学术交流|航天宏图PIE-Engine遥感云平台在棉花方面所做的工作(5)

27.var nir = img.select("B8");
28.var NDVI = (nir.subtract(red)).divide(nir.add(red)).rename("NDVI");
29.var NDWI = (green.subtract(nir)).divide(green.add(nir)).rename("NDWI");
30.var SPAD = (re3.divide(re2)).multiply(25.34).subtract(28.06).rename("SPAD");
31.
32.//根据敏感特征提取棉花并显示
33.var cot_RGB = img.select(["B4", "B3", "B2"])
34. .updateMask(lc.eq(1).and(nir.gt(4500)).and(NDVI.gt(0.5)));
35.Map.addLayer(cot_RGB,
36.
37.//掩膜获取棉花NDVI
38.var cot = NDVI.updateMask(lc.eq(1).and(nir.gt(4500)).and(NDVI.gt(0.5)));
39.
40.//按不同阈值显示NDVI
41.var cot_NDVI = cot.where(cot.gt(0.50).and(cot.lte(0.75)), 1)
42. .where(cot.gt(0.75).and(cot.lte(0.80)), 2)
43. .where(cot.gt(0.80).and(cot.lte(0.85)), 3)
44. .where(cot.gt(0.85).and(cot.lte(0.90)), 4)
45. .where(cot.gt(0.90).and(cot.lte(1.00)), 5);
46.Map.addLayer(cot_N
47.
48.//计算棉花NDVI最大值、最小值以及均值
49.var NDVI_max = cot.reduceRegion(pie.Reducer.max(), shz, 30).get("NDVI").getInfo();