最小二乘平差在纸海图矢量化过程中的应用

在矢量化纸海图时，由于基准点的采样误差，导致转换参数的误差，最终导致电子海图的空间对象的精度不高。本文应用最小二乘法对基准点的采样误差实施平差，提高转换参数的精度，最终可较大幅度地提高电子海图中空间对象的精度

Application of Least Square Algorithm in Process of Digitizing Nautical Chart

In process of digitizing chart the sampling errors of datum marks will bring about the errors of transformation parameters and eventually cause lower precision of spatial objects of electronic nautical chart(ENC).Least square algorithm is applied to deal with the errors of sampling datum marks for enhancing transformation precision.Then,the precision of ENC spatial objects is greatly improved by about 70 percents. Key words:electronic nautical chart(ENC); nautical chart; digitizing; least square algorithmrovement scheme; rotor one point earthing; time sequence; electronic switchction, bearing of the bar deformation and restraint of concrete cover leads to obvious deterioration of the bond behavior as the corrosion rate of steel bar increases. According to the testing results, the relationship of bond stress and shear slip of corroded steel bar is established.