摘要:

The basic tool of geostatistics, the semi-variogram, has been used for quantifying spatial structures of soil and vegetation, as depicted by multiresolution remotely-sensed images. Experimental semi-variograms of two contrasting Mediterranean landscapes were analysed by reference to simple theoretical models (spherical, exponential, allometric). A more general approach based on the superposition of spherical models of similar sills and varying ranges of influences is proposed for the interpretation of complex spatial patterns of natural vegetated landscapes.

ISSN:0143-1161    

DOI:10.1080/01431169408954256

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431169408954248

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0143-1161    

DOI:10.1080/01431169408954249

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The multi-spectral reflectances measured from the satellite lead to soil surface information through models. Since these models arc defined and validated at local scale, where the soil surface is considered to be homogeneous, the usc of the models with satellite multi-spectral reflectances as inputs will create a gap between the corresponding output and the average of the local ill situ outputs.

ISSN:0143-1161    

DOI:10.1080/01431169408954250

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Quantification of the surface covered by a parameter distributed at the soil's surface is a current work in remote sensing. The numerical value obtained is always concerned with the resolution of the sensors. We analyse the usual thresholding procedures in the light of new results on spatialization of models. We give the optimal bounds of the error on quantification due to the heterogeneity of the surface distribution and the sensor's resolution. We define new procedures for quantification of covered surfaces within a pixel.

ISSN:0143-1161    

DOI:10.1080/01431169408954251

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The importance of APAR models for the study of biomass production from space requires an analysis of their performances on natural mixed pixels. This is the objective of present study which gives quantitative values for the role of heterogeneity on the APAR assessment from space. These results show that the accuracy of the APAR as currently computed from satellite data cannot be considered as acceptable. Wegive a new APAR model adapted to heterogeneous pixels.

ISSN:0143-1161    

DOI:10.1080/01431169408954252

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Thresholds derived from statistical inference are used frequently to detect some properties of geometrical distributions. Here, in the case of continental topography, it is shown that an intrinsic physical threshold with a characteristic dimension exists which must be taken into account before applying any standard analysis. For distances ranging from 100m to 100km, the elevation statistical distribution is well approximated by a standard Brownian surface with a fractal dimension D = 2·5. However, this pattern is unable to explain a global drainage. The hypsornetric curve of watersheds is used as an approximation of a drainage profile. Then dealing with continental wide hydrographic basins, it is shown that beyond a threshold around 150km the large-scaleelevation follows a logarithmic trend constrained by two boundary conditions: the sea level and the tectonic ridge.

ISSN:0143-1161    

DOI:10.1080/01431169408954253

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A statistical analysis of topography is performed on a square domain using different sizes of window applied to a Digital Elevation Model covering Southern France. For a given window, a two-dimensional linear drift is defined by fitting a plane through the topography, the direction and magnitude of its slope and the explained variance is then computed. After removing the previously defined linear drift, two-dimensional statistics of the residual topography is used to define the direction of lengthening of the topography called the direction of polarization. The data are evenlydistributed on a space grid of one kilometre. We detect correlations between the mean plane and statistics orientations and the mean drainage pattern. According to this approach, two scale thresholds are detected around 6km and 2 km.

ISSN:0143-1161    

DOI:10.1080/01431169408954254

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

In the Sahelian context, features making up the landscape arc a mixture of intermittent elements which can be described not by a single qualitative characteristic but by a range of complementary and, more often, quantitative characteristics.

ISSN:0143-1161    

DOI:10.1080/01431169408954255

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The differentiability of surfaces on Radar imagery is dependent on the parameters of the imaging system such as wavelength, polarisation, resolution, as well as on soil characteristics, geomorphology, and the geometric conditions during imaging. rn this research, to study the effects of pixel size on geological mapping using C-band data, several images of different resolutions have been simulated from an E-SAR airborne radar image acquired by the German space agency, Deutsche Luft und Raumfahrt (DLR).

ISSN:0143-1161    

DOI:10.1080/01431169408954257

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor