/**
* @File : cal_wci
* @Time : 2020/12/14
* @Author : Tianjg
* @Version : 1.0
* @Contact : tianjingguo@piesat.cn
* @License : (C)Copyright 航天宏圖信息技術股份有限公司
* @Desc : 計算WCI
*/
var visParamWCI = {
min: 0.3,
max: 1,
opacity: 1,
palette: 'FFFFFF, CE7E45, DF923D, F1B555, FCD163, 99B718, '+
'74A901, 66A000, 529400,3E8601, 207401, 056201, 004C00,'+
'023B01, 012E01, 011D01, 011301'
};
var image = pie.Image("user/9931/bj_water/GF1");
//使用expression表達式計算WCI
var wci = image.expression("((B2-B1)/(555-485))/((B2-B3)/(660-555))", {
B1: image.select("B1"),
B2: image.select("B2"),
B3: image.select("B3")
});
Map.addLayer(wci, visParamWCI, "WCI");
Map.setCenter(116.618278928, 39.785893498700005, 12);