ISSN:0143-1161    

DOI:10.1080/01431168708948620

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Cet article présente une classification automatique des unités de paysages de la Pointe d'Arçay d'aprés des données Thematic Mapper (TM), avec un algorithme de classification non supervisée d'agrégation autour de centres mobiles, en utilisant non seulement des informations radiométriques du TM mais aussi un certain nombre de caractéristiques texturales des paysages. La qualité de la classification multispectrale est améliorée par l'introduction d'une analyse de texture

ISSN:0143-1161    

DOI:10.1080/01431168708948621

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Estimation of the combined path radiance and sensor offset terms is essential in adjusting multispectral image radiance measurements for band ratioing. Commonly applied techniques for making this estimate have required assumptions or ancillary information regarding the reflectance properties of surface materials. This paper presents a technique that is unique in that it provides absolute (not just relative) statistically-derived estimates without the use of ancillary information. It is termed the regression intersection method (RIM). RIM is based on contrasts between the spectral properties of various homogeneous areas in rugged terrain. These areas are selected by examination of the image data alone. Bispectral regression (first principal component) lines are determined for each area and are projected, in pairs, to intersection points. Ideally, the coordinates of these points must equal the measurements for zero ground radiance since that is the only condition under which spectrally different materials can have the same radiance values. The median result from several site-pair and band-pair comparisons is used in order to statistically mitigate noise and minor variations due to natural variability. Tests show that the method is successful in determining correction values for the image data that result in maximum removal of the topographic effect in ratio images.

ISSN:0143-1161    

DOI:10.1080/01431168708948622

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The purpose of this study was to investigate the effect of topography on LANDSAT satellite data in gently undulating terrain. Gently undulating terrain is in this work defined as terrain dominated by slopes of between 1° and 15°. For three various solar elevations (38°, 44° and 52°) digital LANDSAT MSS and TM data were merged with digital elevation data. In an agricultural region in southern Sweden 135 cultivated fields, 50 pasture sites and 117 forest sites with a total number of 88 800 pixels were studied.The relationship between LANDSAT response variation and topographic parameters within cultivated fields and forest areas was weak. For some pasture covers a topographic effect was identified.

ISSN:0143-1161    

DOI:10.1080/01431168708948623

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Using remote sensing techniques four strandlines parallel to the present coastline were detected in the 16-18 km wide coastal belt of the Saurashtra peninsula in western India. Geochronological studies of themiliolites, the principal deposit of this area, using the230Th/234method, yielded ages ranging from 52 to 235 thousand years. With strong evidence in favour of tectonic instability in the region, the average uplift rates of the standlines are calculated to range from 0-12 to 0p 58 mm/year.

ISSN:0143-1161    

DOI:10.1080/01431168708948624

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Abstract. Spatial and temporal variabilities of microwave brightness temperature over the U.S. Southern Great Plains are quantified in terms of vegetation and soil wetness. The brightness temperatures (TBrpar; are the daytime observations from April to October for 5 years (1979 to 1983) by NIMBUS-7 Scanning Multichannel Microwave Radiometer (SMMR) at 6-6GHz frequency, horizontal polarization. The spatial and temporal variabilities of vegetation are assessed using visible and near-infrared observations by NOAA-7 Advanced Very High Resolution Radiometer (AVHRR), while an Antecedent Precipitation Index (API) model is used for soil wetness. The API model was able to account for more than 50 per cent of the observed variability in TBalthough linear correlations between TB and API were generally significant at the I per cent level. The slope of the linear regression between TE and API is found to correlate linearly with an index for vegetation density derived from AVHRR data.

ISSN:0143-1161    

DOI:10.1080/01431168708948625

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

LANDSAT data are typically available for a number of overpasses during a growing season. There is currently considerable interest in modelling the so-called crop profile for such multitemporal data by a non-linear profile function of some (spectral) index for the spectral bands. The derived coefficients are used in a subsequent allocation procedure. This paper outlines some results obtained from an evaluation of the approach for crop data from the wheatbelt of Western Australia. Specifically, the degree of separation of crop classes from pasture classes, as measured by the discriminant root, is compared for analyses based on the original bands, on various spectral indices and on fitted coefficients from a crop profile function describing the temporal change in these indices. For the data considered, a marked loss of discrimination is found for analyses based on various spectral indices, when compared with those based directly on the corresponding discriminant functions (where the linear combination is not constrained to be the same for each time). Analysis of the coefficients for the non-linear profile functions fitted to the indices results in further loss of separation.

ISSN:0143-1161    

DOI:10.1080/01431168708948626

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

This paper presents an experiment in MSS image interpretation for the systematic observation of glacier surfaces in the Alps. The glacier monitoring potential of visible and near-infrared data is applied here to the surveying of mountain glaciers, characterized by small areas and strong shading because of their typical morphology. The method developed identifies glacier surfaces by evaluating the intensity values of visible images combined with clearness conditions related to exposure, slope and the surface homogeneity of the glacier. Conditions of clarity, in the absence of a digital terrain model, are estimated from the number of saturated pixels in the visible bands. At a higher level, the near-infrared data used to identify snow and ice surfaces inside the glacier boundaries. The paper discusses the performance of the technique developed, as applied to the analysis of a temporal series concerning a group of 11 small glaciers with critical exposure conditions. The results are expressed as areas of glacier and snow-covered terrain in different years, thus enabling trends in regional mass balance to be estimated.

ISSN:0143-1161    

DOI:10.1080/01431168708948627

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

An account is given of the present U.K. Columbus Programme, together with its relational links to the European Columbus Programme and through that into the International Space Station Programme.

ISSN:0143-1161    

DOI:10.1080/01431168708948628

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The development of simple, rugged and cheap instruments for remote sensing work and the transfer of the manufacture of these instruments to Indian industry is described.

ISSN:0143-1161    

DOI:10.1080/01431168708948629

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor