Geospatial interpolation 差值

空间差值法的用途

1. kernel density estimation (Heatmap)

2. IDW Interpolation

2.1 计算公式

Inverse Distance Weighting (IDW) Interpolation

\[x_j = \frac{\sum_{i=1}^N x_i \cdot \frac{1}{d_i^p}}{\sum_{i=1}^N \frac{1}{d_i^p}} \]

where:

• \(p\) is a parameter, represents the power of distance

• \(i=1, \cdots, N\) is the index of the given point

• \(d_i\) is the distance from point \(i\) to the point \(j\)

• \(x_i\) is the attribute of point \(i\)

2.2 应用

将点（point）数据转化成等高线数据（contour），如：处理气象数（站）据

• 或者可以使用 Qgis 的 Contour plugin 插件

References

Kernel

• QGIS Heatmap Using Kernel Density Estimation Explained, site

• Kernel (statistics), site

IDW Interpolation

• "11. Spatial Analysis (Interpolation)" in A Gentle Introduction to GIS, site

• "27.1.5.2. IDW Interpolation" in QGIS User Guide, site

• Inverse Distance Weighting (IDW) Interpolation, GIS Geography, site

• Interpolating Point Data (QGIS3), site

• 基于 QGIS 的气象数据可视化（一）, CSDN博客, site