ISSN:0143-1161    

DOI:10.1080/01431168308948538

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

This work deals with visual interpretation of Landsat satellite images covering an area of 27 000 km2around Qena Province, Upper Egypt. Geological, structural lineaments and drainage density maps are constructed. From these maps the significant hydrogeological features are extracted, correlated and utilized in locating some areas of high underground water content.

ISSN:0143-1161    

DOI:10.1080/01431168308948539

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The National Oceanic and Atmospheric Administration recently convened an Advisory Committee to help it begin the process of transferring Landsat from the government to the private sector. This advisory committee is to help NOAA determine the institutional arrangements, technical parameters and economic feasibility of such a transfer. One of the most important and least understood inputs into this process is the market for Landsat products and ground-station equipment. While at present the U.S. government represents a substantial portion of the users of Landsat data, the market for Landsat data and products in developing countries is expected to grow rapidly. However, the use of Landsat in developing countries is not well understood. This paper looks at the use of Landsat in developing countries by examining the match of remote-sensing technology to the resource information needs of these countries.

ISSN:0143-1161    

DOI:10.1080/01431168308948540

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Experimental applications of data from multispectral and other advanced sensors have demonstrated that remote sensing can make a valuable contribution to the monitoring and management of Canada's land resources. More frequent coverage and additional spectral bands on satellites planned for the mid-1980s and beyond will increase the opportunities for regular use of remotely sensed data. To effectively utilize these data in resource management, the remote sensing input must be matched with the resource management systems existing at that time. Thus, it is essential to anticipate the needs of resource management systems of the late 1980s and 1990s, to determine the appropriate role for remotely sensed data and to develop and implement a plan which will yield the remote sensing systems and methodologies necessary to meet the operational resource management requirements

ISSN:0143-1161    

DOI:10.1080/01431168308948541

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

This paper presents several approaches to the use of radar imagery for land use classification of urban and near-urban areas. The use of L(HH) (L band, horizontal transmit and horizontal receive) data is emphasized because it is these types of data obtained by Seasat-A (and in November 1981 by Shuttle radar) which are most generally available. For urban area studies using imaging radar the effect of processing in an off-zero doppler (‘squint’) mode, the presence of large diffuse scatters and the possibility of height measurements are discussed. Each approach provides information and also requires supporting ground truth which are unique to radar remote sensing. For some areas the coupling of data from the microwave portion of the spectrum to the data available in the visible and near visible realms may improve the classification of urban and near-urban land use. However, the radar data are not without their own limitations which may be imposed by either the system or the nature of the imaged scene. A proper knowledge of these limitations can permit us to turn a perceived defect into a decided advantage. The metropolitan area of Los Angeles provides the geographic background for this study.

ISSN:0143-1161    

DOI:10.1080/01431168308948542

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Analysis of the Mapping Sciences Education Data Base revealed numerous interesting characteristics of the United States' remote sensing education system. Approximately 88 per cent of the education takes place in public supported universities and 90 per cent of this coursework in departments with graduate programmes of study. The majority of this education (37 per cent) is performed by social science departments with geography being the primary sponsor (36 per cent). Unfortunately, most of the 691 remote sensing and airphoto interpretation courses offered nationwide are provided as service courses at an introductory level. This makes it difficult to specialize in remote sensing at the graduate level. The specific types of courses offered and their geographic distribution are summarized. Many of the aforementioned topics are compared with statistics for other mapping sciences including photogrammetry, cartography, surveying, geodesy and geographic information system education. Examination of the remote sensing system in the United States revealed that accurate statistics are needed on (i) the number of courses, their content and enrollment, (ii) the conceptual models used, (iii) degrees or certificates offered, (iv) availability of hardware and software resources and (v) the status of remote sensing as a developing science. Observations on these topics are presented.

ISSN:0143-1161    

DOI:10.1080/01431168308948543

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The reflectance of a vegetation canopy is primarily determined by its leaf area index (LAI), the one sided leaf area per unit area of ground, which in turn is usually correlated to the concentration of chlorophyll (the total chlorophyll per unit area of ground) within the canopy|This laboratory experiment on the growth of curled cress Lepedium sativum (L), indicated that during moisture stress there was no correlation between chlorophyll concentration and LAI and therefore no correlation between chlorophyll concentration and canopy reflectance.

ISSN:0143-1161    

DOI:10.1080/01431168308948544

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The leaf inclination-azimuth angle distribution is a major determinant of the electromagnetic response of vegetation canopies. In field and modelling studies, researchers commonly assume that (i) leaf orientation can be described by two separate distributions of inclination and azimuth angles, (ii) the leaf inclination angle distribution of a particular vegetation type and growth stage is diurnally static and (iii) the leaf azimuth angle distribution is symmetric. In this study the three-dimensional orientation of leaves described as a leaf inclination-azimuth angle distribution plotted in polar co-ordinates was measured throughout a day for a cotton and a soybean canopy. The results and the literature review showed that this distribution can vary significantly on a diurnal basis due to vegetation type, heliotropic leaf movement, environmental conditions (e.g. wind) and vegetation stress (e.g. water stress). The study also showed that it is erroneous to treat two separate distributions of azimuth and inclination angles rather than one three-dimensional distribution of leaf orientation. The three-dimensional distribution needs to be routinely collected in diurnal sun angle studies and incorporated into mathematical models of sensor response.

ISSN:0143-1161    

DOI:10.1080/01431168308948545

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The red edge is the sharp change in leaf reflectance between 680 and 750 nm and has been measured on leaves of a variety of species by first derivative reflectance spectrophotometry. A parameter λrewas defined as the wavelength of maximum slope and found to be dependent on chlorophyll concentration (p<0.001), with additional effects of species, developmental stage, leaf layering and leaf water content. The maximum slope parameter was found to be independent of simulated ground area coverage. Often two λrecomponents were identified and both showed a linear relationship with the chlorophyll content of the leaves. The results have been interpreted in terms of Beer's Law and Kubelka-Munk theory. The chlorophyll concentration dependence of λreseems to be explained in terms of a pure absorption effect, and it is suggested that the existence of two λrecomponents arises from the additional factor of leaf scattering properties. In comparison to broad band reflectance, the results indicate that red edge measurements will be valuable for assessment of vegetative chlorophyll status and leaf area index independently of ground cover variations, and are particularly suitable for early stress detection.

ISSN:0143-1161    

DOI:10.1080/01431168308948546

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Foliar water stress in a mature soybean canopy, manifested as wilt rather than as a reflectance shift, was studied using reflectance measurements for Thematic Mapper bands 3 (0.63-0.69 μm), 4 (0.76-0.90 μm) and 5 (1.55-1.75μm). Diffuse and total reflectances were determined using polarization measurements and compared statistically at a variety of look angles at 15min intervals from about 09.00 until 14.00 hours EST. Plots of the data from unstressed canopy show that the behaviour of both the diffuse and total reflectances mimics that of the solar radiance curve with time of day, whereas the stressed canopy reflectance data revealed a nearly linear behaviour with a small negative slope. For both the diffuse and total reflectances measured in the nadir position, TM4 was found to be the most responsive spectral band for foliar water stress detection when the water deficit was sufficient to cause wilting, implying that substantial changes in canopy leaf geometry can best be monitored by TM4. TM3 was not found as responsive to the level of foliar water stress which occurred during this investigation. TM5 showed a response intermediate between TM4 and TM3. The results of polarization calculations for TM4 indicated that during the process of wilting, the level of canopy polarization gradually decreased.

ISSN:0143-1161    

DOI:10.1080/01431168308948547

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor