不同变形性质正轴圆柱投影和正轴圆锥投影间的直接变换

为避免不同变形性质正轴圆柱投影和正轴圆锥投影间传统间接变换繁琐的计算过程,利用子午线弧长、等量纬度和等面积纬度函数间变换的直接展开式,建立了相应投影坐标间的直接变换模型,无需计算大地纬度即可完成变换。本文导出公式均为含参考椭球第一偏心率的符号形式,可解决两类投影在不同参考椭球下的变换问题。算例分析表明与传统间接变换模型相比,本文建立的直接变换模型提高了计算效率和计算精度,可供实际使用。

The Direct Transformations between Normal Cylindrical and Conic Projections with Different Distortion Properties

In order to avoid the fussy processes of traditional indirect transformations between normal cylindrical and normal conic projections with different distortion properties,the direct transformation models between the corresponding projection coordinates were established using the direct expansions of transformations between meridian arc,isometric latitude and authalic latitude function.The formulas are symbolical expressions which include the first eccentricity of the referenced ellipsoid and could solve the transformation problems when different reference ellipsoids are used.Numerical examples show that the direct transformation modes have improved the computation efficiency and accuracy compared to the traditional indirect transformation ones,and they could satisfy practical use.