ABSTRACT Data from the Geostationary Operational Environmental Satellite 16 (GOES-16) are used to study the number of clear nights over Colombia in order to identify potential sites for astronomical observations. First, we compare data from the Advanced Baseline Imager (ABI) with in-situ observations from an all-sky camera in order to validate the cloud cover information from the ABI retrievals. Then, we extend the analysis of the GOES-16 cloud cover fields to quantify the number of hours with low values of cloud cover for each pixel and each day of 2018 for a region that includes Colombia. A clear night is defined as one with five or more consecutive hours with a low fraction of cloud cover. We select the potential sites as those with more than 80 clear nights and with an altitude higher than 2000 m above sea level (m.a.s.l.). Our analyses showed that nine sites fulfil these conditions: five are in Colombia, three are in Ecuador and one in Venezuela. From our sample, eight out of the nine sites are in the Andes Mountains. The results suggest that the most suitable site for astronomical observations in Colombia is located near to Laguna de la Cocha, in the department of Nariño, with 135 clear nights in 2018 (about 37% of the year), followed by a site near to Lago de Tota, with 117 clear nights (about 32% of the year), located near the centre of the country. Exploration of regions outside Colombia showed that the Ecuadorian Andes has locations with approximately 48% of clear nights during the studied year. We conclude that the use of GOES images to measure the number of clear nights in order to select potential astronomical site locations has a great potential.

中文翻译：

---

使用 GOES-16 图像估计晴空夜的数量：搜索哥伦比亚的天文站点

摘要 地球静止运行环境卫星 16 (GOES-16) 的数据用于研究哥伦比亚上空晴朗夜晚的数量，以确定天文观测的潜在地点。首先，我们将来自高级基线成像仪 (ABI) 的数据与来自全天相机的原位观测数据进行比较，以验证来自 ABI 检索的云覆盖信息。然后，我们扩展了对 GOES-16 云量场的分析，以量化每个像素和 2018 年每一天的云量值较低的小时数，其中包括哥伦比亚在内。晴朗的夜晚被定义为连续五个或更多小时且云层覆盖率较低的夜晚。我们选择的潜在地点是那些拥有 80 个以上晴朗夜晚和海拔 2000 m 以上（masl）的地点。我们的分析表明，九个地点满足这些条件：五个在哥伦比亚，三个在厄瓜多尔，一个在委内瑞拉。从我们的样本中，九个地点中有八个位于安第斯山脉。结果表明，哥伦比亚最适合进行天文观测的地点位于纳里尼奥省 Laguna de la Cocha 附近，2018 年有 135 个晴朗的夜晚（约占全年的 37%），其次是靠近 Lago 的地点de Tota 位于该国中部附近，拥有 117 个晴朗的夜晚（约占全年的 32%）。对哥伦比亚以外地区的探索表明，在研究的一年中，厄瓜多尔安第斯山脉有大约 48% 的夜晚晴朗。我们得出的结论是，使用 GOES 图像来测量晴朗夜晚的数量以选择潜在的天文站点具有很大的潜力。