Lanzhou Jiaotong University

Powerchina Northwest Engineering Corporation Limited

Shuwen Yang

Zufeng Li

Haowen Yan

Zhixuan Miao

Haixing Shang

Jingzhong Li

Xiaomin Lu

Xiaoning Su

Weifang Yang

Liming Zhang

ShengXue Ke

Qun Zhang

Wei Ren

Gangyi Zhao

Ruixue Li

Guangjun Yi

Tao Tan

Zhao Zhang

Wenjun Zhao

Shengjie Di

Mingbo Liu

A method for controlling engineering projection deformation includes: calculating, based on known coordinates of an engineering key region, a change rate of a length deformation function per kilometer in a first direction caused by a height difference of the engineering key region and a change rate of the length deformation function per kilometer in the first direction caused by a distance from a central meridian of a Gaussian projection zone of the engineering key region; solving a distance between a meridian where a center of the engineering key region is located and a new central meridian; solving an elevation of a compensation projection plane; and performing comprehensive projection deformation compensation based on the elevation of the compensation projection plane and the distance between the meridian where the center of the engineering key region is located and the new central meridian, so as to realize the controlling of engineering projection deformation.

Method and device for controlling engineering projection deformation

Disclosed in the present disclosure is a commutative encryption and watermarking method based on a chaotic system and a zero watermark for vector geospatial data. According to the method, firstly, the vector geospatial data are scrambled and encrypted by using chaotic sequences generated by a composite chaotic system. Then, vector geospatial elements are randomly combined in pairs. A feature matrix is constructed according to the number of vertex coordinates of the vector geospatial elements in combinations, and the parity of the number. Finally, an XOR operation is performed on the feature matrix and the watermark image to construct a zero watermark image, and the zero watermark is constructed through invariant features of the vector geospatial data.

Commutative encryption and watermarking method based on chaotic system and zero watermark for vector geospatial data

A GNSS emergency monitoring error suppression method for an alpine canyon complex environment is provided. Through three steps of GNSS optimization design of the alpine canyon complex environment, derived error suppression of emergency monitoring criteria in the alpine canyon complex environment, and error suppression measurement and result correction, GNSS measurement errors in the alpine canyons can be effectively suppressed. Through improving measurement accuracy, GNSS technology can be widely applied to the alpine canyons, outstanding advantages of high efficiency and high accuracy in a coordinate transmission process of the GNSS technology are brought into full play, and a cost is effectively reduced. Meanwhile, by processing the errors of the emergency monitoring criteria, it is possible to protect workers from on-site operation risks.

GNSS emergency monitoring error suppression method for alpine canyon complex environment

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Lanzhou, China

Shuwen Yang