遥感（英语：remote sensing），广义是指用间接的手段来获取目标状态信息的方法。但一般多指从人造卫星或飞机对地面观测，通过电磁波（包括光波）的传播与接收，感知目标的某些特性并加以进行分析的技术。

根据遥感平台分类，遥感可分为机载（airborne）遥感和星载（satellite-borne）遥感，其中机载遥感是飞机携带传感器（CCD相机或非数码相机等）对地面的观测，星载遥感是指传感器被放置在大气层外的卫星上。

根据传感器感知电磁波波长的不同，遥感又可分为可见光—近红外（visible–near infrared）遥感、红外遥感及微波遥感等；根据接收到的电磁波信号的来源，遥感可分为主动式（信号由感应器发出）和被动式（信号由目标物体发出或反射太阳光波）。

Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to on site observation. Remote sensing is used in numerous fields, including geography and most Earth Science disciplines (for example, hydrology, ecology, oceanography, glaciology, geology); it also has military, intelligence, commercial, economic, planning, and humanitarian applications. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth (both on the surface, and in the atmosphere and oceans) by means of propagated signals (e.g. electromagnetic radiation). It may be split into active remote sensing (when a signal is first emitted from aircraft or satellites) or passive (e.g. sunlight) when information is merely recorded.