of clusters may be different from the number k supplied as part of the input. This algorithm will be described in later in this paper. The ISOCLUS algorithm can run very slowly, particularly on large data sets. Given its wide use in remote sensing, its efficient computation is an important goal. We have developed a fast implementation of the ISOCLUS algorithm. Our improvement is based on a recent acceleration to the k-means algorithm, the filtering algorithm, by Kanungo et al.. They showed that, by storing the data in a kd-tree, it was possible to significantly reduce the running time of k-means. We have adapted this method for the ISOCLUS algorithm. For technical reasons, which are explained later, it is necessary to make a minor modification to the ISOCLUS specification. We provide empirical evidence, on both synthetic and Landsat image data sets, that our algorithm's performance is essentially the same as that of ISOCLUS, but with significantly lower running times. We show that our algorithm runs from 3 to 30 times faster than a straightforward implementation of ISOCLUS. Our adaptation of the filtering algorithm involves the efficient computation of a number of cluster statistics that are needed for ISOCLUS, but not for k-means.

Memarsadeghi, Nargess↗

Inverting a dispersive scene's side-scanned image

Consideration is given to the problem of using a remotely sensed, side-scanned image of a time-variant scene, which changes according to a dispersion relation, to estimate the structure at a given moment. Additive thermal noise is neglected in the models considered in the formal treatment. It is shown that the dispersion relation is normalized by the scanning velocity, as is the group scanning velocity component. An inversion operation is defined for noise-free images generated by SAR. The method is extended to the inversion of noisy imagery, and a formulation is defined for spectral density estimation. Finally, the methods for a radar system are used for the case of sonar.

Harger, R. O.↗

Acquisition of Earth Science Remote Sensing Observations from Commercial Sources: Lessons Learned from the Space Imaging IKONOS Example

In an effort to more full explore the potential of commercial remotely sensed land data sources, the NASA Earth Science Enterprise (ESE) implemented an experimental Scientific Data Purchase (SDP) that solicited bids from the private sector to meet ESE-user data needs. The images from the Space Imaging IKONOS system provided a particularly good match to the current ESE missions such as Terra and Landsat 7 and therefore serve as a focal point in this analysis.

Goward, Samuel N.↗

Switching An Image Processor Between Two Computers

Remote-control parallel switching circuit connects either of two computers (but not both simultaneously) to image processor. Includes two parallel switches actuated mechanically by solenoids. Each solenoid controlled by solid-state relay connected to remote-control line from associated computer. One or other solenoid energized to connect image processor to computer requesting access according to protocol implemented in software.

Bodis, Jim↗

Proceedings of the Airborne Imaging Spectrometer Data Analysis Workshop

The Airborne Imaging Spectrometer (AIS) Data Analysis Workshop was held at the Jet Propulsion Laboratory on April 8 to 10, 1985. It was attended by 92 people who heard reports on 30 investigations currently under way using AIS data that have been collected over the past two years. Written summaries of 27 of the presentations are in these Proceedings. Many of the results presented at the Workshop are preliminary because most investigators have been working with this fundamentally new type of data for only a relatively short time. Nevertheless, several conclusions can be drawn from the Workshop presentations concerning the value of imaging spectrometry to Earth remote sensing. First, work with AIS has shown that direct identification of minerals through high spectral resolution imaging is a reality for a wide range of materials and geological settings. Second, there are strong indications that high spectral resolution remote sensing will enhance the ability to map vegetation species. There are also good indications that imaging spectrometry will be useful for biochemical studies of vegetation. Finally, there are a number of new data analysis techniques under development which should lead to more efficient and complete information extraction from imaging spectrometer data. The results of the Workshop indicate that as experience is gained with this new class of data, and as new analysis methodologies are developed and applied, the value of imaging spectrometry should increase.

Vane, G.↗

High Altitude Hyperspectral Remote Sensing with AVIRIS

None given. From Intro: This paper describes AVIRIS (the Airborne Visible and InfraRed Imaging Spectrometer) as a remote sensing instrument that is supported, calibrated, and maintained by JPL.

AVIRIS detector fiberoptics remote sensing spectro↗

Pioneer Jupiter Orbiter/Probe mission. I - Spacecraft system description

This paper discusses the Pioneer Jupiter Orbiter/Probe mission with emphasis on the orbiter spacecraft system. In this mission, the atmosphere of Jupiter will be investigated for physical and chemical structure by a probe which survives entry and transmits data while descending below the 10-bar level. The spacecraft deflects after probe separation to a nonimpacting approach trajectory, acts as a communications relay for data from the descending probe, and propulsively enters an orbit about Jupiter. As an orbiter, it explores the environment of Jupiter for three years, making in situ measurements of the particles and fields of the Jovian magnetosphere together with remote measurements (including images) of Jupiter and the Galilean satellites. The spacecraft system is logically based on the design of Pioneers 10 and 11 with modifications for these different mission requirements: antenna, receiver, and memory for the probe-spacecraft data link; a retropropulsion system for the high velocity-change requirements of orbit insertion; a data system consistent with the requirements of a line-scan imaging system; and an improved complement of radioisotope-thermoelectric-generator power sources to provide adequate power six years after launch.

Lassen, H. A.↗

Satellite communications for disaster relief operations

The use of communication satellite systems to provide assistance in disaster relief operations on a global basis is presented. Disaster problem phases such as detection, warning, and relief; requirements for the communication capability including remote data collection, imaging and voice broadcast; and the global disaster network are discussed. Utilization of Intelsat and Marisat systems and the size and type of ground terminals required for satellite access is considered, and estimates of communication requirements for a global system and of costs for satellite services to support relief operations are given. NASA disaster related activities including studies of direct-to-home disaster warning and determination of disaster response times are described, and it is concluded that existing international satellite communication systems offer real potential for the establishment of a reliable and flexible network devoted to disaster related communication services.

Sivo, J. N.↗

Observation of the Grand Canyon wall structure with an airborne imaging radar

The paper reports on radar images of the Grand Canyon region obtained with the Jet Propulsion Laboratory L-band (25 cm wavelength) airborne synthetic aperture radar in order to determine the capability of such a system to observe wall stratifications compared with optical sensors. Comparisons are made between these and Landsat images of the same area. Finally, it is noted that the observations do not furnish any new information on the geology of the Grant Canyon, rather, they add to the data base which is required in the interpretation of radar images from unknown remote regions such as the surface of Venus.

Elachi, C.↗

Advanced missions to primitive bodies

Six interplanetary spacecraft, three earth orbital experiments, and one spacecraft orbiting Venus will observe comets Halley and Giacobini-Zinner in 1985-86. At comet Halley, attempts will be made to image the nucleus, remote sensing will be made by spectrometers in wavelength ranges from the IR to the UV, and in-situ observations will be made with neutral, ion and dust mass spectrometers. Plasma measurements will be made at both comets and at comet Halley the upstream solar wind flux will be simultaneously monitored by nearby spacecraft. In the post-Halley era, there are several missions being planned for the continued exploration of the solar system's most primitive bodies - comets and asteroids.

Yeomans, D. K.↗

High spectral resolution remote sensing of the earth

Early results of a major advance in remote sensing called imaging spectrometry (IS), the simultaneous acquisition of images in many narrow contiguous spectral bands throughout the visible and solar-reflected infrared portions of the spectrum, are discussed. The motivation for IS is reviewed, and the performance of IS is examined, describing prototype sensors. The analysis of IS data is addressed, including the problem of visual interaction with hyperspectral images and their statistical properties, and the effect of data dimensionality on multispectral scene classification. A test of the capability of imaging spectrometry to identify minerals is reported.

Vane, G.↗

Workshop on The Earth as a Planet

Topics addressed include: remote sensing; petrology; imaging spectroscopy; structural properties; thermal evolution; Earth mantle; early Earth; and megageomorphology.

Ashwal, Lewis↗

Multibeam 1.4-GHz Pushbroom Microwave Radiometer

Airborne prototype of multiple-beam pushbroom microwave radiometer (PBMR) developed to advance radiometric technology necessary for remote sensing of geophysical parameters. Instrument used in several joint Langley Research Center/United States Department of Agriculture soil-moisture flight experiments in Virginia, Texas, and California. Data from experiments used to modify, develop, and verify algorithms used to predict soil moisture from remote-sensing measurements. Image data useful in study of effects of characters of beams on radiometer imaging data.

Lawrence, Roland W.↗

Thematic Conference on Remote Sensing for Exploration Geology - Methods, Integration, Solutions, 7th, Calgary, Canada, Oct. 2-6, 1989, Proceedings. Volumes 1 & 2

Recent advances in airborne and satellite remote-sensing technology for application to geological exploration are discussed in reviews and reports. Sections are devoted to basement tectonics and their surface expressions, spectral geology, hydrocarbon exploration applications, radar applications and future systems, engineering and environment issues, geobotanical remote sensing, advanced image processing, data integration and mapping, and mineral exploration. Extensive diagrams, graphs, and sample images are provided.

Source record↗

Initializing Embedded Data Processors From A Single Source

Initial-computer-program-loading system provides startup information to all embedded data processors (EDP's) in general-purpose computer system. Remote processors given image of startup diskette so real local diskette and drive unneeded. System less complex and equipment costs less. Additional benefit, initial program loading tests bus. If boot-up program transmitted correctly, bus assumed to be operating properly.

Chavez, Edward A.↗

Comparison Of Measurments Of Atmospheric Water Vapor

Report presents experimental intercomparison among measurements by four spectrometric instruments for determining concentration of atmospheric water vapor. Three instruments ground-based and needed to provide independent data to calibrate and validate measurements taken by fourth instrument, which is airborne visible/infrared imaging spectrometer (AVIRIS). Remote down-looking instruments like AVIRIS increases accuracy and coverage of water-vapor measurements.

Bruegge, Carol J.↗