45,945 research outputs found
Application of LANDSAT to the surveillance and control of lake eutrophication in the Great Lakes basin
The author has identified the following significant results. By use of distilled water samples in the laboratory, and very clear lakes in the field, a technique was developed where the atmosphere and surface noise effects on LANDSAT signals from water bodies can be removed. The residual signal dependent only on the material in water was used as a basis for computer categorization of lakes by type and concentration of suspended material. Several hundred lakes in the Madison and Spooner, Wisconsin area were categorized by computer techniques for tannin or nontannin waters and for the degree of algae, silt, weeds, and bottom effects present. When the lakes are categorized as having living algae or weeds, their concentration is related to the enrichment or eutrophication of the lake
Application of LANDSAT to the surveillance and control of lake eutrophication in the Great Lakes basin
The author has identified the following significant results. Computer techniques were developed for mapping water quality parameters from LANDSAT data, using surface samples collected in an ongoing survey of water quality in Saginaw Bay. Chemical and biological parameters were measured on 31 July 1975 at 16 bay stations in concert with the LANDSAT overflight. Application of stepwise linear regression bands to nine of these parameters and corresponding LANDSAT measurements for bands 4 and 5 only resulted in regression correlation coefficients that varied from 0.94 for temperature to 0.73 for Secchi depth. Regression equations expressed with the pair of bands 4 and 5, rather than the ratio band 4/band 5, provided higher correlation coefficients for all the water quality parameters studied (temperature, Secchi depth, chloride, conductivity, total kjeldahl nitrogen, total phosphorus, chlorophyll a, total solids, and suspended solids)
Study to demonstrate the feasibility of and determine the optimum method of remote haze monitoring by satellite
There are no author-identified significant results in this report
Investigation of techniques for correction ERTS data for solar and atmospheric effects
Significant findings during this report period are: (1) The feasibility of using techniques for obtaining and using atmospheric parameter to transform ERTS data into absolute target reflectance was demonstrated. (2) Ground-truth instrumentation must have a dynamic range of 100,000 for obtaining the full set of atmospheric parameters encountered in the field. (3) Atmospheric transmittance for January through May 1973 varied from 13 to 18 percent in the ERTS bands. (4) Energy scattered to the spacecraft from the atmosphere for the March overflight was equivalent to that produced by a target having a reflectance of 11% in band 4, 5% in band 5, 3% in band 6, and 1% in band 7. (5) This atmospheric radiance varies as a function of sun zenith angle (scatter angle) and is predicted to change by 30% for sun angles at the latitude of the Michigan test site. (6) If not removed from spacecraft measurements before computing reflectance of surface targets, this radiance is a major source of error
Investigation of techniques for correcting ERTS data for solar and atmospheric effects
The author has identified the following significant results. A technique is described by which an ERTS investigator can obtain absolute target reflectances by correcting spacecraft radiance measurements for variable target irradiance, atmospheric attenuation, and atmospheric backscatter. A simple measuring instrument and the necessary atmospheric measurements are discussed, and examples demonstrate the nature and magnitude of the atmospheric corrections. Preliminary results indicate that the radiant power measuring instrument will provide one technique for calibrating ERTS-1 data. The March 27, 1973 mission was significant in the NASA C-130 aircraft and ERTS-1 simultaneously passed over the test sites where RPMI's were being deployed to measure solar and atmospheric parameters and site reflectance
New Hampshire civic health index
The Carsey Institute is participating in a study to examine America\u27s civic health. Led by the Conference on Citizenship (NCoC), America\u27s Civic Health Index is an annual study that measures a wide variety of civic indicators, such as community involvement and helping others. New Hampshire is one of six states partnering with NCoC to produce a state-specific report that examines the civic health in the Granite State
The origins and evolution of French costing systems
Includes bibliographical references (p.25-28)
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