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Robert R. J. Mohler Wesley F. Palmer Thomas C. Baker Robert M. Bizzell 《The Professional geographer》1986,38(4):375-382
The development and testing of a computerized technique for utilizing multitemporal Landsat multispectral scanner data to estimate spring small grains acreage are described. The Kauth-Thomas green number transformation is applied to the data prior to application of the pixel-level standardized logic. Four years of data from the U.S. and Canada are used in testing. A comparison of the test results to those of the analyst-intensive procedures indicates a potential for increase in near-harvest estimation efficiency with little sacrifice in accuracy. 相似文献
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Meteor44 is a software system developed at MSFC for the calibration and analysis of video meteor data. The photometric range
of the (8 bit) video data is extended from a visual magnitude range of from 8 to 3 to from 8 to −8 for both meteors and stellar
images using saturation compensation. Camera and lens specific saturation compensation coefficients are derived from artificial
variable star laboratory measurements. Saturation compensation significantly increases the number of meteors with measured
intensity and improves the estimation of meteoroid mass distribution. Astrometry is automated to determine each image's plate
coefficient using appropriate star catalogs. The images are simultaneously intensity calibrated from the contained stars to
determine the photon sensitivity and the saturation level referenced above the atmosphere. The camera's spectral response
is used to compensate for stellar color index and typical meteor spectra in order to report meteor light curves in traditional
visual magnitude units. Recent efforts include improved camera calibration procedures and long focal length "streak" meteor
photometry. Meteor44 has been used to analyze data from the 2001, 2002 and 2003 MSFC Leonid observational campaigns as well
as several lesser showers. 相似文献
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Robert M. Suggs William J. Cooke Ronnie J. Suggs Wesley R. Swift Nicholas Hollon 《Earth, Moon, and Planets》2008,102(1-4):293-298
NASA’s Meteoroid Environment Office has implemented a program to monitor the Moon for meteoroid impacts from the Marshall
Space Flight Center. Using off-the-shelf telescopes and video equipment, the Moon is monitored for as many as 10 nights per
month, depending on weather. Custom software automatically detects flashes which are confirmed by a second telescope, photometrically
calibrated using background stars, and published on a website for correlation with other observations. Hypervelocity impact
tests at the Ames Vertical Gun Range facility have begun to determine the luminous efficiency and ejecta characteristics.
The purpose of this research is to define the impact ejecta environment for use by lunar spacecraft designers of the Constellation
manned lunar program. The observational techniques and preliminary results will be discussed.
The U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged. 相似文献
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