10 ms·

Can someone explain to my dumbass how they helped calibrate the photos or satellites?

• mabbo 10y ago
  Okay, I just spent 20 minutes trying to figure that out and I'm still not very far. These were film cameras, so the computer on board can't look through the camera and see if the objects are in focus, can they?
  • 13of40 10y ago
    They took a whole series of images at different focuses, then dropped it to earth and people radioed back the most in-focus setting....is how I'd do it.
  • idlewords 10y ago
    Heh, "computer on board". Waving my cane at you!
  • HeyLaughingBoy 10y ago
    Well, I'm going to assume there was no actual "computer" on board... However, a sharply focused image has more high-frequency components than a poorly focused one, so some sort of frequency discriminator (a technology from the 1920's IIRC) could possibly suffice to check and adjust focus. Remember that we've had sophisticated servomechanisms since WW2 so the feedback theory to do this was already well known. But that's just a guess...
• astrodust 10y ago
  They're spaced out over miles, so presumably they'd take a wide shot of a bunch of them and check that the focus on one side of the frame to the other would be consistent. Think of it as an eye chart for satellites.