ISSN:0143-1161    

DOI:10.1080/01431168808954958

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A series of 45 plots of millet and sorghum were installed in Sotuba, Mali, during the 1985 rainy season. They comprised five varietiescommonly found in the surrounding countryside. Radiometric measurements together with phenological observations and leaf measurements were made every 7-10 days. At harvest the biomass was dried and each of its components was weighed.The data analysis shows that the grain-to-straw relationship can vary widely and is less dependent on the species/variety than on the environmental conditions. The comparison of accumulated normalized difference vegetation index (NDVI) versus instantaneous NDVI has shown the superiority of the first one through its higher stability. Total biomass is linearly correlated with accumulated NDVI since the tillering, while the final grain production is better correlated with accumulated NDVI after the booting. Furthermore, the terms of the regression seem to be time dependent.

ISSN:0143-1161    

DOI:10.1080/01431168808954959

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

After a brief general introduction, some fundamental aspects of the microwave remote sensing problem will be discussed. Using a few results of the research work performed in The Netherlands, it is shown that our knowledge of the interaction between microwaves and natural targets did increase considerably. At the same time however, it has to be admitted that a number of questions related to the practical application of microwave remote sensing remain unanswered and therefore further investigations will be necessary.

ISSN:0143-1161    

DOI:10.1080/01431168808954960

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

NOAA produces vegetation indices as part of a project to develop the uses of meteorological satellite data for global agricultural monitoring (Henderson-Sellers et al. 1986). However, no consideration is given to the variability of vegetation indices with the solar zenith angle. This paper focuses on this particular issue. A brief summary of an inversion technique is presented in which raw values of the normalized difference vegetation indices (NDVIs) for a variety of surface-cover types are simulated as a function of solar zenith angle. A relationship between a change in NDVI and solar zenith angle is presented. This relation is used to correct global vegetation index (GVI) data. The results show that for NOAA-7 and NOAA-9 data there is little correction in the neighbourhood of the equator (± 10") but the amount of correction increases with increasing latitude. Such corrections are also shown to be important in data comparison and integration. For example, in comparing the NOAA-6- and NOAA-8-derived NDVI with that derived from NOAA-7 and NOAA-9 for a given date and location the solar zenith angle correction is important.

ISSN:0143-1161    

DOI:10.1080/01431168808954961

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Based on the uni-temporal analysis of Thematic Mapper data, a crop and land use inventory experiment over the French Departement Ardeche is currently being carried out at the Joint Research Centre (JRC), Ispra. The study area is classified almost completely as a "less-favoured area" within the corresponding sectorial policy of the Commission of the European Communities (CEC) Agriculture General Directorate, which imposes restrictive conditions on the use of remotely-sensed data (very small average field size – 0–6–1 ha – and dominance of mountainous and rugged terrain types). Additionally, the climatic and edaphic heterogeneity of the study region required an adequate spatial subdivision into homogeneous agro-physical units in order to cope with local variations in plant or crop phenology. Ground-collected information could be successfully registered to the satellite data. Further analysis however, revealed problems being related to the sampling scheme definition which was designed with respect to sampling theory but did not cope, at the same time, with physical and structural heterogeneities of the study area. Due to these difficulties, an interpretative approach was adopted where, for each zone, a set of important spectral classes was defined by image sampling and cluster analysis. After thematic identification of these clusters, a minimum distance classifier was used to map the information classes to the image domain. Accuracy assessments of the resulting classification were hampered by the insufficiently precise description of some ground observation classes, which also limits the potential application of regression estimate techniques.

ISSN:0143-1161    

DOI:10.1080/01431168808954962

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Differential insolation generally strongly influences the spectral responses of woody areas distributed over hills and mountains, making them difficult to discriminate by means of remote sensing techniques. In this paper, we examine the possibilities of a new method of variance decomposition of Thematic Mapper (TM) data using principal component analyses applied to this problem. The first principal components found for every class of ground truth are assumed as expressing the portions of spectral variance related to different insolation and are therefore not considered in discriminating the forested surfaces of two TM scenes by a minimum distance classifier. The low quality and quantity of the ground information used in the research have forced us to employ them with some restrictions. This leads to overestimation of the classification accuracy evaluated by a final confusion matrix; for this reason, the obtained results cannot be considered definitive.

ISSN:0143-1161    

DOI:10.1080/01431168808954963

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

TM data have been used to study the deltaic depositional systems of the Po and Adige rivers. The identification of sedimentary bodies hat have formed in well-defined depositional environments requires the reconstruction of their morphology. To this end, several interactive processing techniques have been applied to a large volume of Thematic Mapper (TM) data relative to different spectral bands and acquisition dates. When necessary, data integration has also been made. Association of genetically related depositional elements allowed the interpretation of depositional environments and developmental stages in the study area.

ISSN:0143-1161    

DOI:10.1080/01431168808954964

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

On the basis of multispectral SPOT data of a test site in southern Algeria(Djebel Amour) the high correlation of the spectral bands S1 and S2 (green and red) could be demonstrated. Due to this fact, the geological application possibilities by means of standard products (e.g. false colour composite) are strongly decreased. The application of advanced image processing techniques on the basis of the I-H-S colour transform, however, enable an improved presentation of subtle spectral differences and, therefore, a better differentiation of geologically relevant phenomena.

ISSN:0143-1161    

DOI:10.1080/01431168808954965

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Investigations have been carried out in the Wadi Araba–Jordan Graben area to trace the relationship between diagnostic signals received from Landsat Thematic Mapper (TM) data and several mineralized ground districts. To meet the objectives, different approaches, involving ratioing, principal component analysis and IHS-decorrelation processing, are used to enhance diagnostic features associated with hydrothermally altered areas. Using ratio techniques the best suited approach is given by a colour combination of band ratios 5/7, 4/3 and 7/4. In principle, comparable results can be generated by a combination of the principle components (PCs) 2, 4 and 3 in this succession. However, the ratio and PC approaches often fail to accentuate clearly the diagnostic features. Main reasons are attributable to similarities in relative intensities of vegetation and minerals and to disadvantages that arise through the techniques themselves. Decorrelated and filtered colour composites of TM bands 1, 4 and 7 have proved to be more successful for delineation of known and unknown mineralizations by the presence of alteration guide minerals such as iron oxides and phyllosilicates. In addition, the resulting final products of the decorrelation concept can be used for carefully directed field work, as spectral and structural information are enhanced simultaneously.

ISSN:0143-1161    

DOI:10.1080/01431168808954966

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Brittle and plastic deformations of the Tunisian Atlas were studied using Landsat data, Seasat synthetic aperture radar (SAR) data and field surveys. Locations of structural stations were guided by detailed analysis of images and computer compatible tapes (CCTs). Digital processing and enlargements at scales of 1:100 000 and 1:200 000 allowed the recognition of several fault displacements and strata dips, followed by field checks. This paper presents an original and complete structural map of the Tunisian Atlas for the first time, showing the en échelon pattern of the major folds and the numerous fault systems.The kinematic evolution of the Tunisian Atlas is shown through the integration of remotelysensed, microtectonic and focal mechanism data. Circular folds, Riedel shears, reverse and tear faults in the Northern Atlas and asymmetrical folds and strikeslip and reverse faults in the Southern Atlas are framed in a new model involving wrench tectonic and induced transpression. Four principal deformational phases, developed from the Palaeogene to the Holocene, have been recognized and discussed. Finally, stress field evolution is presented and compared with plate tectonic knowledge of the Western Mediterranean Basin. The usefulness of remotely-sensed data for this kind of work, with special reference to arid regions, is stressed in this study.

ISSN:0143-1161    

DOI:10.1080/01431168808954967

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor