Topographic correction is an important data preprocessing step when land cover classification and quantitative analysis of multispectral data are carried out in mountainous regions. Solar illumination effects may cause variations in reflectance of similar ground features, leading to a possible misclassification due to different topographic positions. Since nearly all surfaces exhibit a varying ...

Introduction Organic osmolytes have been implicated in the pathogenesis of myelinolysis because some of them are accumulated slowly during correction of chronic hyponatremia. I investigated whether there was a topographic correlation between demyelinative lesions and the regional changes of organic osmolytes after rapid correction of chronic hyponatremia. In normal female Sprague-Dawley rats, c...

Landsat data are increasingly used for ecological monitoring and research. These data often require preprocessing prior to analysis to account for sensor, solar, atmospheric, and topographic effects. However, ecologists using these data are faced with a literature containing inconsistent terminology, outdated methods, and a vast number of approaches with contradictory recommendations. These iss...

Proper arrangement of axonal projections into topographic maps is crucial for brain function, especially in sensory systems. An important mechanism for map formation is pretarget axon sorting, in which topographic ordering of axons appears in tracts before axons reach their target, but this process remains poorly understood. Here, we show that selective axon degeneration is used as a correction...

Remote sensing of rugged terrain is hampered by topographic effects on spectral signatures. The purpose of this study was to attempt normalization of the topographic effect encountered when analyzing Landsat Thematic Mapper (TM) imagery in the Rocky Mountains. Two normalization techniques were performed on a subscene of a TM image of Rocky Mountain National Park. The first technique was a band ...

The solar radiation intercepted at a given location on the earth's surface is influenced by surface orientation and sky obstruction by surrounding topographic features. Viewshed models can be used to calculate sky obstruction for any given location on or above a complex topographic surface. We have developed an algorithm for rapid calculation of intercepted solar radiation using a combination o...

A method for the radiometric correction of wide field-of-view airborne imagery has been developed that accounts for the angular dependence of the path radiance and atmospheric transmittance functions to remove atmospheric and topographic effects. The first part of processing is the parametric geocoding of the scene to obtain a geocoded, orthorectified image and the view geometry (scan and azimu...