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At least 397 records · Page 22

Relationship of Thematic Mapper simulator data to leaf area index of temperate coniferous forests

Regional relationships between remote sensing data and the leaf area index (LAI) of coniferous forests were analyzed using data acquired by an Airborne Thematic Mapper. Eighteen coniferous forest stands with a range of projected leaf area index of 0.6-16.1 were sampled from an environmental gradient in moisture and temperature across west-central Oregon. Spectral radiance measurements to account for atmospheric effects were acquired above the canopies from a radiometer mounted on a helicopter. A strong positive relationship was observed between LAI of closed canopy forest stands and the ratio of near-infrared and red spectral bands. A linear regression based on LAI explained 83 percent of the variation in the ratio of the atmospherically corrected bands. A log-linear equation fit the asymptotic characteristic of the relationship better, explaining 91 percent of the variance. The positive relationship is explained by a strong asymptotic inverse relationship between LAI and red radiation and a relatively flat response between LAI and near-infrared radiation.

Peterson, David L.↗

USSR Space Life Sciences Digest. Index to issues 10-14

An index is provided for issues 10 through 14 of the USSR Space Life Sciences Digest. There are two sections. The first section lists bibliographic citations of abstracts contained in the Digest issues covered grouped by topic area categories. The second section provides a key word index for the same set of abstracts.

Hooke, Lydia Razran↗

A near infrared vegetation index formed with airborne multispectral scanner data

A near infrared vegetation index (NIVI) has been formed with the 1.24 and 1.65 micron bands on the NS001 Thematic Mapper Simulator. The NIVI was compared to the more traditional Perpendicular Vegetation Index (PVI) formed with the 0.66 and 0.83 micron bands. The PVI was found to be less susceptible to problems with rock and soil spectral variations than the VIVI.

Elvidge, Christopher D.↗

Rainfall index over oceans derived from SSM/I data

Ths Special Sensor Microwave/Imager radiometer on board the DMSP satellite measured microwave radiation at 19.35, 22.235, 37.0, and 85.5 GHz with a swath width of 1400 km, providing an opportunity to study global precipitation distributions. A monthly averaged rainfall index was derived using only the 19.35 GHz data. It covers the + or - 50 deg portion of the world with a 5 deg x 5 deg grid. The brightness temperature histogram is analyzed to derive the rainfall distribution. Estimates of the freezing level heights and the water vapor contents are utilized to understand the rainfall distribution better. Log normal and gamma distribution functions are fitted to the data and the derived monthly rainfall index compares favorably with historical precipitation patterns.

Chang, A. T. C.↗

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 235)

This publication is a cummulative index to the abstracts contained in Supplements 223 through 234 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number.

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USSR Space Life Sciences Digest. Index to issues 15-20

This bibliography provides an index to issues 15 through 20 of the USSR Space Life Sciences Digest. There are two sections. The first section lists bibliographic citations of abstracts in these issues, grouped by topic area categories. The second section provides a key word index for the same abstracts. The topic categories include exobiology, space medicine and psychology, human performance and man-machine systems, various life/body systems, human behavior and adaptation, biospherics, and others.

Hooke, Lydia Razran↗

Relative water content of Spruce needles determined by the leaf water content index

Leaf relative water content (RWC) is defined as the volume of water in a leaf divided by the volume at full turgor. Using reflectance factors of wavelengths 0.83 micron and 1.6 microns, a Leaf Water Content Index (LWCI) was derived from the Lambert-Beer Law such that LWCI should equal RWC; LWCI was equal to RWC for Picea pungens, Picea rubens, Liquidambar styraciflua, and Quercus agrifolia. Algebraic manipulation shows that R(1.6)/R(0.83) termed the Moisture Stress Index (MSI), is near-linearly correlated to RWC and to the Equivalent Water Thickness (EWT). Five species tested so far had the same relationship between MSI and EWT, but EWT is not a measure of plant water status.

Hunt, E. Raymond, Jr.↗

Shape matching utilizing indexed hypotheses generation and testing

An indexing mechanism is developed as part of an overall scheme called SMITH (shape matching utilizing indexed hypothesis generation and testing) for two-dimensional model-based object recognition. The approach is based on a dynamic programming implementation of attributed string matching, is computationally efficient, and works effectively for both nonoccluded and occluded shapes. Another advantage of this technique is that models may be inserted or deleted with relatively little cost.

Mehrotra, Rajiv↗

Detection techniques using multispectral data to index soil erosional status

Indexing techniques that can be used to detect soil erosion utilizing the known band widths of the Landsat MSS and TM sensors are identified. The indexing techniques focus on iron oxides, clays, and organic matter as properties revealing soil erosional status. For data aquisition, a Collins visible and infrared intelligent spectrometer was used to collect data from 0.4-24 microns. Pressed polytetrafluorethylene was used as the reflectance standard and was aquired at the same time that the sample data were aquired.

Pelletier, R. E.↗

USSR Space Life Sciences Digest. Index to issues 21-25

This bibliography provides an index to issues 21 through 25 of the USSR Space Life Sciences Digest. There are two sections. The first section lists bibliographic citations of abstracts in these issues, grouped by topic area categories. The second section provides a key word index for the same abstracts. The topic categories include exobiology, space medicine and psychology, human performance and man-machine systems, various life/body systems, human behavior and adaptation, biospherics, and others.

Hooke, Lydia Razran↗

JSC document index

The Johnson Space Center (JSC) document index is intended to provide a single source listing of all published JSC-numbered documents their authors, and the designated offices of prime responsibility (OPR's) by mail code at the time of publication. The index contains documents which have been received and processed by the JSC Technical Library as of January 13, 1988. Other JSC-numbered documents which are controlled but not available through the JSC Library are also listed.

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Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 248)

This publication is a cumulative index to the abstracts contained in Supplements 236 through 247 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number.

Source record↗