Showing papers in "Remote Sensing of Environment in 1990"

TL;DR: In this paper, a radiative transfer model based on Allen's generalized plate model is proposed to represent the optical properties of plant leaves from 400 nm to 2500 nm, where spectral refractive index (n) and a parameter characterizing the leaf mesophyll structure (N) are used.

TL;DR: In this article, a method was tested in the semiarid Owens Valley, California for measuring sparse vegetation cover using Landsat Thematic Mapper (TM) multispectral images, where fractions of vegetation, soils, and shading and shadow within the smallest resolution elements (30 × 30 m pixels) were computed by applying a mixing model based on laboratory and field reference spectra.

TL;DR: The use of derivative spectra is an established technique in analytical chemistry for the elimination of background signals and for resolving overlapping spectral features Application of this technique for tackling analogous problems such as interference from soil background reflectance in the remote sensing of vegetation or for resolving complex spectra of several target species within individual pixels in remote sensing is proposed as mentioned in this paper.

TL;DR: The NIR versus red "infrared percentage vegetation index", NIR/(NIR + Red), is functionally and linearly equivalent to the normalized difference vegetation index, (NIR-Red)/(NIR+Red), which is both computationally faster and never negative as discussed by the authors.

TL;DR: In this paper, temperature-independent thermal infrared spectral indices (TISI) are derived from observable thermal infrared radiances, which are as easy to use to perform spectral analysis as reflectances in the visible and near infrared spectral domains.

TL;DR: In this article, the spatial information inherent in digital imagery of a variety of Douglas-fir [Pseudotsuga menziesii (Mirbel) Franco] forest stands in the Pacific Northwest region of the United Stataes was used to exploit the spatio-temporal information.

TL;DR: The relationship between the advanced very high resolution radiometer (AVHRR) normalized difference vegetation index (NDVI) and coniferous forest leaf area index (LAI) over the western United States is examined in this article.

TL;DR: In this article, a comparison of six concurrent Landsat MSS and TM scenes was made to determine the relationship of Landsat digital data with suspended sediments, chlorophyll, and temperature in the surface water of an agricultural lake.

TL;DR: The results show that the fuzzy classifier may enable the extraction of information about individual pixels and about subpixel phenomena not addressed by other classifiers.

TL;DR: In this article, the authors examined the less common phenomenon of an urban heat sink with respect to the mechanism which might explain its formation and found that the phenomenon is regionally pervasive under specific conditions, and quite strong (6.4°C in central Indiana case study).

TL;DR: In this paper, high-resolution reflectance spectra from more than 500 soils were analyzed to determine spectral variability in a portion of the visible and near infrared (0.55-2.32 μm), using a procedure previously developed for study of thermal infrared spectra.

TL;DR: In this article, three techniques for absolute calibration of two reflective channels of the NOAA AVHRR sensors are described and compared and the effect of degradation in the responsivity of the AVHR sensors on vegetation indices are studied.

TL;DR: In this paper, a model of the bidirectional radiance or reflectance of a forest or woodland as remotely sensed by radiometric instruments is proposed, which is based on geometric optics and Boolean models for random sets.

TL;DR: In this paper, the relative bidirectional reflectance factor (BRF) as a function of view angle at a number of solar zenith angles, nadir BRF as a result of solar-zenith angle, and vegetation indices as related to view and solar zeniith angles were investigated over a headed wheat canopy.

TL;DR: In this article, the effect of a frozen soil layer on the microwave signatures of bare soil, carried out measurements on frozen and unfrozen fields in winter, was investigated. But due to the scale height of surface roughness, the models do not agree well with the measurements.

TL;DR: In this article, the authors used multispectral data acquired from an aircraft over large agricultural fields to estimate net radiation (Rn) and soil heat flux (G) using remotely sensed multi-spectral data.

TL;DR: A simple, iterative procedure to determine the optical depth components of the extinction optical depth measured by a solar radiometer is presented in this paper, which improves the determination of the exponent of the Junge law particle size distribution.

TL;DR: In this paper, a high-spectral resolution imagers were used to estimate the fraction of photosynthetically active radiation adsorbed, f(apar), by vegetated land surfaces.

TL;DR: In this paper, an analytical framework is provided for examining the physically based behavior of the normalized difference vegetation index (NDVI) in terms of the variability in bulk subpixel landscape components and with respect to variations in pixel scales, within the context of the stochastic-geometric canopy reflectance model.

TL;DR: In this article, a spectral mixture analysis of Landsat Thematic Mapper (TM) satellite images was used in conjunction with field measurements to examine local and regional-scale environmental processes that covary with the abundance and distribution of vegetation in a semiarid ecosystem.

TL;DR: In this article, the performance of a yield estimation model for sugarcane (Succharum officinarum) was evaluated using spectral and agrometeorological data.

TL;DR: In this article, a two-dimensional radiance model was proposed for interpreting the directional remotely-sensed thermal infrared data obtained over a vegetative surface when the effects of the shadows are minimal.

TL;DR: In this article, the spectral behavior of three varieties if wheat (Anahuac, IAC-24, and BH-1146) was analyzed using field radiometry throughout the 1988 growing season, in the region of Assis, SP.

TL;DR: In this paper, a view-angle correction was derived from ground-based measurements of bidirectional radiance of bare soil, and used to convert nadir ground and aircraft-based data to off-nadir values ( ρ g and ρ a, respectively) for comparison with SPOT HRV data.

TL;DR: Various methods to accurately and efficiently compute gradients, detect edges, and enhance features in satellite data are presented and a set of practical considerations for accurate gradient and/or edge detection in remotely-sensed data is given.

TL;DR: In this article, the authors used a remote sensing approach to produce evapotranspiration (ET) maps for agricultural regions which consist of an array of fields containing different crops at varying stages of growth and soil moisture conditions.

TL;DR: In this article, a class of methods based on a measure of path attenuation that is used to constrain the Hitschfeld-Bordan solution is investigated for lidar, radar, and combined radar-radiometer applications.

TL;DR: The ground-based, X-band radar backscattering of wheat, barley, and oats was investigated through the growing season at VV and HH polarizations, and at incidence angles from 10° to 80°.

TL;DR: In this article, the optical properties of a partially vegetated cotton field with spatially and temporally dynamic soil water conditions were analyzed with coincident aircraft and satellite data, and a soil-adjusted vegetation index (SAVI) minimized both spatial and temporal variations in soil spectral behavior and was found useful in vegetation analysis and in further qualitative assessment of soil condition.

TL;DR: In this article, an algorithm for fast calculation of the visible and near-infrared bidirectional reflectances (R 1 and R 2, respectively) of the ground from NOAA/AVHRR satellite observations is derived.