基于二元样条函数的DEM传递误差模型

根据两点数值微分公式建立了基于二元样条函数的规则格网数字高程模型(DEM)的表面表达模型,得出了基于二元样条函数的传递误差公式。公式表明,二元样条函数的DEM传递误差与双线性多项式的传递误差相同。但由于样条函数的DEM表面建模误差低于线性多项式的DEM表面建模误差,因此,基于样条函数的DEM表面模型具有更高的精度。

Propagation Error of DEM Based on Splines Interpolation

Based on two-point digital differential formula,a model to represent the surface of a grid DEM based on two-element splines interpolation is obtained,and a propagation error formula by the spline is derived.The formula shows that the propagation error from spline is the same as the error from double linear polynomial.But the model error by spline is the smaller the error by double linear polynomial,hence the accuracy based on spline is the better the accuracy based on double linear polynomial.