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Deng J.,Wuhan University | Cheng X.,Wuhan SumMap RS Technology Co. | Liao M.,China TopRS Technology Co.
Proceedings - International Conference on Electrical and Control Engineering, ICECE 2010 | Year: 2010

As a new type instruments of aerial remote sensing, the low-altitude unmanned aerial vehicle(UAV) mapping systems with its flexible, convenient and efficient advantages make up the deficiencies of the traditional aerial photography in a small area of large scale mapping, emergency and a new countryside surveying, urban rapid updating, focused region monitoring and so on. For the characteristics of unequal overlap, big swing-tilt angle, using the matching technique that combine SIFT feature matching with least squares matching to achieve automatic and high-precise matching, and availably resolve aerial triangulation difficulty of UAV images. Basing on an analysis of UAV remote sensing system, DPGrid (Digital Photogrammetry Grid) system is presented, the tests showed that matching algorithm of the module is advanced, reliable and accurate adjustment, can meet requirements of production. © 2010 IEEE. Source

Zeng Y.,Chinese Academy of Surveying and Mapping | Van Genderen J.L.,University of Twente | Zhang J.,Chinese Academy of Surveying and Mapping | Wang G.,Chinese Academy of Surveying and Mapping | Wang G.,China TopRS Technology Co.
Proceedings of the 2012 International Conference on Industrial Control and Electronics Engineering, ICICEE 2012 | Year: 2012

Image and data fusion is a process dealing with data and information from multiple sources to achieve refined or improved information for decision making. It has wide applications. When images with a similar acquisition time are used, the expected result is to obtain a fused image that retains the spatial resolution from the panchromatic image and color content from the multi-spectral image, to perform land use/cover classification, or to extract geo-spatial information, which can be used in thematic mapping, as well as the establishment and update of geo-spatial databases; when images with different dates are used, the main purpose of image fusion is to detect the changes over a period of time, which can be employed in disaster monitoring, environmental monitoring, land use/cover change detection, etc. Aiming at the two types of applications, this paper discusses and summarizes the evaluation methods for image fusion performance in the level of pixel-based processing and decision-based processing. It also develops a quantitative analysis method for assessment of the pixel-level image fusion for change detection. This method integrates spectral features and spatial texture features which constitute the most important visual content of an image. The main idea of this method is to compare the image similarity between the regions where changed parcels are located and the regions where there is no change using the similarity measure. The practical application examples of the evaluation criteria are also given. © 2012 IEEE. Source

Pei L.,China TopRS Technology Co. | Yingcheng L.,China TopRS Technology Co. | Yingcheng L.,Chinese Academy of Surveying and Mapping | Yanli X.,China TopRS Technology Co. | And 3 more authors.
IOP Conference Series: Earth and Environmental Science | Year: 2014

In this paper, we focus on the successful applications of accurate and emergent surveying and mapping for high precision light small aerial remote sensing system. First, the remote sensing system structure and three integrated operation modes will be introduced. It can be combined to three operation modes depending on the application requirements. Second, we describe the preliminary results of a precision validation method for POS direct orientation in 1:500 mapping. Third, it presents two fast response mapping products- regional continuous three-dimensional model and digital surface model, taking the efficiency and accuracy evaluation of the two products as an important point. The precision of both products meets the 1:2 000 topographic map accuracy specifications in Pingdingshan area. In the end, conclusions and future work are summarized. Source

Sheng L.,China TopRS Technology Co. | Sheng L.,Henan Polytechnic University | Bai J.,China TopRS Technology Co. | Zhou G.-W.,China TopRS Technology Co. | And 4 more authors.
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2015

South Sea Islands of China are far away from the mainland, the reefs takes more than 95% of south sea, and most reefs scatter over interested dispute sensitive area. Thus, the methods of obtaining the reefs bathymetry accurately are urgent to be developed. Common used method, including sonar, airborne laser and remote sensing estimation, are limited by the long distance, large area and sensitive location. Remote sensing data provides an effective way for bathymetry estimation without touching over large area, by the relationship between spectrum information and bathymetry. Aimed at the water quality of the south sea of China, our paper develops a bathymetry estimation method without measured water depth. Firstly the semi-analytical optimization model of the theoretical interpretation models has been studied based on the genetic algorithm to optimize the model. Meanwhile, OpenMP parallel computing algorithm has been introduced to greatly increase the speed of the semi-analytical optimization model. One island of south sea in China is selected as our study area, the measured water depth are used to evaluate the accuracy of bathymetry estimation from Worldview-2 multispectral images. The results show that: the semi-analytical optimization model based on genetic algorithm has good results in our study area; the accuracy of estimated bathymetry in the 0-20 meters shallow water area is accepted. Semi-analytical optimization model based on genetic algorithm solves the problem of the bathymetry estimation without water depth measurement. Generally, our paper provides a new bathymetry estimation method for the sensitive reefs far away from mainland. Source

Bai J.,China TopRS Technology Co. | Zhao Y.,China TopRS Technology Co. | Lin S.,China TopRS Technology Co. | Lin S.,Henan Polytechnic University | And 2 more authors.
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2015

To fully grasp the nature and human geography situation information, solve the problem of ecological environment, economic and social development of the country, monitoring the state of geographic condition by uniform index system has great significance. By collecting the existing standard documents, our paper established a suit of index system considering the characteristics of long time series remote sensing data. The index system includes basic, subject, composite statistical indexes, and statistical indexes based on basic geographic element. The spatial and temporal distribution of geographic condition with Landsat TM image in Haidian district of Beijing from 1983 to 2013 are studies. Results show that farmland decreases by 28.60%, build-up land increases by 38.95% in this period. The amount of land resources in different elevation/slope shows that, with the increase of elevation/slope, farmland and build-up land is gradually reduced, while grassland area is gradually increasing. In plains areas of elevation less than 50m and within the scope of the 0 to 3° slope, farmland and build-up land are the main land cover types, and both show the characteristic of tradeoffs. Urban area extended to the west and the north, meanwhile mass center of Haidian also moves to the northwest. The urban compactness decreases and the fractal index increased gradually, reflecting the city saturation degree become reduced, the city boundary becomes complicated gradually. Thecomprehensive land cover dynamic degree after the first decrease and then increases. Finally, based on the above statistic results, the spatial distribution of land cover in 2015 is predicted. Source

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