Researchers have used the brightness of lights in nighttime images to estimate an area's economic activity.

研究人员利用夜间图像中的灯光亮度来估计一个地区的经济活动。

Then there's Zizhuyuan Park, also near the West Third Ring.  If I remember correctly, it has lots of waterways and pavilions, even an activity area for kids.

还有紫竹院公园，也在西三环附近。如果我没记错的话，那里有很多水道和亭子，甚至还有儿童活动区。