最新刊期
卷 ， 期 2 ， 1992
- 摘要：This paper presents a remote sensing approach for wheat drought monitoring and modeling, which based on the principles of soil water balance and energy balance. At first, the original soil water content （Wc） was obtained from the relationship of the soil moisture and in apparent thermal inertia which was established through the experiments conducted over nearly bare fields in the North China Plain. Secondly, the evapotranspiration （Et） of the wheat fields was estimated using the remotely sensed reflected solar radiation and surface temperatures extracted from the NOAA-AVHRR digital image as well as the meteorological data such as incoming solar radiation, air temperature, windspeed and vapor pressure from ground meteorological station. Then, the soil water content （Wt） in a particular period of time （say 10 day period） can be calculated using the equation of soil water balance. At last, A drought index model was developed by considering the water requirement of winter wheat and the available soil water content. This model has been proved to be effective in monitoring the wheat drought in a large area.
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发布时间：2021-06-10 - 摘要：Since 1987 the thermal emission from crop canopies has been measured by multi-frequency microwave radiometers designed by Changchun Institute of Geography, Academia Sinica. The relationship between dualpolarized brightness temperature and some related parameters, such as crop height, moisture content, geometric structure, etc., has been experimentally obtained. To quantitatively understand the functional dependence of brightness temperature on those parameters and frequency, polarization, observation angle, we have developed a numerical modeling of radiative transfer for multi-layer random media, which modeled the stratified layers of fruit, leaves and stalks. The newly-derived dual-dispersion model and Polder Van/de Loor formulation are used to calculate the mean dielectric permittivity. All parameters are chosen in a consistent way. The radiative transfer equation for multi-layer random media is derived. By using the discrete-ordinate and eigen analysis methods, numerical results of radiative transfer are obtained, and are favorably compared with the experimental data. The functional relationship between the brightness temperature and various parameters are discussed.
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发布时间：2021-06-10 - 摘要：The Monitoring of dynamic change of forest area in tropical forest vegetation of Xi-shuangbanna Prefecture has been discussed in this paper. There are of two parts being included:1, Using multkemporal remote sensing imagery to interpret forest area change of Xi-shuangbanna Prefecture.In monitoring of the forest area dynamic change, used of multitemporal remote sensing imagery are: （1） aerial photographs Feb-1965; （2） Landsat MSS 02-Mar-1973; （3） aerial photographs Feb-1981; （4） Landsat TM 02-Feb-1988 and Spot XS 16-Feb-1988.According to multitemporal remote sensing imagery interpretation, the forest area in 1965, 1973, 1981 and 1988, of Xishuangbanna Prefecture have been calculated. Results from calculation showed that about 33.72% of the total area of Xishuangbanna Prefecture is covered by tropical and subtropical forest in 1988. But, according to the interpretation of aerial photographs of 1965, the forest area was 46.46% of the whole Prefecture. The comparison of the forest area showed that the decrease rate is about 0.55% per year.2, Using difference imagery to analyse forest area change of nature reserves.Forest area change in nature reserves has been studied by means of digital analysis of Laudsat MSS （1973） and TM （1988） images. An unsupervised classification consisting of principal components analysis fllowed by a clustering procedure was adopted. The normalized difference vegetation index （NDVI） was used as a measure to assess the change in vegetation amount.It was provisionally concluded that degradation of forest area have ceased inside the nature reserve, while outside the nature reserve boundaries, forested area have decreased significantly.The results showed that this method was effective and could be extensive used in renewable resources especially forest vegetation monitoriing.
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发布时间：2021-06-10 - 摘要：The paper presents an united equation for remote sensing quantitative analysis of suspended sediment, of which Gordon equation and negative index equation are included. Other popular equations approximate to it. Many cases show the correlativity and precision of the united equation are higher than those of others. The united equation succeeds in quantitative application of remote sensing in Lingdingyang Ocean of Zhujiang River Estuary.关键词：Suspended sediment;remote sensing;United equation;Zhujiang river estuary
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发布时间：2021-06-10 - 摘要：Remote sensing-biogeochemical indications to oil and gas microseepage in East Hebei province have been studied based on comparative analysis of various trace metal element and adsorbed hydrocarbon content in plant and soil samples between a known oil site and its surrounding background area combined with remote sensing and geophysical prospecting data. It has been shown by the study that content of Ni, Zn, Li, Cr, Mo and Co in the known oil site is higher than in the background area; meanwhile, ground spectral reflection of the mid-infrared waveband in the known oil site is lower than in the back-ground area, which provides a scientific basis for remote sensing-geochemical prospecting of oil and gas in this area.
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发布时间：2021-06-10 - 摘要：The SVD classification algorithm introduced in this paper is designed for remote sensing image processing. It intends to classify an image by simulating the procedure of human visual distinguishing spots. This method could avoid some defeats in normal classifications, decrease the mixture appeared at the edge or the juncture of classes, smooth the homogeneous spots and conserve the small isolate spots. The result of this new method presents advantages of regular spots, clear boundaries and high accuracy. It is obviously better than the results obtained by normal classifications and it is of great value in practical application.
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发布时间：2021-06-10 - 摘要：Based on the analysis of TM imagery covering the loess hilly land and desert land, layer classification and GIS-aided classification have been carried out respectively. After fuzzy reasoning and interactive editing of the classification results, the ’ pure" remote sensing thematic data can be used as the dynamic information source for updating of GIS data-base, and mapping activities can be done with the help of GIS.
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发布时间：2021-06-10 - 摘要：Stereo image matching is the key link in extracting elevation information from SPOT data. Based on the SPOT data analysis of the geometric and the image quality, a new method of multi-level image matching are proposed. Experiments in real image pairs show that, using the method, not only the good precision and the reliability are obtained but also the processing speed is high. The new method can be used to rapidly generate DEM for remote sensing data analysis.
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发布时间：2021-06-10 - 摘要：It is of important significance to use remoe sensing image directly in computer aided cartography. In order to convert remote sensing image data into cartographic data, we must carry out cartographic generalization beforehand.This paper describes in detail a new way of automatic cartographic generalization in microcomputer. With this method, cartographer can control cartographic generalization level conveniently and freely. Once the cartographic generalization level is determined, the machine then completes other work automaticlly.
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发布时间：2021-06-10 - 摘要：GPS cooperative experimental research group by the Institute of Remote Sensing Application Chinese Academy of Sciences, Peking University of Aeronautics and Astronautics, Qing-Hua University, the 3rd Academy of Aeronautics and Astronautics Department, Beijing Industry University has done airborne GPS experiment in Beijing from July to November in 1990.In this paper, Analyses exsiting question of remote sensing information for ground positioning and gives experimental research aim, introduces three airborne GPS flight experiments. At last, forecasts GPS technical application future in remote sensing.
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发布时间：2021-06-10
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