I'm going to talk to you today about the classification of remote sensing [Music] remote sensing is classified into two active and passive so what is active active is when the sensor embodies within itself the source of illumination we had cameras which used to have a built-in flash on them so the moment you click the picture the flash would fire the light from the flash would get reflected from the object and the camera would record a picture so in this case the camera is also carrying the source of illumination I have put it rather very simply
when it comes to sense of stricto active remote sensing we understand active remote sensing as in radar because when you have a satellite which is equipped with a radar transponder its sending out radar waves or radio waves which bounce off from the Earth's surface the time required for the waves to hit the Earth's surface and we recorded by sensors on the satellite is what is utilized for making an image it's an excellent example of active remote sensing [Music] what's happening right now is remote sensing there's a digital camera in front of me it's amazing me
now collecting data or photographing me only because I'm being illuminated by two spotlights this is very similar to how Sun illuminates the earth and reflectance from the Earth's surface is collected by the satellite so the sensor itself is not having a source of illuminating the ground surface or the object which it is imaging the Sun earth and satellite sensor example is a classic to understand passive remote sensing its passive because the sensor is not carrying its own source of energy just like right now this standalone camera does not have its own illumination source or what
I have just told you in very simple terms is the basic classification of the technology of remote sensing so with that we've defined very precisely the two types of remote sensing thank you [Music] you
