idl环境下运行，计算两幅图像的交叉相关系数，用于变化检测方面的研究-idl environment to run the calculation two images of cross-correlation coefficient for change detection studies

时间序列的NPP与气温降水的相关分析，可以更改文件路径，做其他因子之间的相关分析-NPP time series correlation analysis of precipitation and temperature, you can change the file path, making the correlation between the analysis of other factors