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Ding S.,Wuhan University | Ding S.,Key Laboratory of Precise Engineering and Industry Surveying | He L.,Hunan City University | Li P.,Wuhan Geomatic Institute
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University

Foundation and rail construction must meet higher accuracy for high-speed railway, in order to effectively control projection distance deformation of a GPS control network and reduce the number of projection zone for the east-west highspeed railways, this paper discusses the processing method for the oblique Mercator projection to be applied to develop uniform plane coordinate system by the basic theoriessuch as ellipsoid transformation, projection from ellipsoid to sphere and spherical cylindrical projection. Through a practical engineering example analysis, we show that the oblique Mercator projection can control the length deformation and meet the 10ppm length deformation per kilometer for control network of nonballasted-track and 25ppm for ballast track, and avoid the divisions of too many projection zones. Comparing withnormal Gaussian projection the oblique Mercator projectionhas more superiorities on the east-west high-speed railway andother route engineering control networks. © 2016, Wuhan University All right reserved. Source

Xiang D.,Wuhan University | Xiang D.,Key Laboratory of Precise Engineering and Industry Surveying | Gong J.,Hubei Qingjiang Hydroelectric Development Co.
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University

Wavelet decomposition scale is directly related to the effect of de-noising. To de-noising of deformation sequence, the authorcombines the information criterion of the time series analysis modeling pricing and the characteristics of Gauss white noise under the wavelet transform, put forward the method thatthe Akaike information criterion was used as quantitativeindex to determine the optimal decomposition scale. The calculation results of examples show that in the Akaike information criterion calculated value to the Minimum, the decomposition scale determinedconform to the distribution of signal-to-noise, de-noising effect is better, and Akaike information criterion was used as quantitative index to determine the optimal decomposition scale is effective, itimprove the convenience of wavelet de-noising in deformation data processing. Source

Zhang Z.,Wuhan University | Zhang Z.,Key Laboratory of Precise Engineering and Industry Surveying
Journal of Geomatics

From the definition of engineering geodesy departure, the development history of engineering measurements is described combining with typical historical data. It is discussed that the relations of development status by engineering geodesy with the rapid progress and great development of science and engineering construction in nearly half a century. The development direction and character of this discipline are pointed out. Development trend of engineering geodesy is proposed. It is prospected that engineering geodesy will be further developed to the macro and micro aspects. Source

Huang J.,Hubei University | Huang J.,Key Laboratory for Urban Geomatics of National Administration of Surveying | Xing C.,Hubei University | Xing C.,Key Laboratory of Precise Engineering and Industry Surveying
Electronics, Communications and Networks IV - Proceedings of the 4th International Conference on Electronics, Communications and Networks, CECNet2014

The problem of crack detection in buildings can be realized by using infrared thermal imaging technology, which is based on the non-contact detection of temperature observation. In this paper, image processing methods of infrared images are described. In addition, a simulation experiment on a building which locates in Wuhan is held to examine the reliability of the methods, and the results show that the theory and methods in this paper have practical significances and can be used for detecting cracks of buildings. © 2015 Taylor & Francis Group, London. Source

Shi J.,Wuhan University | Shi J.,Key Laboratory of Precise Engineering and Industry Surveying | Yuan X.,Wuhan University | Yuan X.,Collaborative Innovation Center for Geospatial Technology | And 2 more authors.
GPS Solutions

We extend the application of real-time kinematic PPP to aerial triangulation using GPS to determine coordinates of the antenna installed on the airplane, using real-time satellite products from IGS and the CNES Analysis Center. In order to verify the performance of real-time kinematic PPP for aerial triangulation, three tests with varying aerial and ground conditions are assessed. Numerical results show that real-time kinematic PPP using IGS real-time products of 5-cm orbit accuracy and 0.1- to 0.3-ns clock precision can provide comparable accuracy for aerial photogrammetric mapping at the scale of 1:1000 as does post-mission kinematic PPP using IGS final products. Millimeter-to-centimeter-level differences and centimeter-to-2-decimeter differences are identified for horizontal and vertical coordinates of ground check points, respectively, in the three tests. The comparison between real-time IGS and CNES products for GPS positioning and aerial triangulation unveils that real-time products with a better clock precision can result in better performance of GPS real-time kinematic PPP as applied to aerial triangulation. © 2016 Springer-Verlag Berlin Heidelberg Source

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