ISSN:0143-1161    

DOI:10.1080/01431169208904230

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A procedure to recover high resolution spectra without any intervening window from infrared Fourier spectrometer data is presented. The technique relies on the maximum entropy principle in information theory. A parametric autoregressive modelling approach is used. Numerical examples are carried using synthetic spectra computed by an high resolution radiative transfer code. The effect of additive noise is also analysed. The application of the technique to remote sensing of the atmosphere is discussed.

ISSN:0143-1161    

DOI:10.1080/01431169208904231

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A method is proposed for cloud detection over sea using a single infrared channel of a high spatial resolution satellite radiometer. The method combines a spatial coherence test and an absolute threshold test for the temperature field. The threshold for the second test is automatically determined by a histogram analysis of data which were preselected by the coherence test. The coherence test used differs from the classical standard deviation test in the way of the test value computation: the weight of the pixel to be investigated is increased. A simulation shows that under conditions of low cloud cover this makes the proposed coherence test more sensitive than the standard deviation test. When applied to real data the test was also found to be very sensitive compared with visible and IR threshold tests. Cloud cover obtained by the whole method is finally compared with that resulting from the visible andIRhistogram analysis procedure of Phulpinet al. This comparison indicates a high reliability of the proposed method.

ISSN:0143-1161    

DOI:10.1080/01431169208904232

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The aim of this paper is to show the ability of multitemporal short-wave satellite data with high spatial resolution (SPOT data) to characterize crop systems in two ways: (1) description of crop-rotation management by identification of the existing crops and optimization of data acquisition for that purpose; (2) analysis of radiometric time evolution of the crops—evolution of mean response (for radiances and vegetation index) and variability (within and between fields), related to their phenological development, cropping practices and weather conditions. The need for precise corrections of atmospheric effects for multitemporal data series is shown.

ISSN:0143-1161    

DOI:10.1080/01431169208904233

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The purpose of this paper is to describe a procedure for the automatic selection of control-points in remote-sensing images of high-relief terrains for alignment with a reference map. This problem has been found to be of strategic importance whenever remote sensing images have to be integrated in a Geographic Information System (GIS) and processed in real time. The procedure described here is based on the recognition of shadow structures in the satellite image and on their comparison with the computer-generated shadows obtained from the Digital Terrain Model (DTM) of the region. The procedure was developed for a Landsat TM image of the Aurina Valley (in the Pusteresi Alps) with the DTM obtained from an IGM (Istituto Geografico Militare) 1:25000 reference map, but with minor changes it can be extended to other remote-sensing images. Comparison of the shadow structures is performed by similarity evaluation of a simplified model of their shapes described by means ofinertia ellipses.Each pair of shadow structures, recognized assimilarand meeting a number of positional constraints, yields a pair of corresponding points whose coordinates provide input values for determining the parameters in the transformation of the input image into a planimetrically corrected one. The performance and robustness of the method and its boundary applicability are assessed. An example is given in which the automatically-determined control-points are directly inserted in a warping function, with reasonably good results.

ISSN:0143-1161    

DOI:10.1080/01431169208904234

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Data from two long traverses in the chenopod rangelands of arid South Australia were analysed by the moving block association analysis technique to reveal the different plant communities. Discriminant analysis showed that the communities along each traverse had distinctive Landsat MSS reflectivity spectra. A method of constructing a quantitative key to identify community types by their Landsat reflectivities is described. However, the key for one traverse was defective when applied to the second traverse, demonstrating a broad-scale breakdown of reflectance relations. Implications for future work are discussed.

ISSN:0143-1161    

DOI:10.1080/01431169208904235

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Changes in leaf reflectance as water content decreases have been hypothesized to occur in the 1 55-1.75 and 2.08-2.35 μm wavelength regions. To evaluate this hypothesis, studies were conducted on ryegrass (Lolium muitiflorumLam.) and oats (Avena salivaL.), which were grown in a controlled, outdoor situation. Both fully-watered control beds and water-stressed beds were periodically examined with a spectroradiometer calibrated against a reflectance reference of polytetrafluoroethylene. The observed changes correspond to those predicted by stochastic leaf models employed by other investigators (leaf reflection increases in the l.55-l.75μm region as leaf water content decreases). Although the percentage changes in TM bands 1-3 are nearly as great as those found in TM bands 5 and 7, the absolute values of reflectance change are much lower. We believe that these patterns are probably characteristic of a broad range of vegetation types. In terms of phenomena detection, these patterns should be considered in any practical remote sensing sensor scenario.

ISSN:0143-1161    

DOI:10.1080/01431169208904236

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Several methods of producing a thematic map, suitable for forestry inventories, are evaluated as to their relative accuracy and efficiency of production. It is argued that all probability-based methods are founded on assumptions that are always false, and therefore necessarily lead to higher error rates. An alternative non-probabilistic method, the watershed, is put forward as a better solution to the classification problem. In order to fully establish the superiority of the watershed method, a complex mountainous area was deliberately chosen to provide difficult and testing conditions. It is demonstrated that the watershed method is far superior to the traditional probability-based methods, both in respect of the efficiency with which a thematic map can be produced, and its accuracy of classification. With the same data, the accuracy of classification were: hybrid method—77 percent supervised maximum likelihood method—82 percent watershed method—96 percent.

ISSN:0143-1161    

DOI:10.1080/01431169208904237

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The Kosi river fan located in the northern part of India is one of the largest alluvial cones built by any river in the world. This 180 km long and 1501cm wide alluvial cone shows evidence of lateral shift exceeding 140 km during the past 250 years. The Kosi alluvial cone and its adjoining area has been studied in detail by remote sensing techniques. The data have been integrated with the available geological and geophysical information to decipher the causes responsible for the lateral shift of such a high magnitude fan.

ISSN:0143-1161    

DOI:10.1080/01431169208904238

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Rising tidal waters breach a channel-bounding spit at mid-tide to carry cool, saline waters into the ebb-dominant channel of the Ria do Barqueiro. Foam lines form an evolving pointed and curving pattern bounding more and less saline waters, and mark the surface limits of the intrusive front. Repeated measurement by radiometer demonstrate the initial presence of three thermally identifiable water masses, at I6.5°C, 17.5°C and 19.8°C, and the homogenization of temperature in less than half an hour.

ISSN:0143-1161    

DOI:10.1080/01431169208904239

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor