135 resultados para Mobile robots -- Remote sensing


Relevância:

100.00% 100.00%

Publicador:

Resumo:

研究多移动机器人的实时运动规划问题,提出了运动规划问题的体系结构,并将最优控制与智能决策相结合,建立实时专家系统,在其支持下,使机器人在时间—能量最优情况下完成规划策略。仿真结果表明该方法具有很强的实时性。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

研究多移动机器人的运动规划问题,在实时运动规划专家系统的基础上提出了一种串级模糊控制器,以校正实际工作环境下各机器人的运动状态与理想情况下可能产生的误差,使各机器人正确调整各自运动状态,达到协调工作的目的。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

由于行走监控在移动机器人技术中的独特地位和作用,使得其问题解决路线与最终性能极大地影响着构成系统的实用性及用户接受程度.本文通过剖析行走监控同其他模块的内在联系,深入地讨论了研究此问题的必要性和困难所在.最后,结合一个实际应用系统,给出了行之有效的指导思想、实现策略和关键问题解决途径。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

研究移动机器人在动态环境中的导航与避障问题。为提高规划的实时性,提出了基于规则的规划方法,将多移动障碍环境机器人的运动规划分解为相对简单的单移动障碍运动规划,利用最优控制来实现单障碍的最优避障,并用智能搜索方法解决了移动机器人在多移动障碍环境中的实时运动规划问题。仿真实例表明了该方法的有效性。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

本文提出的面向任务的机器人语言是为移动机器人提供的一种编程工具。利用环境描述语言和其他灵活的人机对话方式建立环境模型;根据各种不同的性能指标,规划出最佳路径;根据安全等因素自动规划出最佳路径上的行走参数;对来自传感器的信息进行处理,以确定机器人实际位置及障碍情况;引导机器人沿规划好的路径行走,纠正偏差或重新选择避障路径。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

On the issue of geological hazard evaluation(GHE), taking remote sensing and GIS systems as experimental environment, assisting with some programming development, this thesis combines multi-knowledges of geo-hazard mechanism, statistic learning, remote sensing (RS), high-spectral recognition, spatial analysis, digital photogrammetry as well as mineralogy, and selects geo-hazard samples from Hong Kong and Three Parallel River region as experimental data, to study two kinds of core questions of GHE, geo-hazard information acquiring and evaluation model. In the aspect of landslide information acquiring by RS, three detailed topics are presented, image enhance for visual interpretation, automatic recognition of landslide as well as quantitative mineral mapping. As to the evaluation model, the latest and powerful data mining method, support vector machine (SVM), is introduced to GHE field, and a serious of comparing experiments are carried out to verify its feasibility and efficiency. Furthermore, this paper proposes a method to forecast the distribution of landslides if rainfall in future is known baseing on historical rainfall and corresponding landslide susceptibility map. The details are as following: (a) Remote sensing image enhancing methods for geo-hazard visual interpretation. The effect of visual interpretation is determined by RS data and image enhancing method, for which the most effective and regular technique is image merge between high-spatial image and multi-spectral image, but there are few researches concerning the merging methods of geo-hazard recognition. By the comparing experimental of six mainstream merging methods and combination of different remote sensing data source, this thesis presents merits of each method ,and qualitatively analyzes the effect of spatial resolution, spectral resolution and time phase on merging image. (b) Automatic recognition of shallow landslide by RS image. The inventory of landslide is the base of landslide forecast and landslide study. If persistent collecting of landslide events, updating the geo-hazard inventory in time, and promoting prediction model incessantly, the accuracy of forecast would be boosted step by step. RS technique is a feasible method to obtain landslide information, which is determined by the feature of geo-hazard distribution. An automatic hierarchical approach is proposed to identify shallow landslides in vegetable region by the combination of multi-spectral RS imagery and DEM derivatives, and the experiment is also drilled to inspect its efficiency. (c) Hazard-causing factors obtaining. Accurate environmental factors are the key to analyze and predict the risk of regional geological hazard. As to predict huge debris flow, the main challenge is still to determine the startup material and its volume in debris flow source region. Exerting the merits of various RS technique, this thesis presents the methods to obtain two important hazard-causing factors, DEM and alteration mineral, and through spatial analysis, finds the relationship between hydrothermal clay alteration minerals and geo-hazards in the arid-hot valleys of Three Parallel Rivers region. (d) Applying support vector machine (SVM) to landslide susceptibility mapping. Introduce the latest and powerful statistical learning theory, SVM, to RGHE. SVM that proved an efficient statistic learning method can deal with two-class and one-class samples, with feature avoiding produce ‘pseudo’ samples. 55 years historical samples in a natural terrain of Hong Kong are used to assess this method, whose susceptibility maps obtained by one-class SVM and two-class SVM are compared to that obtained by logistic regression method. It can conclude that two-class SVM possesses better prediction efficiency than logistic regression and one-class SVM. However, one-class SVM, only requires failed cases, has an advantage over the other two methods as only "failed" case information is usually available in landslide susceptibility mapping. (e) Predicting the distribution of rainfall-induced landslides by time-series analysis. Rainfall is the most dominating factor to bring in landslides. More than 90% losing and casualty by landslides is introduced by rainfall, so predicting landslide sites under certain rainfall is an important geological evaluating issue. With full considering the contribution of stable factors (landslide susceptibility map) and dynamic factors (rainfall), the time-series linear regression analysis between rainfall and landslide risk mapis presented, and experiments based on true samples prove that this method is perfect in natural region of Hong Kong. The following 4 practicable or original findings are obtained: 1) The RS ways to enhance geo-hazards image, automatic recognize shallow landslides, obtain DEM and mineral are studied, and the detailed operating steps are given through examples. The conclusion is practical strongly. 2) The explorative researching about relationship between geo-hazards and alteration mineral in arid-hot valley of Jinshajiang river is presented. Based on standard USGS mineral spectrum, the distribution of hydrothermal alteration mineral is mapped by SAM method. Through statistic analysis between debris flows and hazard-causing factors, the strong correlation between debris flows and clay minerals is found and validated. 3) Applying SVM theory (especially one-class SVM theory) to the landslide susceptibility mapping and system evaluation for its performance is also carried out, which proves that advantages of SVM in this field. 4) Establishing time-serial prediction method for rainfall induced landslide distribution. In a natural study area, the distribution of landslides induced by a storm is predicted successfully under a real maximum 24h rainfall based on the regression between 4 historical storms and corresponding landslides.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The formation and evolution of magedunes and lakes in Badain Jaran desert is focused by scholars for a long time. In this paper, detailed investigation was made with the Remote Sensing, Geographic Information Systems, climatological data of research region to study the evolution of magedunes, vegetation and lakes. The main conclusions are presented as follows: (1) The magedunes are mainly located in south and northeast of the desert. The density of magedunes decreases from south to north, east to west, and greatest in southeast of the desert. Most of magedunes strike NE30°~60°, and which are NE-SW and NNE-SSW directions. The distribution of magedunes’ strikes indicates that the paleowind of the desert is northwest and west wind. (2) The vegetation cover is low in the Badain Jaran Desert, but there are some well-vegetated areas in the desert, and the value of NDVI is 0.6107. In southeast of the desert, the vegetation degradated seriously from 1987 to 2000. (3) At about 2000, the total area of permanent lakes was 2231.64 hm2 (±5.9%) in southeast of Badain Jaran Desert. From 1960 to about 2000, the lakes changed as followings: in the early 30 years, the area of lakes increased, but after 1990 it decreased. When lakes were large, the toral area of lakes is 20648 hm2 in Badain Jaran Desert, much larger than that of present lakes. (4) From 1961 to 2001, the mean annual evaporation of lakes was 1039.8mm (±10%) in Badain Jaran Desert, and the difference between years was large. The monthly evaporation of lakes was mainly affected by rainfall, temperature. And it was largest in June, 140.9mm(±10%). (5) Based on water balance calculation of present lakes and old lakes in southeast of Badain Jaran Desert, the total precipitation is more than the total evaporation in this area. So it is probable that the precipitation in the lake area supplies water to the lakes, and also to groundwater in west and north part of the desert.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The study of regional crustal stability of active tectonic region basically includes analysis of recent activity of Earth's crust, single factor assessment, study of complexity, and comprehensive assessment of crust stability. In this thesis, some work are made as follows: · Based on abundant data from gravity field, aeromagnetic survey, magnetism, magnetotelluric deep sounding, remote sensing and geotectonic as well as earthquakes observed in recent years around this region and adjacent zones, we can get a through understanding about the structural features and activity of the earth's crust in Chuan-Dian region. The results from explosion earthquake and telluric electromagnetic sounding are consistent with the structural features of the crust manifested by the geophysical field. The data of deep geologic structures are important for us to work out a vivid three-dimensional model of the earth's crustal structure of the Jinsha River region. According to a synthesis, the author of this thesis proposes some indicators for dividing the faulted blocks. It can also be inferred that the movement of the Chuan-Dian faulted block, which is the relatively active part of southwestern China, is controlled by the boundary faults, and the intensive activity and deformation are concentrated along the boundaries of the block. · Mainly discussing respectively the mechanism and laws of active faults, earthquakes, and geological hazards activity, and their influences on the stability and security of engineering, also trying to probe into the way to assess the risk of single factor in this section. Especially with the method of fractal geometry, the thesis has discussed how to study the complexity of each factor. These geologic hazards which are distributed at the uppermost part of the crust in this region form a typical mountainous set of the active tectonic areas. The results of survey show that some slopes are liable- to -sliding with a weak layer of low shear strength. Occurrences of landslides are to a great extent related to local geological structures, in particular active faults. This is why numerous landslides have occurred simultaneously around the epicenter of a strong earthquake or the center of a strong rainfall, which are related to active faults. · The analysis of the crustal stability is based on a regional grid division, and a fuzzy comprehensive analysis method is used to determine the grade of the quality in each grid. The evaluation factors and their weights are taken from the results of the hierarchical analysis. The evaluation indexes consist of qualitative and quantitative ones. The qualitative ones can be quantified through the experts weighing system, while the quantitative ones can be obtained from statistical analysis. For quality grades, four levels are used: stable, essentially stable, sub-stable, and unstable. The results of the evaluation on Jinshajiang region demonstrate that the crustal stability become distinctly worse in the areas controlled by active deep faults. Therefore, detailed investigations on the active faulting and geologic hazards, include earthquake activity are especially necessary for those areas adjacent to the deep fault belts. On the bases of the data available and the survey results, we have made a preliminary assessment for the construction conditions and adaptability of every planned site in the middle or lower reaches of Jinsha River. Finally, the thesis prospected the vista of the study of crustal stability.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The author selected the geological and geochemical characteristics and the genesis of the Dazhuangzi gold deposit in the Pingdu City as the central content of the study. The author summarized geological features of the other gold deposits formed within the same geological setting along the margin of the Jiaolai pull-apart basin and compared these gold deposits with the Dazhuangzi gold deposit. On the basis of the first-hand data obtained from field investigation and from mining production reports, ore-controlling structures, geological characteristics and mineralization regularities of the Dazhuangzi gold deposit are studied in detail. According to the analyzing results of petrochemistry, trace element, rare earth element and fluid inclusion etc., the geochemical characteristics, the genesis and the ore-forming material source of the Dazhuangzi gold deposit and that of the other similar gold deposits along the margin of the Jiaolai Basin are proposed. The study results suggest that the Dazhuangzi gold deposit belongs to the typical interstratified glide breccia type gold deposit, which is controlled by the interstratified glide fault structure located along the margin of the Mesozoic pull-apart Jiaolai basin. The interstratified glide fault structure is in the outer part of unconformity belt between the overlying strata and the basement of the pull-apart basin, being along the marble strata of the Jingshan group. The formation of the ore-controlling structure is related closely with the evolution of the Jiaolai Basin in the Mesozoic. The ore-controlling structure underwent the structural stress changes from compressive to tensional and then to compressive stress with strike slipping features sequentially, which were coincided with the regional tectonic stress evolution. The interstratified glide breccia type gold mineralization mainly occurs in the siliceous-marble breccias and cataclastic rocks within the interstratified glide fault structure. The gold minerogenetic epoch is later than 120Ma when the ore-controlling structure was tensioning and strike-slipping. The occurrences of the ore controlling structure and the gold ore bodies are the same as that of the unconformity belt. The geological and geochemical studies show that the source of the ore-forming material is alike with that of the volcanic rocks of the Qingshan formation, which is widespread in the Jiaolai Basin. Both of them came from the deep crust or even the upper mantle. Based on the geological characteristics and the minerogenetic regularities of the Dazhuangzi gold deposit, a genetic model of the deposit is constructed. In addition, the author used the remote sensing image and exploration results of geochemical and geophysical methods to point out several prospecting areas for further exploration. Through comprehensive study on the interstratified glide fault structure and on the interstratified glide breccia type gold deposits along the Jiaolai pull-apart basin, three types of interstratified glide structures and related gold mineralization are set up according to evolution and distribution of main fault as well as related secondary faults in time and space. They are named as Penjiakuang type, Dazhuangzi type and Fayunkuang type. The author summarized up the minerogenetic characteristics and regularities controlled by these three different types of interstratified glide structures respectively, and set up a general minerogenetic model of the interstratified glide breccia type gold deposit.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

As a typical geological and environmental hazard, landslide has been causing more and more property and life losses. However, to predict its accurate occurring time is very difficult or even impossible due to landslide's complex nature. It has been realized that it is not a good solution to spend a lot of money to treat with and prevent landslide. The research trend is to study landslide's spatial distribution and predict its potential hazard zone under certain region and certain conditions. GIS(Geographical Information System) is a power tools for data management, spatial analysis based on reasonable spatial models and visualization. It is new and potential study field to do landslide hazard analysis and prediction based on GIS. This paper systematically studies the theory and methods for GIS based landslide hazard analysis. On the basis of project "Mountainous hazard study-landslide and debris flows" supported by Chinese Academy of Sciences and the former study foundation, this paper carries out model research, application, verification and model result analysis. The occurrence of landslide has its triggering factors. Landslide has its special landform and topographical feature which can be identify from field work and remote sensing image (aerial photo). Historical record of landslide is the key to predict the future behaviors of landslide. These are bases for landslide spatial data base construction. Based on the plenty of literatures reviews, the concept framework of model integration and unit combinations is formed. Two types of model, CF multiple regression model and landslide stability and hydrological distribution coupled model are bought forward. CF multiple regression model comes form statistics and possibility theory based on data. Data itself contains the uncertainty and random nature of landslide hazard, so it can be seen as a good method to study and understand landslide's complex feature and mechanics. CF multiple regression model integrates CF (landslide Certainty Factor) and multiple regression prediction model. CF can easily treat with the problems of data quantifying and combination of heteroecious data types. The combination of CF can assist to determine key landslide triggering factors which are then inputted into multiple regression model. CF regression model can provide better prediction results than traditional model. The process of landslide can be described and modeled by suitable physical and mechanical model. Landslide stability and hydrological distribution coupled model is such a physical deterministic model that can be easily used for landslide hazard analysis and prediction. It couples the general limit equilibrium method and hydrological distribution model based on DEM, and can be used as a effective approach to predict the occurrence of landslide under different precipitation conditions as well as landslide mechanics research. It can not only explain pre-existed landslides, but also predict the potential hazard region with environmental conditions changes. Finally, this paper carries out landslide hazard analysis and prediction in Yunnan Xiaojiang watershed, including landslide hazard sensitivity analysis and regression prediction model based on selected key factors, determining the relationship between landslide occurrence possibility and triggering factors. The result of landslide hazard analysis and prediction by coupled model is discussed in details. On the basis of model verification and validation, the modeling results are showing high accuracy and good applying potential in landslide research.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Puziwan gold deposit is located at the northern boundary of the North China platform where there are very favorable ore-forming conditions. The deposit is a medium-sized gold deposit associated with silver and copper polymetallic minerallization which were closely related to cryptoexplosive processes and fluidization and underwent multi-epoch superposition of mineralization. The mineralization consists of cryptoexplosive breccia-type, fluidizing-type, porphyry-type, quartz vein-type, etc. The ore-controlling law of ore-bearing brecciated zone is systematically studied in the paper. The shape, scale and attitude of ore bodies are dominat in the upper, the ore bodies of fluidizing breccia-type are dominant in the upper and the middle part, the porphyry-type ore bodies are dominant in the bottom. The quartz vein-type ore bodies are impenetrated in all the brecciated zone. The metallogenic epoch of Puziwan gold deposit is collated and stipulated. The Rb-Sr isochron age of quartz porphyry (wall rock) is 233 Ma, refering to the Ar-Ar age of gold-bearing quartz, excluded the former conclusion that the so-called metallogenic epoch (245.9Ma) is in Indosinian epoch. The nonage metallogenic age of Buziwan gold deposit shoule be in the Yanshanian epoch (142.5Ma). By applying the sub-specimen sampling technique, the Rb-Sr isochron age of gold-bearing pyrites in late mineralization epoch is dated to be 64 Ma. In conclusion, the metallogenetic epoch of Puziwan gold deposit is in late Yanshanian-early Himalayan epoch. On the above basis, the metallogenic model of the "train type" and new texture model of ore deposit are established. by applying the methods of geology, shallow seismic exploration, remote sensing, partial geochemical extraction and the study of inclusions in the late granite porphyry, the author has made the metallogenic progosis in the depth and the prephery of Puziwan gold deposit and eight prospecting targets are proposed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Otindag sandy land and the Guyuan region of Hebei Province lie in the agro-pastoral zone, where sandy desertification is serious. So they are typical for us to study on. In this paper, detail investigation were made on the Remote Sensing, Hydrochemistry, Chronology, grain size analyzing of research region to monitor sandy desertification and environmental background. The main conclusions are presented as following: 1. According to the diverse natural condition, the research area is divided into three types as sandy land desertification, cultivated land desertification and desertification reflected by lake change. The monitoring result of the first type shows that the main performance way of the sandy desertification in Otindag sandy land is that (1) the expansion of both the shifting dune and the half fixed sandy dune, (2) the reduce of the fixed sandy dune. While the result of the second type shows (1) the desertification land in the Guyuan region has first increasing then reducing change for about 30 years. (2) The sand mainly concentrates west of the research area and small part of wind-drift sand distributes northeast the research area with the spot shape. (3) The meadow area increases obviously. As far as the third type, the Dalai Nur lake area occurs first expanding then reducing change and the wind-drift sand around the lake first reduces then increases. 2. The land cover of the different types change with the same law. It is worth notice that the lake area changes oppositely with that of the wind-drift sand. 3. For about 5,000 a B.P. -2800 a B.P., the well developed palaeosols emerged. After that, three layer palaeosols were founded in the profile of Otindag sandy land. The analyses of grain size show that the sand grains of the south were coarser than that of the north. The sand in the north and middle were well sorted, while the south poor sorted. 4. Both the natural and human impact on the process of sandy desertification. On this research result, different regions have different influences. So the measures to improve sandy desertification should be choosed respectively.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Population data which collected and saved according to administrative region is a kind of statistical data. As a traditional method of spatial data expression, average distribution in every administrative region brings population data on a low spatial and temporal precision. Now, an accurate population data with high spatial resolution is becoming more and more important in regional planning, environment protection, policy making and rural-urban development. Spatial distribution of population data is becoming more important in GIS study area. In this article, the author reviewed the progress of research on spatial distribution of population. Under the support of GIS, correlative geographical theories and Grid data model, Remote Sensing data, terrain data, traffic data, river data, resident data, and social economic statistic were applied to calculate the spatial distribution of population in Fujian province, which includes following parts: (1) Simulating of boundary at township level. Based on access cost index, land use data, traffic data, river data, DEM, and correlative social economic statistic data, the access cost surface in study area was constructed. Supported by the lowest cost path query and weighted Voronoi diagram, DVT model (Demarcation of Villages and Towns) was established to simulate the boundary at township level in Fujian province. (2) Modeling of population spatial distribution. Based on the knowledge in geography, seven impact factors, such as land use, altitude, slope, residential area, railway, road, and river were chosen as the parameters in this study. Under the support of GIS, the relations of population distribution to these impact factors were analyzed quantificationally, and the coefficients of population density on pixel scale were calculated. Last, the model of population spatial distribution at township level was established through multiplicative fusion of population density coefficients and simulated boundary of towns. (3) Error test and analysis of population spatial distribution base on modeling. The author not only analyzed the numerical character of modeling error, but also its spatial distribution. The reasons of error were discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

利用被动微波遥感亮度温度数据反演月壤厚度是“嫦娥”探月工程的科学目标之一,也是人类探测月壤厚度的一种新的尝试。深入研究月表太阳辐射、月球内部热流以及月表温度的分布和变化规律,是解译遥感数据,反演月壤厚度的前提条件,也为进一步开展月球探测、开发利用月球资源乃至建立月球基地相关研究工作提供必要的参考。 本文根据月表有效太阳辐照度与太阳常数、日月距离和太阳辐射入射角的关系,建立了月表有效太阳辐照度的实时模型如下: (1) 其中, (2) (3) 通过对月表有效太阳辐照度实时模型的各个参数分析发现,影响月表有效太阳辐照度变化的主要因素是日地距离和太阳辐射入射角的变化。对模型的误差分析表明,从1950年到2050年的100年内,月表有效太阳辐照度计算结果的误差百分比小于0.28%,能更准确地反映月表有效太阳辐照度的变化情况。从2007年月表有效太阳辐照度的计算结果发现,该年内的月表有效太阳辐照度变化在1321.5~1416.6 W•m-2之间,平均为1368.0 W•m-2,一个月内的变化最小幅度为6.0 W•m-2,最大幅度为23.6 W•m-2。 在月表有效太阳辐照度的实时模型基础上,根据能量守恒和Stefan-Boltzmann定律,本文还得出了月表温度分布模型如下: (4) 其中,初始条件由下式决定, (5) 通过与月表温度实际观测结果的比较发现,当月表反射率、热发射率和热惯量分别取0.127、0.94和125 J•m-2•s-1/2•K-1时,模型的计算结果与实际观测值比较符合,能较好地预测理想条件下的月表温度。 月表热参数研究的一个重要应用就是解译对月被动微波遥感的亮度温度数据。在对月被动微波遥感探测中,辐射计获得的亮度温度反映了月球表层的热辐射特性。月球表层的热辐射与其自身的热状况紧密相关,结合文中建立的月表热参数模型,根据辐射传播理论进一步分析了对月微波遥感探测中,月球表层在不同情况下对亮度温度的贡献,确定了亮度温度随月表温度和月壤厚度的变化关系,对被动微波遥感探测月壤厚度的可能性和可能达到的精度进行了估算。 对月球表层的热辐射传播的分析发现,对月被动微波遥感探测获得的亮度温度受月球表层热辐射的控制,与月壤厚度具有指数相关性,并受到月表温度的影响。当月壤和月岩的复介电常数分别为2 + 0.005 j和9 + 1 j、相对磁导率均为1时,对应3.0GHz、7.8GHz、19.35GHz和37.0GHz四个频率的亮度温度与月壤厚度及月表温度的关系可分别近似表示为, 3.0GHz亮度温度: (6) 7.8GHz亮度温度: (7) 19.35GHz亮度温度: (8) 37.0GHz亮度温度: (9) 当月壤厚度和月表温度分别在0.5m~30m和100K~400K之间变化时,上述四个频率的亮度温度变化范围分别在212.5K~252.8K、207.4 K~266.7K、193.8 K~288.6K和174.0 K~310.9K之间。对于较低频率的被动微波遥感,亮度温度随月壤厚度的增大逐渐增大并趋于稳定;对较高频率的被动微波遥感,亮度温度随月壤厚度的增大会产生起伏波动,不利于用单波段反演月壤厚度。亮度温度梯度在频率较高时梯度较大,在很小的月壤厚度范围内很快就趋于0,不利于厚度较大时的月壤厚度反演,但对于厚度较小时的月壤厚度反演精度较高;同时,除3.0GHz外,7.8GHz、19.35GHz和37.0GHz三个频率的亮度温度梯度随月表温度的升高降幅较大,尤其是19.35GHz,适合在夜间对月壤厚度较小的地区进行更精确的探测。对于3.0GHz,其亮度温度梯度受月表温度变化的影响很小,能反映出较深层月壤厚度的信息,可以对月球进行全球全天时探测。若辐射计的分辨率为0.02K,3.0GHz频率对10m厚月壤的判别精度达到0.07m;对于20m厚月壤的精度为1.4m。当月壤厚度小于0.5m时,随着月壤厚度从0到0.5m增加,月球表层的亮度温度贡献呈先减小后增大的趋势,从而使某一亮度温度值可能对应存在两种不同的月壤厚度。因此,对于月壤厚度小于0.5m的区域,利用单波段被动微波遥感亮度温度反演月壤厚度是比较困难的。 在对月被动微波遥感探测中,可以利用月球夜晚时段的亮度温度数据判别月壤厚度是否小于0.5m。当月表温度为100K时,3.0GHz、7.8GHz、19.35GHz和37.0GHz四个频率的亮度温度判别参考值分别为212.9K、207.4K、193.5K和174.1K;月表温度为240K时,上述四个频率的亮度温度判别参考值分别为220.8K、226.8K、234.1K和237.2K。当亮度温度小于参考值时表示月壤厚度小于0.5m,反之,表示月壤厚度大于0.5m。更进一步地,可以根据月表温度的影响系数对月岩是否裸露于月表进行判断。当3.0GHz、7.8GHz、19.35GHz和37.0GHz四个频率的月表温度影响系数接近0.77、0.82、0.84和0.85时,可以认为月岩直接暴露于月表。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

用遥感(Remote Sensing, RS)进行小比例尺的土地动态监测已是比较成熟的技术,随着“3S”技术的发展,如何用“3S”技术进行县级1:10000大比例尺土地利用动态监测是一个新课题,本文以国家“九五”重点科技攻关课题为基础,提出用“3S”技术进行县级土地利用动态监测的技术路线:用RS发现靶区;GPS实测变化地块数据,保证精度;GIS做为集成平台,进行土地数据的日常管理。在包头示范区,用“3S”技术进行县级1:1万大比例尺土地利用动态监测取得了圆满成功:RS“靶区”发现率在92%以上;GPS实测精度在2M以内;选国产GIS软件MAPGIS,进行二次开发而成的县级土地利用动态监测系统界面友好,功能强大。实现证明用“3S”技术进行县级土地利用动态监测方法具有明显的优势。本文对用“3S”技术进行县级土地利用动态监测的技术路线,和实施过程作了较详细的说明。