数字天顶仪中倾角仪参数的标定

Calibration of inclinometer parameters in digital zenith camera

针对运用数字天顶仪进行天文定位时旋转轴与垂直轴之间存在的轴系偏差,提出了高精度天顶仪倾角补偿方法。从数字天顶仪倾角补偿原理出发,引入了倾角仪双轴尺度系数、双轴交角等参数对倾角仪的输出值进行修正,然后提出了一种双轴倾角仪参数的标定方法。分析了旋转角度对于参数标定的影响,运用实验数据对标定方法进行了论证。结果显示:旋转角度会直接影响CCD图像传感器安装角度的标定值。另外,倾角仪参数的引入提高了数字天顶仪的定位精度,当旋转角度的误差值在2°以内时,标定参数的误差对定位结果的影响非常小。

To compensate the axis errors between rotation axis and vertical axis when a digital zenith camera was used in celestial positioning,a incline angle compensation method for the digital zenith camera was proposed.On the principle of incline angle compensation,the scale coefficients and the cross angle of two axes were taken into account to modify the inclinometer values.Then,a calibration method was proposed for the parameters of the two-axis inclinometer.The influence of rotation angle on calibration parameters was analyzed,and some experimental data were used to verify the calibration method.The result demonstrates that the rotation angle directly affects the calibration of CCD installation angle.Moreover,the introduction of inclinometer parameters improves the positioning accuracy.If the error of rotation angle is below 2°,the influence caused by inclinometer parameters can be ignored.