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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Wheat signature modeling and analysis for improved training statistics: Supplement. Simulated LANDSAT wheat radiances and radiance components

Simulated scanner system data values generated in support of LACIE (Large Area Crop Inventory Experiment) research and development efforts are presented. Synthetic inband (LANDSAT) wheat radiances and radiance components were computed and are presented for various wheat canopy and atmospheric conditions and scanner view geometries. Values include: (1) inband bidirectional reflectances for seven stages of wheat crop growth; (2) inband atmospheric features; and (3) inband radiances corresponding to the various combinations of wheat canopy and atmospheric conditions. Analyses of these data values are presented in the main report.

Malila, W. A.↗
NASA NTRS1979

CCEA second-generation wheat yield model for hard red wheat in North Dakota

The problem of estimating wheat yields for years with unusual planting dates and/or unusual phenological development is investigated. A yield model developed for hard red spring wheat in North Dakota using historical yields for crop reporting districts in conjunction with meteorological predictor variables based on weekly data is assessed.

Leduc, S. K.↗
NASA NTRS1977

Investigations of spectral separability of small grains, early season wheat detection, and multicrop inventory planning

The author has identified the following significant results. LANDSAT data from seven 5 by 6 segments having crop type information were analyzed to determine the potential for spectral separation of spring wheat from other small grains as an alternative to the primary LACIE procedure for estimating spring wheat acreage. Within segment field-center, classification accuracies for spring wheat vs. barley tended to be best in mid-July when crop color changes were in progress. When correlations were made for differences in atmospheric haze, data from several segments could be aggregated, and results that approached within segment accuracies were obtained for selected dates. LACIE field measurement spectral reflectance data provided information on both wheat development patterns and the importance of various agronomic factors on wheat reflectance, the most important being availability of soil moisture. To investigate early season detection for winter wheat, reflectance of developing wheat patterns was simulated through reflectance modeling and was analyzed along with field measured reflectance from a Kansas site. The green component development of the wheat field was analyzed as a function of data throughout the season. A selected threshold was not crossed by all fields until mid-April. These reflectance data were shown to be consistent actual LANDSAT data.

Nalepka, R. F.↗
NASA NTRS1978

Separability study of wheat and small grains

The author has identified the following significant results. Barley showed significant separability from spring wheat, both multitemporally and on a single date chosen near the turning time for barley. Oats showed occasional multitemporal separability from barley and spring wheat; however, the cause of this separability was not well understood. Oats showed no significant separability from spring wheat on any single date during the growing season. By pooling data from segments having an acquisition near the turning time for barley, a fixed unitemporal projection for aiding in the labeling of barley versus spring wheat and oats was constructed. This projection has about the same separability of barley from spring wheat and oats as the unitemporal greeness versus brightness plot. The new fixed projection has the advantage that barley occurs consistently in the same general location on the plot with respect to spring wheat and oats. Attempts to construct a fixed multitemporal or a segment-dependent multitemporal projection for aiding in the labeling of spring wheat versus other small grains were unsuccessful due to segment availability and the fact that each segment has a unique acquisition history.

Lennington, R. K.↗
NASA NTRS1975

United States benefits of improved worldwide wheat crop information from a LANDSAT system

The value of worldwide information improvements on wheat crops, promised by LANDSAT, is measured in the context of world wheat markets. These benefits are based on current LANDSAT technical goals and assume that information is made available to all (United States and other countries) at the same time. A detailed empirical sample demonstration of the effect of improved information is given; the history of wheat commodity prices for 1971-72 is reconstructed and the price changes from improved vs. historical information are compared. The improved crop forecasting from a LANDSAT system assumed include wheat crop estimates of 90 percent accuracy for each major wheat producing region. Accurate, objective worldwide wheat crop information using space systems may have a very stabilizing influence on world commodity markets, in part making possible the establishment of long-term, stable trade relationships.

Heiss, K. P.↗
NASA NTRS1977

Applications of Suits spectral model to wheat

Canopy reflectance calculations for a spring type Mexican wheat, Penjamo, are compared with published data on Scout winter wheat. Good agreement exists between model calculations and experimental data in the spectral range, 500 nm to 750 nm, suggesting that the model parameters for wheat can be applied to different cultivars of wheat in the same growth stage. Wheat canopy reflectance is dependent upon surface soil type and this dependency is examined with the Suits' spectral model. In this particular growth stage wheat reflectance is shown to be nearly independent of soil reflectance in the visible wavelengths and progressively dependent at longer wavelengths in the infrared.

Chance, J. E.↗
NASA NTRS1973

Discrimination of winter wheat on irrigated land in southern Finney County, Kansas

The author has identified the following significant results. Winter wheat in the large field irrigated landscape of southern Finney County, Kansas was successfully discriminated by use of 4 ERTS-1 images. These images were acquired 16 August 1972, 21 September 1972, and 2 December 1972. MSS-5 images from each date and the MSS-7 image from 2 December 1972 were used. Human interpretation of the four images resulted in a classification scheme which produced 98% correct estimation of the number of wheat fields in the training sample and 100% correct estimation in the test sample. Overall correct separation of wheat from non-wheat fields was 93% and 86%, respectively. Offsetting errors resulted in the estimation accuracy for wheat.

Morain, S. A.↗
NASA NTRS1973

Identification of winter wheat from ERTS-1 imagery

Continuing interpretation of the test area in Finney County, Kansas, has revealed that winter wheat can be successfully identified. This successful identification is based on human recognition of tonal signatures on MSS images. Several different but highly successful interpretation strategies have been employed. These strategies involve the use of both spectral and temporal inputs. Good results have been obtained from a single MSS-5 image acquired at a critical time in the crop cycle (planting). On a test sample of 54,612 acres, 89 percent of the acreage was correctly classified as wheat or non-wheat and the estimated wheat acreage (19,516 acres) was 99 percent of the actual acreage of wheat in the sample area.

Williams, D. L.↗
NASA NTRS1974

Estimate of winter wheat yield from ERTS-1

A model for estimating wheat yield per acre has been applied to acreage estimates derived from ERTS-1 imagery to project the 1973 wheat yields for a ten county area in southwest Kansas. The results (41.04 million bushels) are within 3 per cent of the preharvest estimates for the same area prepared by the USDA Statistical Reporting Service (39.91 million bushels). The projection from ERTS data is based on a visual enumeration of all detectable wheat fields in the study area and was completed while the harvest was in progress. Visual identification of winter wheat is readily achieved by using a temporal sequence of images (band 5 for Sept.-Oct.; band 5 for Dec.-Jan.; and band 5 and 7 for March-April). Identification can be improved by stratifying the project area into subregions having more or less homogeneous agricultural practices and crop mixes. By doing this, small changes in the spectral appearance of wheat related to soil type, irrigation, etc. can be accounted for. The interpretation rules developed by visual analysis can be automated for rapid computer surveys.

Morain, S. A.↗
NASA NTRS1974

Feasibility for identification of wheat in Hill County, Montana

Hill County, Montana was the site chosen for feasibility studies concerning wheat crop identification using ERTS 1 multispectral band scanner data, in which the specific objective was to determine whether wheat is spectrally separable from other crops which are typically grown in wheat producing areas. Available computerized techniques were evaluated for their utility in the investigation. It was found that wheat can be separated from other crops with a classification accuracy of roughly 90 percent or better, and that the best single data set occurs after wheat is fully headed and before it turns yellow. The best overall performance was obtained using the three-pass data set using the best 8 channels, or all 12 channels.

Flores, L. M.↗
NASA NTRS1976

United States benefits of improved worldwide wheat crop information from a LANDSAT system overview

The value of improvements in worldwide information on wheat crops provided by LANDSAT was measured in the context of world wheat markets. These benefits were based on exiting LANDSAT technical goals and assumed that information would be made available to the United States and other countries at the same time. The benefits to the United States of such public LANDSAT information on wheat crops were found to be 174 million dollars a year on the average. The benefits from improved wheat crop information compare favorably with the annual system's cost of about $62 million. A detailed empirical sample demonstration of the effect of improved information was developed. The history of wheat commodity prices for 1971-72 was reconstructed and the price changes from improved vs. historical information were compared.

Source record↗
NASA NTRS1977

Suits reflectance models for wheat and cotton - Theoretical and experimental tests

Plant canopy reflectance models developed by Suits are tested for cotton and Penjamo winter wheat. Properties of the models are discussed, and the concept of model depth is developed. The models' predicted exchange symmetry for specular irradiance with respect to sun polar angle and observer polar angle agreed with field data for cotton and wheat. Model calculations and experimental data for wheat reflectance vs sun angle disagreed. Specular reflectance from 0.50 to 1.10 micron shows fair agreement between the model and wheat measurements. An Appendix includes the physical and optical parameters for wheat necessary to apply Suits' models.

Chance, J. E.↗
NASA NTRS1974

Wheat: Its water use, production and disease detection and prediction

The author has identified the following significant results. Discussed in this report are: (1) the effects of wheat disease on water use and yield; and (2) the use of ERTS-1 imagery in the evaluation of wheat growth and in the detection of disease severity. Leaf area index was linearly correlated with ratios MSS4:MSS5 and MSS5:MSS6. In an area of severe wheat streak mosaic virus infected fields, correlations of ERTS-1 digital counts with wheat yields and disease severity levels were significant at the 5% level for MSS bands 4 and 5 and band ratios 4/6 and 4/7. Data collection platforms were used to gather meteorological data for the early prediction of rust severity and economic loss.

Kanemasu, E. T.↗
NASA NTRS1977

Two phase sampling for wheat acreage estimation

A two-phase Landsat-based sample allocation and wheat proportion estimation method was developed. The technique employs manual, Landsat full frame-based wheat or cultivated land proportion estimates from a large number of segments comprising a first sample phase to optimally allocate a small phase-two sample of computer or manually processed segments. Proportion estimates from each phase are then linked by regression or probability proportional to estimated size estimators to provide wheat proportion estimates and standard errors by reporting unit. Application to the Kansas Southwest CRD (Crop Reporting District) for 1974 produced a wheat acreage estimate for that CRD within 2.42% of the USDA SRS-based estimate using a lower CRD inventory budget than for a simulated reference LACIE (Large Area Crop Inventory Experiment) system.

Thomas, R. W.↗
NASA NTRS1979

Large Area Crop Inventory Experiment (LACIE). Phase 3 direct wheat study of North Dakota

The author has identified the following significant results. The green number and brightness scatter plots, channel plots of radiance values, and visual study of the imagery indicate separability between barley and spring wheat/oats during the wheat mid-heading to mid-ripe stages. In the LACIE Phase 3 North Dakota data set, the separation time is more specifically the wheat soft dough stage. At this time, the barley is ripening, and is therefore, less green and brighter than the wheat. Only 4 of the 18 segments studied indicate separation of barley/other spring small grain, even though 11 of the segments have acquisitions covering the wheat soft dough stage. The remaining seven segments had less than 5 percent barley based on ground truth data.

Kinsler, M. C.↗
NASA NTRS1974

ERTS-1 data collection systems used to predict wheat disease severities

The author has identified the following significant results. The feasibility of using the data collection system on ERTS-1 to predict wheat leaf rust severity and resulting yield loss was tested. Ground-based data collection platforms (DCP'S), placed in two commercial wheat fields in Riley County, Kansas, transmitted to the satellite such meteorological information as maximum and minimum temperature, relative humidity, and hours of free moisture. Meteorological data received from the two DCP'S from April 23 to 29 were used to estimate the disease progress curve. Values from the curve were used to predict the percentage decrease in wheat yields resulting from leaf rust. Actual decrease in yield was obtained by applying a zinc and maneb spray (5.6 kg/ha) to control leaf rust, then comparing yields of the controlled (healthy) and the noncontrolled (rusted) areas. In each field a 9% decrease in yield was predicted by the DCP-derived data; actual decreases were 12% and 9%.

Kanemasu, E. T.↗
NASA NTRS1974

ERTS-1 data collection systems used to predict wheat disease severities

The feasibility of using the data collection system on Earth Technology Satellite-1 to predict wheat leaf rust severity and resulting yield loss was tested. Ground-based data-collection platforms (DCPs), placed in two commercial wheat fields, transmitted to the satellite such meteorological information as maximum and minimum temperature, relative humidity, and hours of free moisture. Meteorological data received from the two DCPs from April 23 to 29 were used to estimate the disease progress curve. Values from the curve were used to predict the percentage decrease in wheat yields resulting from leaf rust. Actual decrease in yield obtained by applying a zinc and maneb spray to control leaf rust, and then comparing yields of the controlled (healthy) and the noncontrolled (rusted) areas. In each field, a 9% decrease in yield was predicted by the DCP-derived data; actual decreases were 12% and 9%.

Kanemasu, E. T.↗
NASA NTRS1975

Proceedings of the 1974 Lyndon B. Johnson Space Center Wheat-Yield Conference

The proceedings of the 1974 Lyndon B. Johnson Space Center Wheat-Yield Conference are presented. The state of art of wheat-yield forecasting and the feasibility of incorporating remote sensing into this forecasting were discussed with emphasis on formulating common approach to wheat-yield forecasting, primarily using conventional meteorological measurements, which can later include the various applications of remote sensing. Papers are presented which deal with developments in the field of crop modelling.

Pitts, D. E.↗