关于用量距法测定偏角,李振安同志建议将过去的5米法改进为10米法(载于1965年第一期“公路”)。根据我们用量距法测定偏角的体会,从角点起向切线的延长线与另一切线方向各量5米后(见下图),量出的AB之长缩小10倍,即为Q/2的正弦函数值 With regard to the determination of declination by distance gauging, Comrade Li Zhen’an proposed to improve the previous 5-meter method to 10-meter method (contained in the first phase of 1965 “Highway”). According to our understanding of the declination from the distance method, from the corner point to the tangent of the extension line and the other tangential direction of the amount of 5 meters (see below), the amount of the AB reduced by 10 times the length of that is Q / 2 sine function value