Google Earth引擎对图像集合的简化
Google Earth引擎对图像集合的简化
提问于 2020-09-08 07:10:35
我正在使用CHIRPS数据集(日降水量)来得出特定时间范围内的平均、中值、最小和最大降水量。然后，我想提取包含在点shapefile中的特定位置的值，并将结果保存在表中。脚本似乎可以工作，但输出表中4个变量的值只有零(0)。请参阅下面的脚本
var lng = 65.64;
var lat = 34.35;
var point = ee.Geometry.Point(lat, lng);
//var aoi = point.buffer(100000); // Create an area (1km buffer around point)
var country = ee.FeatureCollection('USDOS/LSIB_SIMPLE/2017')
.filter(ee.Filter.eq('country_co', 'AF'));
var aoi = country;
Map.setCenter(lng, lat, 5); // Center the map on this location, zoom level 10
var start = '2018-02-15'; // initial date of the image collection
var end = '2018-07-15'; //final date of the image collection
var p1 = ee.Geometry.Point([69.78086, 34.65411])
var p2 = ee.Geometry.Point([61.82234, 30.66048])
var table = ee.FeatureCollection(ee.List([ee.Feature(p1),ee.Feature(p2)]))
var AddPrMean = function(image) {
var PrMean = image.reduce(ee.Reducer.mean()).rename('PrMean');
return image.addBands(PrMean);
};
var AddPrMedian = function(image) {
var PrMedian = image.reduce(ee.Reducer.median()).rename('PrMedian');
return image.addBands(PrMedian);
};
var AddPrMin = function(image) {
var PrMin = image.reduce(ee.Reducer.min()).rename('PrMin');
return image.addBands(PrMin);
};
var AddPrMax = function(image) {
var PrMax = image.reduce(ee.Reducer.max()).rename('PrMax');
return image.addBands(PrMax);
};
var dataset = ee.ImageCollection('UCSB-CHG/CHIRPS/DAILY')
.filterDate(start, end)
.filterBounds(aoi)
.map(AddPrMean)
.map(AddPrMedian)
.map(AddPrMin)
.map(AddPrMax);
var composites = dataset.select(['PrMean','PrMedian','PrMin','PrMax']).first();
var YieldLocations = ee.FeatureCollection(table);
var YPrec = composites.reduceRegions(YieldLocations, ee.Reducer.max(), 1);
print(YPrec); ``` 回答 1
Stack Overflow用户
发布于 2020-09-08 09:22:56
我找到了一个似乎有效的解决方案，然而，中位数总是给出0作为结果。
var lat = 34.35;
var point = ee.Geometry.Point(lat, lng);
//var aoi = point.buffer(100000); // Create an area (1km buffer around point)
var country = ee.FeatureCollection('USDOS/LSIB_SIMPLE/2017')
.filter(ee.Filter.eq('country_co', 'AF'));
var aoi = country;
Map.setCenter(lng, lat, 5); // Center the map on this location, zoom level 10
var start = '2018-02-15'; // initial date of the image collection
var end = '2018-07-15'; //final date of the image collection
var p1 = ee.Geometry.Point([69.78086, 34.65411])
var p2 = ee.Geometry.Point([61.82234, 30.66048])
var table = ee.FeatureCollection(ee.List([ee.Feature(p1),ee.Feature(p2)]))
var dataset = ee.ImageCollection('UCSB-CHG/CHIRPS/DAILY')
.filterDate(start, end)
.filterBounds(aoi);
var PrMean = dataset.mean().rename('PrMean');
var PrMedian = dataset.median().rename('PrMedian');
var PrMin = dataset.min().rename('PrMin');
var PrMax = dataset.max().rename('PrMax');
var composites = PrMean
.addBands(PrMedian)
.addBands(PrMin)
.addBands(PrMax);
var YieldLocations = ee.FeatureCollection(table);
var YPrec = composites.reduceRegions(YieldLocations, ee.Reducer.max(), 1);
print(YPrec);```页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/63788802
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