terrain spectral reflectivity

例句：

1. 1.The mountain terrain is very challenging to navigate.
   山区的地形非常难以导航。
2. 2. The geological survey team carefully examined the terrain for signs of mineral deposits.
   地质调查队仔细检查了地形，寻找矿物矿藏的迹象。
3. 3.The engineer used a GPS device to map out the terrain before building the bridge.
   工程师使用GPS设备来绘制桥梁建设前的地形图。