ICE去云算法的示例代码 我们开源的仓库旨在说明论文Daily 250m MODIS NDVI Timeseries Reconstruction using Iterative Continuum Extraction and Savitzky-Golay Filter中所涉及的迭代包络线去云算法原理。目前仓库包含两个节点，第一个节点包括ICE_SG算法的原理脚本；第二个节点演示模拟实验的过程。
需要说明的是，我们采用的实验数据为MOD09GQ和MOD09GA，数据的预处理（重投影、裁剪、镶嵌、波段合成等）以及样本的选取等其他操作可在MRT、ENVI、ArcGIS等软件完成，相关代码可从其他开源渠道获得，我们在此感谢相关开源代码的作者对我们完成试验提供的帮助。并且我们提出的算法对高时间分辨率NDVI时间序列是普遍有效的，使用者可以根据需要设计自己的数据处理方式。
我们提供了示例文件以辅助理解代码，其中2016_Heilongjiang_dadou_raw_000.txt为时间序列NDVI数据，由MOD09GQ数据计算获得；simulate_true.txt是模拟实验使用的平滑曲线，由matlab timesat获得; weather.txt为simulate_weather_distribution_for_git读取MOD09GQ质量波段和MOD09GA云波段获取的天气分布
This open source repository aims to illustrate the NDVI timeseries reconstruction method in the paper Daily 250m MODIS NDVI Timeseries Reconstruction using Iterative Continuum Extraction and Savitzky-Golay Filter. The first branch includes the principle script of ICE_SG algorithm; the second branch demonstrates the process of simulation experiment.
It should be pointed out that we used MOD09GQ and MOD09GA as experimental data, and the data preprocessing such as reprojection, mosaic and layer stacking can be conducted on software like MRT, ENVI and ArcGIS. The related code of the data processing can be obtained from other open source channels. We appreciate the help from author of the open source program, the excellent codes they shared did a lot of good for us to complete our experiments. What’s more, the proposed algorithm is generally effective for high temporal resolution NDVI timeseries of all kinds of data resources, and users can design their own data processing methods according to their needs.
We provide sample files to help understand the codes. Among which the “2016 _heilongjiang_dadou_raw_000.txt” is NDVI timeseries, driven from MOD09GQ data; “Simulate_true.txt” is the simulated true NDVI curve used in the simulation experiment, obtained by Matlab Timesat; “Weather.txt” is weather distribution in the simulated experiment from the MOD09GQ quality band and the MOD09GA cloud band. We used IDL process file “simulate_weather_distribution_for_git” to calculate it.