I was a radio ham in the early 70s used to hang out with some guys who were snarfing weather satellite data - essentially it worked this way - the satellites passed over and either spun along their axis or had a spinning sensor - that made a continual FSK signal (think a FAX signal, because it was intended to be downlinked to actual early fax machines) - we'd calculate the pass time and grab it on a big yagi steerwd manually (by listening to the noise floor).
In a dark room it would be played onto a TV screen with a very slow horizontal rate, vertical retrace would be done manually with a switch and the vertical increments were extracted form the signal. In front of the TV we'd place a bunch of cameras, we'd open the shutter at the start of the pass and close them at the end. At the end of the night we'd develop the film - the meteorology people who'd paid hundreds of thousands of $$ for ground stations were pissed that we were getting better quality images than their fax machines.
Also around midniught local time (in NZ) we'd pick up processed world images - 4 around each pole and 4 around the equator, with the country boundaries overlaid, and the communist countries carefully whited out
Yup it was really lo-res - it was the 70s the cold war was in full force - those screens were being put together by what at the time was called a 'super computer' probably not as powerful as your phone
In a dark room it would be played onto a TV screen with a very slow horizontal rate, vertical retrace would be done manually with a switch and the vertical increments were extracted form the signal. In front of the TV we'd place a bunch of cameras, we'd open the shutter at the start of the pass and close them at the end. At the end of the night we'd develop the film - the meteorology people who'd paid hundreds of thousands of $$ for ground stations were pissed that we were getting better quality images than their fax machines.
Also around midniught local time (in NZ) we'd pick up processed world images - 4 around each pole and 4 around the equator, with the country boundaries overlaid, and the communist countries carefully whited out