/**
                * @File    :   VIIRS_V1
                * @Time    :   2020/12/30
                * @Author  :   piesat
                * @Version :   1.0
                * @Contact :   400-890-0662
                * @License :   (C)Copyright 航天宏图信息技术股份有限公司
                * @Desc    :   加载VIIRS Nighttime Day: Night Band Composites Version 1数据集
                */
               
               //加载中国边界
               var china = pie.FeatureCollection("RESDC/WORLD_COUNTRY_BOUNDARY")
                              .filter(pie.Filter.eq("name", "CHINA"))
                              .first()
                              .geometry();
               //加载2020年1月中国VIIRS数据
               var img = pie.ImageCollection('VIIRS_VCMCFG/NIGHTTIME_LIGHTS')
                            .filterDate("2019-12-01", "2020-01-01")
                            .filterBounds(china)
                            .select("avg_rad")
                            .mosaic().clip(china);
               print(img);
               //设定预览参数
               visParams = {
                   min: 0,
                   max: 60000,
                   palette:['000000','4c3300','664401','7f5501','996601','b27702',
                   'cc8802','e59902','ffad02','ffaf02','ffb102','ffb302','ffb502',
                   'ffb702','ffb902','ffbb02','ffbd02','ffc002','ffc202','ffc402',
                   'ffc602','ffc801','ffca01','ffcc01','ffce01','ffd001','ffd201',
                   'ffd501','ffd701','ffd901','ffdb01','ffdd01','ffdf01','ffe101',
                   'ffe300','ffe500','ffe700','ffea00','ffec00','ffee00','fff000',
                   'fff200','fff400','fff600','fff800','fffa00','fffc00','ffff00']
               };
               //加载显示影像
               Map.centerObject(china, 2);
               Map.addLayer(img, visParams, "VIIRS_V1");