Google Earth Engine——使用可见光红外成像辐射仪套件（VIIRS）日/夜波段（DNB）的夜间数据的月平均辐射度合成图像。

Monthly average radiance composite images using nighttime data from the Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB).

As these data are composited monthly, there are many areas of the globe where it is impossible to get good quality data coverage for that month. This can be due to cloud cover, especially in the tropical regions, or due to solar illumination, as happens toward the poles in their respective summer months. Therefore it is recommended that users of these data utilize the 'cf_cvg' band and not assume a value of zero in the average radiance image means that no lights were observed.

Cloud cover is determined using the VIIRS Cloud Mask product (VCM). In addition, data near the edges of the swath are not included in the composites (aggregation zones 29-32). Version 1 has NOT been filtered to screen out lights from aurora, fires, boats, and other temporal lights. This separation is under development and will be included in a later version of this time series. Also in development is a method to separate lights from background (non-light) values.

Prior to averaging, the DNB data is filtered to exclude data impacted by stray light, lightning, lunar illumination, and cloud-cover.

使用可见光红外成像辐射仪套件（VIIRS）日/夜波段（DNB）的夜间数据的月平均辐射度合成图像。

由于这些数据是按月合成的，全球有许多地区不可能获得该月的高质量数据覆盖。这可能是由于云层的原因，特别是在热带地区，或者是由于太阳光照的原因，如在其各自的夏季月份发生在两极的情况。因此，建议这些数据的用户利用 "cf_cvg "波段，不要认为平均辐射度图像中的数值为零意味着没有观察到灯光。

云层是使用VIIRS的云层掩码产品（VCM）确定的。此外，靠近扫描区边缘的数据不包括在合成物中（聚合区29-32）。第1版还没有过滤掉极光、火灾、船只和其他时间性的灯光。这种分离正在开发中，将包括在这个时间序列的后期版本中。正在开发的还有一种方法，将灯光与背景（非灯光）值分开。

在平均化之前，DNB数据被过滤，以排除受杂散光、闪电、月球光照和云层影响的数据。

数据使用：

Colorado School of Mines data, information, and products, regardless of the method of delivery, are not subject to copyright and carry no restrictions on their subsequent use by the public. Once obtained, they may be put to any lawful use. The forgoing data is in the public domain and is being provided without restriction on use and distribution.科罗拉多矿业大学的数据、信息和产品，无论其交付方式如何，都不受版权保护，对公众的后续使用也没有限制。一旦获得，它们可以被用于任何合法的用途。上述数据属于公共领域，在使用和分发方面不受限制。

Resolution

463.83 meters

Bands Table

* = Values are estimated

代码：

var dataset = ee.ImageCollection('NOAA/VIIRS/DNB/MONTHLY_V1/VCMCFG')
                  .filter(ee.Filter.date('2017-05-01', '2017-05-31'));
var nighttime = dataset.select('avg_rad');
var nighttimeVis = {min: 0.0, max: 60.0};
Map.setCenter(-77.1056, 38.8904, 8);
Map.addLayer(nighttime, nighttimeVis, 'Nighttime');