问题1：什么是遥感？

Remote sensing involves the use of instruments or sensors to "capture" the spectral and spatial relations of objects and materials observable at a distance - typically from above them. Or, said another way: Remote sensing is the process of acquiring data/information about objects/substances not in direct contact with the sensor, by gathering its inputs using electromagnetic radiation, acoustical waves, or force fields that emanate from the targets of interest. An aerial photograph is a common example of a remotely sensed (by camera and film, or now digital) product. There are probably hundreds of applications - these are typical: 1) determining the status of a growing crop; 2) defining urban patterns; 3) delineating the extent of flooding; 4) recognizing rock types; 5) pinpointing areas of deforestation.

答案：遥感涵盖了使用传感器或其他设备来“捕捉”远处（主要是从上至下）物体之间的光谱和空间关系。/遥感是不直接与传感器有接触，通过搜集物体的电磁辐射、音波或重力场等指标，而能获取物体的数据和信息。航片就是一个很好的例子，遥感技术的应用十分广泛，典型的应用领域包括：1了解作物生长状况、2描述城市聚落形态、3划分洪灾的影响范围、4确定岩石类型、5界定毁林区域等。