[Show abstract][Hide abstract] ABSTRACT: In China, natural disasters are characterized by wide distribution, severe destruction and high impact range, and they cause significant property damage and casualties every year. Following a disaster, timely and accurate acquisition of geospatial information can provide an important basis for disaster assessment, emergency relief, and reconstruction. In recent years, Unmanned Aerial Vehicle (UAV) remote sensing systems have played an important role in major natural disasters, with UAVs becoming an important technique of obtaining disaster information. UAV is equipped with a non-metric digital camera with lens distortion, resulting in larger geometric deformation for acquired images, and affecting the accuracy of subsequent processing. The slow speed of the traditional CPU-based distortion correction algorithm cannot meet the requirements of disaster emergencies. Therefore, we propose a Compute Unified Device Architecture (CUDA)-based image distortion correction algorithm for UAV remote sensing, which takes advantage of the powerful parallel processing capability of the GPU, greatly improving the efficiency of distortion correction. Our experiments show that, compared with traditional CPU algorithms and regardless of image loading and saving times, the maximum acceleration ratio using our proposed algorithm reaches 58 times that using the traditional algorithm. Thus, data processing time can be reduced by one to two hours, thereby considerably improving disaster emergency response capability.
IOP Conference Series Earth and Environmental Science 03/2014; 17(1):012190.
[Show abstract][Hide abstract] ABSTRACT: 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.
IOP Conference Series Earth and Environmental Science 03/2014; 17(1):012182.
[Show abstract][Hide abstract] ABSTRACT: Image fusion is an effective approach to integrate disparate and complementary information of multi-source imagery. How to keep the spectral information while improving the spatial resolution during the fusion process has always been the research focus. As a new type of remote sensing data source, the lately launched ALOS has three sensors on board and its data can be widely used in the fields of surveying and mapping, precise regional land cover observation, disaster monitoring, resources investigation, etc. Image fusion provides the means for effectively integrating and using different and complementary information from different sensors of ALOS. This paper selects the most commonly used and the most predominant image fusion methods for the fusion of data from ALOS PRISM sensor and data from ALOS AVNIR-2 sensor. It comprehensively evaluates the performance of each method by qualitative and quantitative comparison and analysis, then draws the conclusion that HPF is the most effective method for the fusion of ALOS data; while it greatly improves the spatial resolution, the spectral information is preserved to the maximum extent.
Microwave and Millimeter Wave Technology, 2008. ICMMT 2008. International Conference on; 05/2008
[Show abstract][Hide abstract] ABSTRACT: The analytical description of a semi automatic updating process of middle scales topographic maps using VHR satellite images, is the objective of this paper. The proposed method is a combination of manual and automatic procedures based to binary map algebra actions and applied in both, raster and vector types of data. This on going study started in the frame of a bilateral research project, which continues until now.
[Show abstract][Hide abstract] ABSTRACT: Following rapid development of economy in China, great changes also take place in landuse status, especially in the urban area. In order to quickly and truly acquire the information of landuse changes and status in quo, aid the government to scientifically manage the land resource, National Land and Resource Department executes a Landuse RS Monitoring project that began from 1999 and will keep for 12 years. Based on RS data of multi-sources, multi-resolutions and multi-phases, 93 important cities with more than 500,000 populations are monitored using advanced 3S technologies. The article introduces the key technologies of landuse monitoring, including ortho-image production, change automatic detection and fusion methods of multi-sources RS data, etc. The article focus on describing the working flow as below: (1) Choice of RS data: how to choose the best data from multi-source, multi-resolution and multi-phase RS data for different aims; (2) Processing of RS data: introduces the rectification model, GCP distribution rule and fusion method for different RS data; (3) Detection and extraction of changes: introduce the automatically change detection methods, and semi-automatic change extraction methods; (4) Investigation in the field: introduces the aim and means for investigation in the fields; (5) Post-processing. In order to get high quality production, the article also gives the reasonable precision indices for key steps. Finally, the article points out the problems and gives the prospect of this project.
[Show abstract][Hide abstract] ABSTRACT: The triangular irregular network (TIN) is the most commonly used digital elevation models. However, because there is no boundary information contained in LIDAR data, and the LIDAR dataset contains data gaps where water occurs, TIN modeling will only follow the principles of structure, without using any boundary information. Thus, there will be depiction error in TIN modeling when it comes across some special features. This paper reviews the technique of airborne LiDAR Data Collection and Processing, and the use of LiDAR data for DEM generation, with special focus on method of TIN modeling. Two methods will be used to support TIN modeling, one is integration of the breaklines into TIN modeling, and the other one is integration of manual additional points into TIN modeling. In the experiment, some kinds of features and terrain will be used to analysis the validity and necessity of these methods in supporting TIN modeling.
[Show abstract][Hide abstract] ABSTRACT: People's Republic of China is one of the most rapidly developing countries in the world today. There is a great demand on highly actual and accurate spatial information of the whole country, especially of West China which becomes the focus of development of the Chinese government right now and in the next years, but where still not enough topographic maps are available. This raises great challenges to the surveying and mapping community in China. Facing the new challenges the Chinese Academy of Surveying and Mapping (CASM) started its pioneer work early 2002 to explore new techniques and technologies available today toward increasing the map productivity. With import of a CCNS/AEROcontrol system in November 2002, the first DGPS/IMU-based photogrammetric project in China was successfully accomplished jointly by CASM, the Germany-based companies IGI and Techedge. Two photogrammetric blocks of 1:4,000 and 1:20,000 photo scales, respectively, were flown in Anyang, China. Direct georeferencing and integrated sensor orientation were conducted. Results achieved were proven by using ground checkpoints and compared with those of aerial triangulation. Orthophotos generated based on direct georeferencing shows the high efficiency and quality, and thus proved the promise of the new technology. Furthermore several DGPS/IMU-based photogammetric projects was accomplished one by one and a big project of more than 100,000 km2 in the Inner Mongolia will be started in August 2003. The paper presents experiences with DGPS/IMU-based photogrammetry in China. Results achieved in concrete projects are shown and evaluated. Politic and technical specialties in China are discussed. Conclusions outline the potential of DGPS/IMU-based photogrammetric production in China.
[Show abstract][Hide abstract] ABSTRACT: With the development of the Database technology and Geographic Information System technology, the spatial data managing mode go through three stages, entirely File system management, File system and Relation Database System mixed management and entirely Database management. At the same time database model also develop from Relation Model, Object-Relation Model, to Object-oriented Model. At the present time there are two main spatial database management approaches using commercial database. One is using Spatial Data Engine (Such as ArcSDE) in the Relation Database Management System. The other is using Object-Relation Database. Whichever spatial database management approach is used, in practical project we need a set of technics flow about the data preparing, database design, database configuration and tuning. Especially in commercial database, the rational database design, configuration and tuning are more important. In this article the experiment construct a fundamental spatial database system for Tibet province using Geodatabase model of the ArcSDE and the Oracle database management System. Concretely, the main fields are researched as following: (1) Analyse the character of fundamental spatial data including the Digital Orthophoto Map data, the Digital Elevation Modal data, the Digital Raster Graphic data and the Digital line Graphic data. And scheme out a data processing plan for spatial database construction. (2) Rationally Design Database, this process includes the design for Geodatabase model and the design for Oracle database. (3) Configure and tune Oracle database, this process includes the configuration of the table and index of the spatial object and the configuration and tuning of the database initial parameters.
[Show abstract][Hide abstract] ABSTRACT: In 2001, a bilateral project started among the Surv eying Department of the TEI of Athens - Greece, the NRSC of China and "Space Imaging Europe" company with the support of the HGM Service. The objective of this collaboration was the study of the possibility of updating middle sca le topographic maps, using VHR satellite images and the investigation of its practical applicability. A new two years res earch project was launched in June 2003 concerning the study of the improvement in the accuracy of the topographic maps using VHR satellite images. Both research groups in the frame of this second on going collaboration, agreed to condu ct at the same time a common research concerning : a) the investigation of spatial databases generalization t echniques and b) new procedures for multi-scale spa tial databases. The objective of this article is to present all the preliminary work done in the field of the generalization and creation of spatial multi-scale databases.