GEE开发之Modis_NDVI数据分析获取大总结

前言：主要总结一下在GEE上获取Modis_NDVI数据的各种形式，主要包括MYD13Q1、MOD09GA、MOD13Q1、MOD13A1、MOD13A2以及日数据、月数据、年数据的获取和下载。

0. 之前的博客链接

之前总结的Modis_NDVI数据分析的博客链接如下：
《GEE开发之Modis_NDVI的数据分析》
《GEE开发之MODIS_NDVI年均值数据分析》
《GEE开发之MODIS_NDVI一年之中的所有数据获取》

1. MYD13Q1(250米/16天)

//以鹿邑为例子 
var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
//选取影像集以及波段 NDVI
var ndvi = ee.ImageCollection("MODIS/006/MYD13Q1").filterDate('2020-01-01', '2020-12-31').filterBounds(geometry).select("NDVI");
//换算单位
var multiply = function(image){ 
 var img = image.multiply(0.0001);  
 return img.set('system:time_start',image.get('system:time_start'));
};
ndvi = ndvi.map(multiply);
print(ndvi);
//设置调色板并展示影像
var colorizedVis = {min: 0.0,  max: 1.0,  palette: ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901', '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',  '012E01', '011D01', '011301']};
Map.addLayer(ndvi.median().clip(geometry), colorizedVis, 'NDVI');//2020年NDVI的均值

此图是鹿邑县2020年NDVI的均值

2. MOD09GA_006_NDVI(500米/1天)

//以鹿邑为例子 
var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
//选取影像集以及波段 NDVI
var ndvi = ee.ImageCollection("MODIS/MOD09GA_006_NDVI").filterDate('2020-01-01', '2020-12-31').filterBounds(geometry).select("NDVI");
print(ndvi);
//设置调色板并展示影像
var colorizedVis = {min: 0.0,  max: 1.0,  palette: ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901', '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',  '012E01', '011D01', '011301']};
Map.addLayer(ndvi.median().clip(geometry), colorizedVis, 'NDVI');//2020年NDVI的均值

3. MOD13Q1(250米/16天)

//以鹿邑为例子 
var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
//选取影像集以及波段 NDVI
var ndvi = ee.ImageCollection("MODIS/006/MOD13Q1").filterDate('2020-01-01', '2020-12-31').filterBounds(geometry).select("NDVI");
//换算单位
var multiply = function(image){ 
  var img = image.multiply(0.0001);  
  return img.set(image.toDictionary(image.propertyNames()));
};
ndvi = ndvi.map(multiply);
print(ndvi);
//设置调色板并展示影像
var colorizedVis = {min: 0.0,  max: 1.0,  palette: ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901', '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',  '012E01', '011D01', '011301']};
Map.addLayer(ndvi.median().clip(geometry), colorizedVis, 'NDVI');

4. MOD13A1(500米/16天)

//以鹿邑为例子 
var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
//选取影像集以及波段 NDVI
var ndvi = ee.ImageCollection("MODIS/006/MOD13A1").filterDate('2020-01-01', '2020-12-31').filterBounds(geometry).select("NDVI");
//换算单位
var multiply = function(image){ 
  var img = image.multiply(0.0001);  
  return img.set(image.toDictionary(image.propertyNames()));
};
ndvi = ndvi.map(multiply);
print(ndvi);
//设置调色板并展示影像
var colorizedVis = {min: 0.0,  max: 1.0,  palette: ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901', '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',  '012E01', '011D01', '011301']};
Map.addLayer(ndvi.median().clip(geometry), colorizedVis, 'NDVI');

5. MOD13A2(1000米/16天)

//以鹿邑为例子 
var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
//选取影像集以及波段 NDVI
var ndvi = ee.ImageCollection("MODIS/006/MOD13A2").filterDate('2020-01-01', '2020-12-31').filterBounds(geometry).select("NDVI");
//换算单位
var multiply = function(image){ 
  var img = image.multiply(0.0001);  
  return img.set(image.toDictionary(image.propertyNames()));
};
ndvi = ndvi.map(multiply);
print(ndvi);
//设置调色板并展示影像
var colorizedVis = {min: 0.0,  max: 1.0,  palette: ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901', '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',  '012E01', '011D01', '011301']};
Map.addLayer(ndvi.median().clip(geometry), colorizedVis, 'NDVI');//NDVI均值显示

6. 日数据下载(以MYD13Q1为例子)

//以鹿邑为例子 
var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
//选取影像集以及波段 NDVI
var ndvi = ee.ImageCollection("MODIS/006/MYD13Q1").filterDate('2020-01-01', '2020-12-31').select("NDVI");
//换算单位
var multiply = function(image){ 
 var img = image.multiply(0.0001);  
 return img.set('system:time_start',image.get('system:time_start'));
};
ndvi = ndvi.map(multiply);
//设置调色板并展示影像
var colorizedVis = {min: 0.0,  max: 1.0,  palette: ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901', '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',  '012E01', '011D01', '011301']};
print(ndvi);
function exportImageCollection(imgCol) {
  var indexList = imgCol.reduceColumns(ee.Reducer.toList(), ["system:index"]).get("list");
  indexList.evaluate(function(indexs) {
    for (var i=0; i<indexs.length; i++) {
      var image = imgCol.filter(ee.Filter.eq("system:index", indexs[i])).first();
      image = image.clip(geometry);
      Map.addLayer(image, colorizedVis, indexs[i]);//查看具体的遥感影像
      //tif数据下载
      Export.image.toDrive({
        image: image,
        description: 'modis_ndvi_'+indexs[i],
        fileNamePrefix: 'modis_ndvi_'+indexs[i],
        folder: 'Modis',
        region: geometry,
        scale: 250,
        crs: "EPSG:4326",
        maxPixels: 1e13
      });
    }
  });
}
exportImageCollection(ndvi);

7. 月数据下载(以MYD13Q1为例子)

7.1 代码一

//以鹿邑为例子 
var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
//选取影像集以及波段 NDVI
var ndvi = ee.ImageCollection("MODIS/006/MYD13Q1").filterDate('2020-01-01', '2020-12-31').select("NDVI");
//换算单位
var multiply = function(image){ 
 var img = image.multiply(0.0001);  
 return img.set('system:time_start',image.get('system:time_start'));
};
ndvi = ndvi.map(multiply);
//设置调色板并展示影像
var colorizedVis = {min: 0.0,  max: 1.0,  palette: ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901', '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',  '012E01', '011D01', '011301']};

//时间范围
var years = ee.List.sequence(2020, 2020);
var months = ee.List.sequence(1, 12);

//将逐日数据生成月平均数据
var monthlymeanNDVI =  ee.ImageCollection.fromImages(
  years.map(function (y) {
    return months.map(function(m) {
      return ndvi.filter(ee.Filter.calendarRange(y,y, 'year')).filter(ee.Filter.calendarRange(m, m, 'month')).mean().set('year', y).set('month', m).set('system:time_start', ee.Date.fromYMD(y, m, 1));
    });
  }).flatten());

print(monthlymeanNDVI)
function exportImageCollection(imgCol) {
  var indexList = imgCol.reduceColumns(ee.Reducer.toList(), ["system:index"]).get("list");
  indexList.evaluate(function(indexs) {
    for (var i=0; i<indexs.length; i++) {
      var image = imgCol.filter(ee.Filter.eq("system:index", indexs[i])).first();
      image = image.clip(geometry);
      Map.addLayer(image, colorizedVis, indexs[i]);//查看具体的遥感影像
      //tif数据下载
      Export.image.toDrive({
        image: image,
        description: 'modis_ndvi_'+indexs[i],
        fileNamePrefix: 'modis_ndvi_'+indexs[i],
        folder: 'Modis',
        region: geometry,
        scale: 250,
        crs: "EPSG:4326",
        maxPixels: 1e13
      });
    }
  });
}
exportImageCollection(monthlymeanNDVI);

7.2 代码二（简洁）

var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
var NDVI =ee.ImageCollection("MODIS/006/MYD13Q1");
for(var i=2018;i<=2020;i++){
  for(var j=1;j<=12;j++){
    var data_collection = null;
    switch(j){
      case 1:
      case 3:
      case 5:
      case 7:
      case 8:
      case 10:
      case 12:
        data_collection = NDVI.filterDate(i+'-'+j+'-01',i+'-'+j+'-31').select('NDVI');
        break;
      case 4:
      case 6:
      case 9:
      case 11:
        data_collection = NDVI.filterDate(i+'-'+j+'-01',i+'-'+j+'-30').select('NDVI');
        break;
      case 2:
        data_collection = NDVI.filterDate(i+'-'+j+'-01',i+'-'+j+'-28').select('NDVI');
        break;
    }
    // print(data_collection)
    var YR_collection = data_collection.mean().multiply(0.0001).clip(geometry);
    // print(YR_collection)
    Export.image.toDrive({
      image: YR_collection,
      description: i+'-'+j,
      fileNamePrefix: i+'-'+j,
      scale: 250,
      region: geometry,
      maxPixels: 1e13,
      folder: 'Modis'
    })
  }
}

8. 年数据下载(以MYD13Q1为例子)

8.1 代码一

 var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
// 选择数据集并进行波段比例换算
var collection = ee.ImageCollection("MODIS/006/MOD13Q1").filterDate('2000-01-01', '2020-12-31').select("NDVI");
//换算单位
var multiply = function(image){ 
  var img = image.multiply(0.0001);  
  return img.set(image.toDictionary(image.propertyNames()));
};
collection = collection.map(multiply);
//进行年平均值的计算
var years = ee.List.sequence(2000, 2020);
var collectYear = ee.ImageCollection(years
  .map(function(y) {
    var start = ee.Date.fromYMD(y, 1, 1);
    var end = start.advance(12, 'month');
    return collection.filterDate(start, end).reduce(ee.Reducer.mean()).float().set('system:time_start',y).set('year',y);
}));
print(collectYear);

//年均值的时间序列展示
var Yearly_chart = ui.Chart.image.series({
    imageCollection: collectYear.select('NDVI_mean'),
    region: geometry,
    reducer: ee.Reducer.mean(),
    scale: 500,
    xProperty: 'year',
    }).setOptions({
      interpolateNulls: true,
      lineWidth: 2,
      title: 'NDVI Yearly Seires',
      vAxis: {title: 'NDVI'},
      hAxis: {title: 'Date'},
      //trendlines: { 0: {title: 'NDVI_trend',type:'linear', showR2: true,  color:'red', visibleInLegend: true}}
    });
print(Yearly_chart);
var colorizedVis = {min: 0.0,  max: 1.0,  palette: ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718', '74A901', '66A000', '529400', '3E8601', '207401', '056201', '004C00', '023B01',  '012E01', '011D01', '011301']};
function exportImageCollection(imgCol) {
  var indexList = imgCol.reduceColumns(ee.Reducer.toList(), ["system:index"]).get("list");
  indexList.evaluate(function(indexs) {
    for (var i=0; i<indexs.length; i++) {
      var image = imgCol.filter(ee.Filter.eq("system:index", indexs[i])).first();
      image = image.clip(geometry);
      Map.addLayer(image, colorizedVis, indexs[i]);//查看具体的遥感影像
      //tif数据下载
      Export.image.toDrive({
        image: image,
        description: 'modis_ndvi_'+indexs[i],
        fileNamePrefix: 'modis_ndvi_'+indexs[i],
        folder: 'Modis',
        region: geometry,
        scale: 250,
        crs: "EPSG:4326",
        maxPixels: 1e13
      });
    }
  });
}
exportImageCollection(collectYear);

8.2 代码二（简洁）

var geometry = ee.FeatureCollection('users/www1573979951/luyixian');
Map.centerObject(geometry,6);
var NDVI =ee.ImageCollection("MODIS/006/MYD13Q1");

for(var i=2018;i<=2020;i++){
  var data_collection = NDVI.filterDate(i+'-01-01',i+'-12-31').select('NDVI');
  print(data_collection)
  var YR_collection = data_collection.mean().multiply(0.0001).clip(geometry);
  Export.image.toDrive({
    image: YR_collection,
    description: i,
    fileNamePrefix: i,
    scale: 250,
    region: geometry,
    maxPixels: 1e13,
    folder: 'Modis'
  });
}