ABSTRACT
Photography from aerial platforms was initially conducted using ornithopters, balloons, kites, pigeons, and gliders. The term "remote sensing" was first coined by Evelyn Pruitt of the US Office of Naval Research in the 1950s, and the traditional aerial photography gradually evolved into remote sensing around 1960. There are two types of remote sensing systems: passive and active. A new era of spaceborne remote sensing began when the Explorer VI of the United States obtained the first satellite picture of the Earth in August 1959. From 1959 to 1972, Corona satellites of the United States were used for photographic surveillance. A radar remote sensing system uses its own electromagnetic energy in microwave bands to "illuminate" the terrain and detects the energy returning from the terrain, with the transmitter and the receiver in the same location. LiDAR stands for Light Detection and Ranging, a technology that measures distances based on the time between transmitting and receiving laser signals.
