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Gao M.,Key Laboratory of 3D Information Acquisition and Application | Gao M.,Key Laboratory of Resources Environment | Gao M.,Capital Normal University | Gong H.,Key Laboratory of 3D Information Acquisition and Application | And 11 more authors.
GIScience and Remote Sensing

The uneven distribution of solar radiation due to topographic relief can significantly change the correlation between reflectance and other features such as biomass in rugged terrain regions. In this article, we use the transfer theory to improve the Minnaert approach. After comparing topographic correction methods for Landsat 8 Operational Land Imager (OLI) and EO-1 Advanced Land Imager (ALI) imagery acquired from the mountainous region in Beijing, China, we used visual inspection, statistical analysis, and correlation analysis to evaluate the algorithms and performance of the proposed Minnaert-E approach. The results indicate that corrections based on non-Lambertian methods have better performance than those based on the Lambertian assumption. The correction performances can be ranked as the Minnaert-E, followed by the Minnaert and the SCS+C corrections, and, finally, the C-HuangWei correction, which performed the worst. We found that the Minnaert-E approach can effectively weaken the influence of terrain relief on pixels and restore the true reflectance of the pixels in the relief area. Further analysis indicates that the Minnaert-E has a better effect on image processing where the slope gradient is restricted to less than 10° or between 30° and 43°. © 2015 Taylor and Francis. Source

Hu Z.,Capital Normal University | Hu Z.,Key Laboratory of Resources Environment | Hu Z.,Laboratory of 3D Information Acquisition and Application | Wang Z.,Tianjin Institute of Urban Construction | And 4 more authors.
Journal of Natural Disasters

In this study, a road flooding information extraction model based on high resolution satellite remote sensing imagery was researched. A road flooding information extraction system was developed through the realization of inter-programming among different software environments by combining remote sensing and geographic information system technologies. First, road information extraction rules were built by analyzing spectral, geometrical and textural characteristics of fused image, which can be generated from original high resolution multi-spectral satellite remote sensing imagery. The rules were utilized to make an object-oriented road information extraction model. Second, with the knowledge of pure water s very low reflecting rate in near and mid-infrared electromagnetic wave band, and considering the complexity caused by different environmental background, an adaptive water information extraction model was built. On above bases, a component-based communication and data sharing mechanism between the application environment of remote sensing and geographic information system was established. An interactive user interface that supports model running was then developed. It can provide a spatial overlap function, extract malfunctioned road from original roads, and apply to systems with specific requirements of road flooding information extraction for correlative works. Source

Qin M.,Capital Normal University | Qin M.,Key Laboratory of Resources Environment | Zhong R.,Capital Normal University | Zhong R.,Key Laboratory of Resources Environment | And 2 more authors.
Proceedings - 2011 19th International Conference on Geoinformatics, Geoinformatics 2011

Soil moisture is an important factor for agricultural production and drought monitoring, and soil moisture retrieval for Tibetan plateau has an important practical significance for global climate change and flood monitoring. In this paper, the radiative transfer progress is built to measure the exchange from the soil surface to vegetation. In order to retrieval the soil moisture, the vegetation optical depth is calculated by microwave polarization difference index (MPDI), and brightness temperature data is obtained by AMSRE L3 data; at the same time, some surface soil parameters such as surface roughness and soil dielectric are estimated by establishing soil dielectric constant model. So the soil moisture result would be calculated by using microwave radiation transfer equation and the soil dielectric constant model. Finally the distribution of the soil moisture on Tibetan Plateau is obtained. © 2011 IEEE. Source

Xing L.,Capital Normal University | Xing L.,Key Laboratory of Resources Environment | Hu D.,Capital Normal University | Hu D.,Key Laboratory of Resources Environment | And 2 more authors.
Proceedings - 2011 19th International Conference on Geoinformatics, Geoinformatics 2011

Typhoon is one of the worst natural disasters in the world. Sustainable development of the social and economic of our country is restricted by the effect of Typhoon. High-intensity rainfall brought by Typhoon is an important factor in the formation of disaster. There are two factors, the hazard of the Typhoon disaster control factors and the vulnerability of the regions Typhoon disaster happened, to evaluate Typhoon disaster comprehensive hazard. The Typhoon disaster hazard evaluation and early warning system is developed using the Development Kit ArcEngine based on COM-GIS and integrating real-time rainfall data from the satellite. Collection and storage of the data of Typhoon, searching and visualization of the path of Typhoon, storage of the location of real-time Typhoon point, early Warning of real-time Typhoon point, forecast of the next Typhoon point, early warning of the path of Typhoon and Typhoon disaster hazard Evaluation functions and so on are realized. It provides scientific basis for the evaluation and forecast of disasters and command decision-making of Typhoon disaster control. © 2011 IEEE. Source

Gong Z.,Capital Normal University | Gong Z.,Key Laboratory of 3D Information Acquisition | Gong Z.,Key Laboratory of Resources Environment | Gong Z.,Base of the State Laboratory of Urban Environmental Processes and Digital Modeling | And 14 more authors.
International Journal of Applied Earth Observation and Geoinformation

Vegetation abundance is a significant indicator for measuring the coverage of plant community. It is alsoa fundamental data for the evaluation of a reservoir riparian zone eco-environment. In this study, a sub-pixel Markov model was introduced and applied to simulate dynamics of vegetation abundance in theGuanting Reservoir Riparian zone based on seven Landsat Thematic Mapper/Enhanced Thematic MapperPlus/Operational Land Imager data acquired between 2001 and 2013. Our study extended Markov model'sapplication from a traditional regional scale to a sub-pixel scale. Firstly, Linear Spectral Mixture Analysis(LSMA) was used to obtain fractional images with a five-endmember model consisting of terrestrialplants, aquatic plants, high albedo, low albedo, and bare soil. Then, a sub-pixel transitive probabilitymatrix was calculated. Based on the matrix, we simulated statuses of vegetation abundance in 2010and 2013, which were compared with the results created by LSMA. Validations showed that there wereonly slight differences between the LSMA derived results and the simulated terrestrial plants fractionalimages for both 2010 and 2013, while obvious differences existed for aquatic plants fractional images, which might be attributed to a dramatically diversity of water level and water discharge between 2001and 2013. Moreover, the sub-pixel Markov model could lead to an RMSE (Root Mean Square Error) of0.105 and an R2 of 0.808 for terrestrial plants, and an RMSE of 0.044 and an R2 of 0.784 for aquatic plantsin 2010. For the simulated results with the 2013 image, an RMSE of 0.126 and an R2 of 0.768 could beachieved for terrestrial plants, and an RMSE of 0.086 and an R2 of 0.779 could be yielded for aquatic plants. These results suggested that the sub-pixel Markov model could yield a reasonable result in a short period. Additionally, an analysis of dynamics of vegetation abundance from 2001 to 2020 indicated that thereexisted an increasing trend for the average fractional value of terrestrial plants and a decreasing trendfor aquatic plants. © 2014 Elsevier B.V. Source

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