子午线收敛角计算公式及计算精度分析  

Calculation of Formula of Meridian Constringent Angle and Its Precision Analysis

作　　者：邬熙娟[1] 江国焰[1] 高俊强[1] 

机构地区：[1]南京工业大学土木工程学院,江苏南京210009

出　　处：《现代测绘》2005年第6期22-25,共4页Modern Surveying and Mapping

摘　　要：采用赫里斯托夫给出的展开至七次项的公式来近似地计算子午收敛角的真值,分析了随纬度、经差的变化规律;并对近似公式r=sinB·l计算子午收敛角与其真值之间的较差在经差0．5°-3．5°、纬度5°-85°范围进行详细分析,给出了在经差l=3．5°时较差拟合公式。得到如下结论:1)在同一平行圈上(B=常数),经差l愈大, 较差也愈大;2)在同一子午线上(L=常数),点位处在中纬度(25°-55°)时,较差较大;3)在中低纬度(B=5°- 80°),l=3．5°时,公式(4)的计算精度只能达到0．1";l=2．5°时,计算精度达到0．1"-0．01";l=1．5°时,计算精度达到0．01";l=0．5°时,计算精度达到0．001"-0．0001"。The true value of meridian constringent angle is calculated approximately using formula given by Hristov, and the change rule is analyzed with longitude ＆ latitude It is analyzed that the difference of the true value and approximate value calculated by r=sinB·1 when longitude is between 0.5°and 3.5°, also latitude is between 5°and 85°. Residual formula when longitude interval is 3.5°is obtained. It can be concluded as follows： First, at the same parallels of latitude, the bigger 1 is, the larger the difference is. Second, at the same meridian （L is constant）, when points lay in middle latitude （between 25°and 55°）, the difference is greater. Third, when the 1 value is 3.5°, calculation precision of formula can only reach 0.1＂, when 1 is 2.5＂, it can reach 0.1＂～0.01＂; when 1 is 1.5°, it can reach 0.01＂～0.001＂, when 1 is 0.5°, it can reach 0.001＂～0.0001＂.

关 键 词：子午收敛角 经差 投影带 坐标方位角 

分 类 号：P226.3[天文地球—大地测量学与测量工程]