Research on positioning method of digital zenith camera under rough leveling state

Yang Shang; Zhou Zhaofa; Liu Xianyi; Zhang Hui

doi:10.3788/IRLA201847.0817007

A positioning method of digital zenith camera was proposed to solve the problem that the traditional positioning method required precise leveling of the instrument, the data fitting model parameter was inaccurate and the positioning iterative process was complicated. The calculation formula of CCD image coordinates in the horizontal state was derived. CCD image coordinates of the horizontal state were obtained by using the CCD image coordinates under rough leveling and the output value of the inclinometer, and the star tangent plane coordinates under rough leveling were analyzed, the analysis results showed that the star tangent plane coordinates which needn't be correct could be used to establish data fitting model. The parameters of the data fitting model were calculated by the robust estimation, which restrained the influence of rough error on the parameters and improved the accuracy of the data fitting model. In the end, positioning iterative process was optimized by solving the simultaneous equations of data fitting model to gain the CCD image coordinates of rotating axis, eliminating the inverse transformation of data fitting model and taking the average of the plane coordinates, which improved the efficiency and ensured the positioning accuracy. The experimental results showed that the positioning precision of positioning method under rough leveling is basically the same as the positioning method under fine leveling state. The accuracy of the positioning longitude under rough leveling is 0.306, the accuracy of the latitude is 0.292. Positioning accuracy satisfies the positioning requirement of digital zenith camera.

Research on positioning method of digital zenith camera under rough leveling state

1. State Key Discipline Laboratory of Armament Launch Theory and Technology,Rocket Force University of Engineering,Xi'an 710025,China

Received Date: 2018-03-05

Rev Recd Date: 2018-04-03

Publish Date: 2018-08-25

Key words:

Abstract: A positioning method of digital zenith camera was proposed to solve the problem that the traditional positioning method required precise leveling of the instrument, the data fitting model parameter was inaccurate and the positioning iterative process was complicated. The calculation formula of CCD image coordinates in the horizontal state was derived. CCD image coordinates of the horizontal state were obtained by using the CCD image coordinates under rough leveling and the output value of the inclinometer, and the star tangent plane coordinates under rough leveling were analyzed, the analysis results showed that the star tangent plane coordinates which needn't be correct could be used to establish data fitting model. The parameters of the data fitting model were calculated by the robust estimation, which restrained the influence of rough error on the parameters and improved the accuracy of the data fitting model. In the end, positioning iterative process was optimized by solving the simultaneous equations of data fitting model to gain the CCD image coordinates of rotating axis, eliminating the inverse transformation of data fitting model and taking the average of the plane coordinates, which improved the efficiency and ensured the positioning accuracy. The experimental results showed that the positioning precision of positioning method under rough leveling is basically the same as the positioning method under fine leveling state. The accuracy of the positioning longitude under rough leveling is 0.306, the accuracy of the latitude is 0.292. Positioning accuracy satisfies the positioning requirement of digital zenith camera.

HTML

Reference (17)

[1]	Hirt C, Seeber G. Accuracy analysis of vertical deflection data observed with the Hannover digital zenith camera system TZK2-D[J]. Journal of Geodesy, 2008, 82(6):347-356.
[2]	Hirt C, Brki B,Guillaume S,et al. Digital zenith cameras-state-of-the-art astrogeodetic technology for Australian Geodesy[C]//FIG Congress-Remote Sensing and Optical Techniques I, 2010:1-16.
[3]	Hirt C, Reese B, Enslin H. On the accuracy of vertical deflection measurement using the high-precision digital zenith camera system TZK2-D[C]//Gravity, Geoid and Space Mission, 2005:197-201.
[4]	Guo Min, Zhang Hongying. Application of CCD digital photography in astronomical positioning measurement[J]. Geomatics Technology and Equipment, 2005, 1(7):28-29. (in Chinese)
[5]	Wang Bo, Tian Lili, Wang Zheng, et al. The image and data processing in digital zenith camera[J]. Chin Sci Bull, 2014, 59(12):1100-1107.
[6]	Zhang Xihui, Zhou Zhaofa, Liu Xianyi, et al. Analysis of the fast positioning method of digital zenith camera in tilt state[J]. Infrared and Laser Engineering, 2018, 47(2):0217002. (in Chinese)
[7]	Liu Xianyi, Zhou Zhaofa, Zhang Zhili, et al. Research on the transformation of coordinates astronomical fixation[J].Electronics Optics Control, 2016, 23(1):11-14. (in Chinese)
[8]	Qin Yongyaun. Inertial Navigation[M]. Beijing:Science Press, 2014:244-252. (in Chinese)
[9]	Zhou Zhaofa, Liu Xianyi, Zhang Zhili, et al. Research on two-axis tilt sensor based on digital zenith camera[J]. Acta Photonic Sinica, 2015, 44(8):08120021. (in Chinese)
[10]	Yanc Y, He H, Ru C. Adaptively robust filtering for kinematic geodetic positioning[J]. Journal of Ueodesy, 2001, 76(2):109-116.
[11]	Yang Y, Song I, Xu T. Robust estimator for correlated observations based on bifactor equivalent weights[J]. Journal of Geodesy, 2002, 76(6):353-358.
[12]	Yang Yuanxi. Equivalent weight principle:parameter adjustment model robust least squares solution[J]. Bulletin of Surveying and Mapping, 1994, 42(6):33-35. (in Chinese)
[13]	Yang Yuanxi. Robust estimation and its influence function of surveying adjustment mode[J]. Journal of the Institute of Surveying and Mapping, 1994, 11(2):77-82. (in Chinese)
[14]	Zhang Xinshuai, Zhou Zhaofa, Huang Xianxiang. Improved positioning method for digital zenith camera[J]. Infrared and Laser Engineering, 2015, 44(4):1254-1259. (in Chinese)
[15]	Zhang Zhili, Liu Xianyi, Zhou Zhaofa, et al. Infiuence of turntable error on axis error in digital zenith camera[J].Optics and Precision Engineering, 2015, 23(11):3090-3096. (in Chinese)
[16]	Liu Xianyi, Zhou Zhaofa, Zhang Zhili, et al. The application of spherical triangle method in digital zenith camera[J]. Journal of Geodesy and Geodynamics, 2015, 35(4):726-728.
[17]	Tian Lili, Guo Jinyun, Han Yanben, et al. Digital zenith telescope prototype of china[J]. Chin Sci Bull, 2014, 59(12):1094-1099.

Research on positioning method of digital zenith camera under rough leveling state

doi: 10.3788/IRLA201847.0817007

Abstract

References

Proportional views

通讯作者: 陈斌, bchen63@163.com

Article Metrics

Related

Proportional views