【摘要】 解析法测定天文方位角,是作者近年提出的一种新理论、新方法。这种方法的实质是:假设在北极星周日视运动圈附近存在着一个以北天极为中心、以测站子午圈为纵轴、以a,b为长短半径的拟合椭圆;连续观测北极星的天顶距（z_i）和从地面目标起算的水平方向（y_i）,并将（z_i,y_i）一对观测值归算到拟合椭圆上,成为椭圆上的观测值（x_i,y_i）;给定椭圆中心初始近似值（x₀,y₀）,建立椭圆条件方程组,依最小二乘原理平差,迭代（x₀,y₀）,得出北天极方向平差值（y₀）,进而得到地面目标的天文方位角a_n（a_n=360°-（?）₀）。这种方法从理论上使天文观测与时间脱离关系,原理直观浅显,操作简便易行,是地质勘查中作独立平面测量控制网定向的一种理想而有效的方法。更多还原

【Abstract】 The analytic method for determining astronomical azimuths is a new means, put forward recently by the writer, and a new theory as well. Its essence is as follows. Suppose that near the diurnal apparent motion circle of the Polaris exist a fitting ellipse, with the north celestial pole as its centre, the observer’s meridian as its ordinate axis, a and b as its major radius and minor radius separately. Measure the zenith distances ( zi ) and the horizontal directions ( yi ) of the Polaris continually, the horizontal direction of a target on the earth used as the starting horizontal direction. Then transform the two groups of measurements ( zi,yi ) into the values ( xi, yi ) which are regarded as the observed values to the ellipse. Initialize the centre of the ellipse ( xo,y0 ). Then form the conditional equations of the ellipse and solve the conditional equations by the method of least squares. After several iterations the astronomical azimuth of the target on the earth is obtained (an = 360-y0). Theoretically the astronomical measurement bears no relation to the time by this method. The operation can be executed easily. This is an ideal and effectual method for directing isolated horizontal control networks in the geological surveying.更多还原