ISSN:0143-1161    

DOI:10.1080/01431168008547548

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The various stages in carrying out a monocluster block unsupervised classification using Landsat MSS data are described. Procedures for carrying out these various stages were found to be far from well-established for the type of terrain being investigated, which is rugged and contains many small land cover units. Two particular difficulties were encountered: firstly, that of precise ground location of pixels; and, secondly, that of objectively evaluating the results. Ways in which these can be surmounted are suggested.

ISSN:0143-1161    

DOI:10.1080/01431168008547549

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Published work on the reflectance of vegetation growing over soil mineralizations is reviewed. Experimental work was carried out on several species grown in a glasshouse and was extended to a pilot field study. In the laboratory studies, the most general effects of Cd, Cu, Pb or Zn were growth inhibition. A detailed study of the leaf pigments of pea plants showed that the chla/chlbratio (chl=chlorophyll) decreased under conditions of Cd or Cu stress but showed little effect with Pb or Zn. However, the absorption spectra of chloroplast pigments were not found to show any wavelength shifts with metal treatments, indicating that new spectral forms of chlorophyll were not produced as a stress response. A decrease in the total chlorophyll content of leaf tissue (fresh weight basis) was correlated with an increase in visible-wavelength leaf reflectance (R) of pea plants.Rat infrared wavelengths of 0.85 μm, 1.65 μm and 2.20 μm decreased in metal-treated plants, compared with controls. Although experiments with other species, and a review of published literature, indicate that reflectance effects are dependent on species, phase of growth cycle and environment, the existence of correlations betweenRat certain wavelengths and the metal concentrations to which roots are exposed was confirmed using oak trees growing naturally in the area of a copper-arsenic mineralization in south-west England. Metal (Cu or As) concentrations in the soil were strongly negatively correlated (p> 99 per cent) withRat 1.65 μm and 2.20 μm, and positively correlated (p> 95 per cent) withRat 0.660 μm, in close agreement with the experiments on pea plants. The inclusion of the relevant infrared bands on Earth resource survey instruments is likely to enhance their usefulness for detecting heavy metal stress in plants.

ISSN:0143-1161    

DOI:10.1080/01431168008547550

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The detectability of settlements and factors influencing their visibility are explored using imagery from two side-looking airborne radar systems. K-band and X-band imagery of diverse areas in the United States are examined to discover the minimum population needed for a settlement to be consistently detected. The percentage of settlements visible by size of population are calculated and omission/commission errors analysed. Particular attention is devoted to the effects of environmental modulation and a near-, mid-, or far-range location, but the factors of scale, resolution, and system are also addressed.

ISSN:0143-1161    

DOI:10.1080/01431168008547551

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The design and calibration of a rugged, low-cost, portable multiband radiometer is described. The instrument measures simultaneously in four bands, the spectral coverage of each being determined by interchangeable absorption filters. Simple band-pass type radiometers are seen to be complementary to conventional spectroradiometers for ground data collection in remote sensing. They have the inherent advantages of portability and speed of operation which make them particularly suitable for fieldwork in areas of complex terrain. An example of the practical use of the instrument to measure the spectral reflectance of partially vegetated surfaces in an area of complex terrain in southern Italy is presented. The increased spectral and spatial resolution of second generation sensing systems will make remote sensing of complex areas more feasible and extensive ground-based spectral measurements in such areas are a necessary step to understanding and utilizing such remotely sensed data.

ISSN:0143-1161    

DOI:10.1080/01431168008547552

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Thermal infrared remote sensing of diurnal crop canopy temperature variations represents a possible method for determining the availability of soil water to plants. This study was performed to assess the effects of soil water and crop canopy on apparent temperatures observed by means of remote sensors, and to determine the impact of these effects on remote soil water monitoring. Airborne thermal scanner and apparent reflectance data (one date) and ground PRT-5 data (three dates) were collected primarily over barley and other small grain canopies. Plant heights, cover, and available soil water for four layers in the top 20 cm were determined. Analysis of the data showed a close inverse linear relationship between the available water and the day minus night temperature difference δT, for thick barley canopies (plant cover above 90 per cent) only. The use of apparent reflectance values in the visible region did not improve available soil water regression equations substantially. These results suggest that the available water or plant stress could only be accurately determined for thick canopies, and that the reflectance data could probably be used to identify such canopies but would not improve regression estimates of soil water from remote sensing data.

ISSN:0143-1161    

DOI:10.1080/01431168008547553

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Remote sensing data, as received from earth resource satellites or obtained through digitization of aircraft photos, are to be processed by means of high efficiency techniques to improve the quality of the data and to obtain final useful results. Two data processing techniques of appreciable interest, namely, data compression and 2-D digital filtering are considered. By means of data compression the amount of data can be reduced solving storage and handling problems, while through 2-D digital filtering correction, enhancement and pattern recognition operations can be performed improving the quality of the data and extracting useful results. Efficient 2-D digital filters of FIR type using the Cappellini window and of IIR type using rotation and stabilization procedures are presented. Data compression techniques using local space operators and 2-D transformations with thresholds and variable length encoding are described. Practical software packages ready for the application of the above techniques are shown. Results obtained by processing through the described techniques satellite data and digitized aircraft photos are presented.

ISSN:0143-1161    

DOI:10.1080/01431168008547554

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

This paper examines the practical contribution of remote sensing to environmental management at the sub-regional scale. The framework for environmental management at a sub-regional scale in the United Kingdom is the County Structure Plan. The Merseyside County Structure Plan seeks to promote the regeneration of older parts of the conurbation whilst safeguarding and enhancing the County's open land. The extent of derelict and despoiled land where development may be promoted is indicated by analysis of panchromatic air photographs. A survey of the quality of residential environments was carried out using colour infrared (CIR) air photography.

ISSN:0143-1161    

DOI:10.1080/01431168008547555

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168008547556

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431168008547557

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor