斜轴高斯投影在跨带物探长剖面测量中的应用

在高精度物探重力测量中,需要提供高精度的平面位置和高程。在物探长剖面测量中,对东西跨度较大的线路进行控制测量时,高斯-克吕格投影分带和高程引起的投影变形较大,不能满足长距离重力测量对精度的要求。基于高斯-克吕格投影的基本理论,采用斜轴变形椭球高斯投影方法,结合最小二乘法、坐标转换理论及椭球变换,将原始椭球构建斜轴变形椭球,可以减小高斯投影横坐标和高程投影变形的影响,避免高斯投影分带过多对应用的影响。以漠河—呼和浩特物探长剖面测地数据为例,利用GPS快速静态测量获得平面和高程位置,测点距离约1km,通过斜轴高斯投影进行投影,最大平面精度为67.87mm/km,最大高程精度为53.039mm/km,最大投影综合变形的中误差为88.51 mm/km,大大减小了投影变形,提高了地图投影精度。因此,该投影在跨度物探长剖面测量中的应用具有一定优势。

Application of Oblique Axis Gauss Projection in Geophysical Prospecting Long-Distance Profile Measurement

In high precision geophysical prospecting gravimetry,high accurate plane position and elevation are needed.The projection distortion caused by Gauss-Kruger projection zoning and elevation is too big to meet the precision requirement for control survey in long distance profile of geophysical prospecting.The abscissa projection distortion and elevation influence of Gauss projection can be reduced by the method of oblique axial deformation of the ellipsoid Gauss projection with least squares method,coordinating with the theory of ellipsoid transformation and the theory of Gauss-Kruger.Taking the long-distance profile of Mohe-Hohhot as an example,we obtained the position of plane and elevation using GPS fast static measurement.The distance between measuring points is 1 km in this example.The accuracy obtained by this method is high.The maximum plane precision is 67.87 mm / km,and the maximum height accuracy is 53.039 mm / km.It can be concluded that our method has an advantage in problem solving in geophysical prospecting of long-distance profiles.