Search NASA⌕ Search

SEARCH · Search NASA

Results for “Landsat imagery”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Use of LANDSAT imagery for wildlife habitat mapping in northeast and eastcentral Alaska

The author has identified the following significant results. Indications are that Alaskan scenes dated later than about September 5th are unsuitable for vegetational analyses. Such fall data exhibit a limited dynamic range relative to summer scenes and the informational content of the data is reduced such that discrimination between many vegetation types is no longer possible.

Laperriere, A. J.↗
NASA NTRS1975

Detection of short-term changes in vegetation cover by use of LANDSAT imagery

The author has identified the following significant results. By using a constant band 6 to band 5 radiance ratio of 1.25, the changing pattern of areas of relatively dense vegetation cover was detected for the semiarid region in the vicinity of Tucson, Arizona. Electronically produced binary thematic masks were used to map areas with dense vegetation. The foliar cover threshold represented by the ratio was not accurately determined but field measurements show that the threshold lies in the range of 10 to 25 percent foliage cover. Montana evergreen forests with constant dense cover were correctly shown to exceed the threshold on all dates. The summer active grassland exceeded the threshold in the summer unless rainfall was insufficient. Desert areas exceeded the threshold during the spring of 1973 following heavy rains; the same areas during the rainless spring of 1974 did not exceed threshold. Irrigated fields, parks, golf courses, and riparian communities were among the habitats most frequently surpassing the threshold.

Turner, R. M.↗
NASA NTRS1977

Land use/land cover mapping (1:25000) of Taiwan, Republic of China by automated multispectral interpretation of LANDSAT imagery

Three methods were tested for collection of the training sets needed to establish the spectral signatures of the land uses/land covers sought due to the difficulties of retrospective collection of representative ground control data. Computer preprocessing techniques applied to the digital images to improve the final classification results were geometric corrections, spectral band or image ratioing and statistical cleaning of the representative training sets. A minimal level of statistical verification was made based upon the comparisons between the airphoto estimates and the classification results. The verifications provided a further support to the selection of MSS band 5 and 7. It also indicated that the maximum likelihood ratioing technique can achieve more agreeable classification results with the airphoto estimates than the stepwise discriminant analysis.

Sung, Q. C.↗
NASA NTRS1977

Snowmapping in southern Norway by use of LANDSAT imagery

The author has identified the following significant results. During the summer seasons of 1975 and 1976, the snow cover was successfully monitored and measured in four basins. By use of elevation distributions for these basins combined with the measured snow cover percentage, the equivalent snow line altitude was calculated. The basins were Boevra, Jostedal, Olden, and Breim.

Odegaard, H.↗
NASA NTRS1977

Application of LANDSAT imagery for snow mapping in Norway

The author has identified the following significant results. During the summer seasons of 1975 and 1976, the snow cover was successfully monitored and measured in the four basins. By using elevation distributions for these basins combined with the measured snow cover percentages, the equivalent snow line altitude was calculated. Equivalent snow line altitude was used in accordance with Mark Meier's definition. Cumulative runoff data were collected for the basins. Tables showing percentage snow cover versus cumulative runoff were worked out for 1975.

Odegaard, H.↗
NASA NTRS1977

The use of LANDSAT imagery in relation to air survey imagery for terrain analysis in northwest Queensland, Australia, volume 1

The author has identified the following significant results. Distinctive spectral signatures discriminated areas underlain by distinctive lithological/stratigraphical units where bedrock either outcrops or is relatively near to surface in the Lady Annie-Mt. Gordon fault zone, the Mary Kathleen, and Dugald River-Naraku areas. Spectral signatures associated with discrete plant communities distinguished different types of superficial deposits over the Cloncurry Plains. Distinctive spectral signatures also revealed the presence and nature of concealed bedrock beneath cover of residuum and superficial deposits where this is relatively thin in the Cloncurry Plains. Major faults were clearly displayed in areas of outcropping and near surface bedrock. Sets of lineaments with preferred orientations were identified in the Lady Annie and Dugald River areas. Known base metal deposits occur along these features.

Cole, M. M.↗
NASA NTRS1977

Use of LANDSAT imagery for soil survey

The author has identified the following significant results. The MSS channels 6 and 7 were considered the best to study the relative tonality of different spectral responses of soils, while channels 5 and 7 were best for natural vegetation, drainage patterns, and land use. Frequency ratio was the recommended index for use when analyzing a drainage pattern quantitatively.

Dejesusparada, N.↗
NASA NTRS1975

Large Area Crop Inventory Experiment (LACIE). Effect of sun angle and haze on generation of LANDSAT imagery

The author has identified the following significant results. When heavy haze was present over a nonvegetated scene, the mean radiance values for all MSS channels were lowered, with the greatest decrease occurring in channels 1 and 2. Over a vegetated scene, any apparent decrease in mean radiance values due to haze may be marked by an increase in mean radiance values which occurred as vegetation increased in vigor during its growth cycle. Mean radiance values for nonvegetated targets (except water) were closely correlated to the changes in sun elevation angle throughout the year. A sun angle correction to a fixed reference data appeared to offer the possibility of compensating for haze covered areas by predicting the mean radiance values which would be closely correlated to the normal sun declination curve.

Chesnutwood, C. M.↗