scholarly journals Feasibility study of high-precision trigonometric elevation replacing second-order level in tunnel penetration control survey

2020 ◽  
Vol 165 ◽  
pp. 04022
Author(s):  
Zhang Hongfeng
Keyword(s):  
Measurement Error ◽  
High Precision ◽  
Feasibility Study ◽  
Error Propagation ◽  
Measurement Accuracy ◽  
Second Order ◽  
Total Station ◽  
Level Measurement ◽  
Control Survey ◽  
Elevation Measurement

Based on the principle of trigonometric elevation measurement and the law of error propagation, the trigonometric elevation formula is derived in this paper. The factors that cause the trigonometric measurement error are analyzed accurately. It is considered that the use of a high-precision total station for the trigonometric elevation measurement under opposite conditions can reach the second-order level measurement accuracy.

scholarly journals The Improvement and application of elevation measurement method with total station

2020 ◽  
Vol 165 ◽  
pp. 03018
Author(s):  
Yiteng Xu ◽  
Xin Zhao ◽  
Hewen Liu ◽  
Feng Xu ◽  
Xiaoqiang Wang
Keyword(s):  
Mathematical Model ◽  
Measurement Error ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Accuracy Analysis ◽  
Error Sources ◽  
Total Station ◽  
Elevation Measurement ◽  
Measurement Efficiency

In this paper, by analyzing the limitations of the traditional trigonometric elevation method, and on the basis of establishing a mathematical model of trigonometric elevation, a convenient and fast trigonometric elevation method without instrument height and prism height is improved, and the operation steps of the method are introduced in detail. The accuracy analysis was evaluated and the method was applied to actual engineering. The results show that under the premise of ensuring the measurement accuracy, this method not only reduces the range of measurement error sources, but also improves the measurement efficiency.

Underwater high-precision ultrasonic water level measurement method for hydraulic physical model

2020 ◽  
Vol 28 (9) ◽  
pp. 2027-2034
Author(s):  
Yue-jie SHU ◽  
◽  
Jun WU ◽  
Yuan-hang ZHOU ◽  
Yu-feng MA ◽  
...  
Keyword(s):  
Water Level ◽  
Physical Model ◽  
High Precision ◽  
Measurement Method ◽  
Level Measurement

Application of Total Station Instrument in the Installation and Measurement of High-Precision Steel Structure

2014 ◽  
Vol 1065-1069 ◽  
pp. 2251-2254
Author(s):  
Fang Ru Gui
Keyword(s):  
High Precision ◽  
Steel Structure ◽  
Measurement Technology ◽  
Technical Problems ◽  
Total Station ◽  
Calibration Measurement ◽  
Spatial Measurement ◽  
Structure Measurement

The analysis of the difficulties of structure measurement of a stadium and the application of total station instrument spatial measurement technology specifically solve the control and measurement of the steel structure installation, location survey of the pre component installation, and the technical problems in the process of calibration measurement, which has ensured that the accuracy of the entire steel structure construction.

High-precision acoustic modeling with second-order staggered difference

2017 ◽  
Vol 10 (21) ◽  
Author(s):  
Zengli Du ◽  
Jianjun Liu ◽  
Jinping Liu ◽  
Feng Xu ◽  
Yongzhang Li
Keyword(s):  
High Precision ◽  
Second Order ◽  
Acoustic Modeling

The Analysis and Design of a Large Stroke with High-Precision Polarized Laser Interferometer System

2016 ◽  
Vol 679 ◽  
pp. 129-134
Author(s):  
Wan Duo Wu ◽  
Qiang Xian Huang ◽  
Chao Qun Wang ◽  
Ting Ting Wu ◽  
Hong Xie
Keyword(s):  
High Precision ◽  
Measurement Accuracy ◽  
Laser Interferometer ◽  
Laser Interferometry ◽  
Phase Shifting ◽  
Single Frequency ◽  
Rejection Method ◽  
The Common ◽  
Frequency Laser ◽  
Polarization Phase

The technique utilizing single-frequency laser interferometry has very high measurement accuracy, but it has rigorous requirements for optical design which is affected by many factors. In order to achieve single-frequency laser interferometry with large stroke and high precision, the integral layout, the polarization phase shifting technique and the common mode rejection method are adopted to design the length interferometry system. This paper analyzes factors and design requirements which affect measurement accuracy with large stroke. Based on polarization phase shifting technique, the system employs the four-beam-signal detection technique and the common mode rejection method, to make a differential processing of four mutually orthogonal signals. Thus, the influences of zero-drift of intensity and environmental change on system are reduced. Combined with a 200 phase subdivision, the system achieves the resolution with 0.8 nm. Under the VC++ environment, the displacement measurement results are compensated and corrected according to the environmental parameters. Compared with the Renishaw XL-80 laser interferometer, the system has better stability in short term. In the measuring range of 60 mm, the effectiveness of the system is verified.

scholarly journals An Improved Step-Type Liquid Level Sensing System for Bridge Structural Dynamic Deflection Monitoring

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2155 ◽  
Author(s):  
Xijun Ye ◽  
Zhuo Sun ◽  
Xu Cai ◽  
Liu Mei
Keyword(s):  
Measurement Error ◽  
Turbulent Flow ◽  
Measurement Accuracy ◽  
Fluid Velocity ◽  
Step Height ◽  
Liquid Level ◽  
Measurement Point ◽  
Structural Dynamic ◽  
Sensing System ◽  
Step Type

Real-time and accurate monitoring of dynamic deflection is of great significance for health monitoring and condition assessment of bridge structures. This paper proposes an improved step-type liquid level sensing system (LLSS) for dynamic deflection monitoring. Layout of straight-line-type pipeline is replaced by step-type pipeline in this improved deflection monitoring system, which can remove the interference of the inclination angle on the measurement accuracy and is applicable for dynamic deflection monitoring. Fluid dynamics are first analyzed to demonstrate that measurement accuracy is interfered with by the fluid velocity induced by structural vibration, and ANSYS-FLOTRAN is applied for analyzing the influence range caused by the turbulent flow. Finally, a step-type LLSS model is designed and experimented with to verify the influence of the three key parameters (initial displacement excitation, step height, and distance from the measurement point to the elbow) on the measurement accuracy, and the reasonable placement scheme for the measurement point is determined. The results show that the measurement accuracy mainly depends on the turbulent flow caused by step height. The measurement error gets smaller after about 1.0 m distance from the elbow. To ensure that the measurement error is less than 6%, the distance between the measurement point and the elbow should be larger than 1.0 m.

scholarly journals Experimental Comparison of Outdoor Baseline Measurements by Different Methods

2019 ◽  
Vol 131 ◽  
pp. 01057
Author(s):  
Youyi Gu ◽  
Li Wang ◽  
Fengzhuo Xiang ◽  
Wen Ouyang ◽  
Lixing Jiang
Keyword(s):  
Direct Measurement ◽  
High Precision ◽  
Optical Measurement ◽  
Experimental Results ◽  
Experimental Comparison ◽  
Total Station ◽  
Length Standard ◽  
Gnss Receivers ◽  
Surveying And Mapping

Outdoor baseline is the special length standard in the field of surveying and mapping, it can be used to verify the addition and multiplication constants of the total station and other photoelectric rangefinders. In order to ensure the authenticity, accuracy and reliability of verification results, conducting outdoor baseline traceability periodically is essential. At present, direct measurement by 24m invar tape or high precision electro-optical measurement is mainly used to achieve the traceability of outdoor baseline in China. Based on Shenyang baseline field, high precision rangefinder μ-base, 24m invar tape and high precision GNSS receivers are used for comparison experiments, and the experimental results are analyzed.

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