所谓遥感,就是当我们对遥远的目标不能看到或识别其情况时,借助目标对电磁波的辐射、反射、透射或吸收等现象来识别其情况。例如月亮离我们很远,过去我们不知道它的真实情况,在人登上月球以后,才看到了月球上的真实情况,但在登上月球之前,人们做了很多准备工作,拍了很多照片,对月球有了很多认识,这些认识的来源,主要是靠遥感技术。现在遥感技术已被广泛应用,特别对宇宙太空、地球表面的情况,更需要利用遥感技术来侦查和探索。取得遥感信息所用的电磁波主要是可见光、红外线和微波。因频谱不同,各种遥感器的结构差别很大。对于可见光,所用遥感器主要是光学器件(如照相机)和光电器件(如电视摄象机),其基本原理与常用器件是相同的,只是设计改变,使之更适于远距离应用而 The so-called remote sensing, that is, when we can not see or identify the situation of distant targets, with the target of electromagnetic radiation, reflection, transmission or absorption and other phenomena to identify the situation. For example, the moon is very far away from us. In the past, we did not know the real situation. We did not see the real situation on the moon after we had landed on the moon. But before we got on the moon, people did a lot of preparatory work and took lots of photos , A lot of understanding of the moon, the source of these understandings, mainly by remote sensing technology. Now remote sensing technology has been widely used, especially for the cosmic space, the surface of the earth, but also the need to use remote sensing technology to detect and explore. The electromagnetic waves used to obtain remote sensing information are mainly visible, infrared and microwaves. Due to different spectrum, a variety of remote sensor structure vary greatly. For visible light, the sensors used are mainly optical devices (such as cameras) and optoelectronic devices (such as TV cameras), the basic principle of which is the same as that of common devices, but the design changes to make it more suitable for long distance applications