摘要:

Formulas are given to convert land-based vegetative canopy spectral reflectance measurements into Landsat digital counts in the four channels for a clear standard atmosphere. These formulas are shown to predict the curves found by plotting multitemporal Landsat trajectories. With correct interpretation, plots of channel 3 versus channel 4 Landsat data for crops are shown to yield information on both crop identification and crop leaf area index.

ISSN:0143-1161    

DOI:10.1080/01431168108948337

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Natural vegetation can be effectively classified and stratified for resource inventory purposes in a Landsat-based automated procedure which utilizes three key elements of photointerpretation—tone, texture and terrain. Inventory analysis is accomplished by employing information derived from registered spectral and digital terrain databases. Tonal information is supplied by one or more Landsat digital images, and textural information is derived from the spectral data as the standard deviation of brightness values within a small window moving across the Landsat image. Terrain data are obtained from the U.S. National Cartographic Information Center digital terrain tapes, containing information derived from 1:250 000 topographic maps. These data are used to construct a digital terrain model from which elevation, slope angle, and slope aspect are obtained. The stratification procedure uses an unsupervised clustering algorithm to identify a large number of narrowly defined classes in the multichannel database which are merged and labelled according to their spectral characteristics and spatial relationships. Terrain channels may be used directly in the clustering procedure, or may be used in a concurrent procedure to model ecological relationships between strata and the landscape elements they prefer. Terrain data may also be used to correct for varying illumination due to topography

ISSN:0143-1161    

DOI:10.1080/01431168108948338

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Spectral reflectances of several crops at Phoenix, Arizona were measured during two growing seasons using a hand-held radiometer, the Exotech Model 100A, that had a spectral bandpass configuration similar to scanning radiometers aboard Landsat 2 and 3. During the period of grain filling, yields of two wheat and one barley variety were well correlated with the integrated daily values of a modified vegetation index derived from reflectances in MSS Bands 5 and 7 (0.6-0.7 and 0.8-1.1 μm respectively). The derived model accounted for 88 per cent of the variability in yields from 103 to 656 g/m2which were due to differential experimental soil moisture conditions (20 to 70 cm applied water).

ISSN:0143-1161    

DOI:10.1080/01431168108948339

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Two methods of developing land-cover classifications using Landsat multispectral data were compared. The first method, called P-l, uses a semi-automated approach to develop training statistics which characterize the land-cover types. The second, called multicluster blocks, depends more on analyst interaction to produce the training statistics used by the classifier. The results showed that P-l performed as well as the multicluster-blocks approach on a mountainous study area in southwestern Colorado

ISSN:0143-1161    

DOI:10.1080/01431168108948340

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The Fraunhofer line discriminator (FLD), an airborne electro-optical instrument designed to measure solar-stimulated luminescence, has a sensitivity approaching that of current laboratory fluorescence spectrometers. The feasibility of using an airborne FLD for detection of near-coastal and open-ocean phytoplankton was established by using a laboratory fluorescence spectrometer to measure the luminescence of phytoplankton and to determine the minimum concentration detectable with an FLD

ISSN:0143-1161    

DOI:10.1080/01431168108948341

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The reflectance of shallow water areas to solar illumination is a function of the water depth, the water optical properties and the bottom reflectance. Assuming the water optical properties to be uniform over a given scene area, the signals recorded by a multispectral scanner system may be combined to obtain information on the water attenuation and bottom reflectance parameters without knowledge of the water depth. These techniques are described and evaluated for a test site near North Cat Cay in the Bahamas.

ISSN:0143-1161    

DOI:10.1080/01431168108948342

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168108948344

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168108948345

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168108948347

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor