• CrulOP
    1·
    1 year ago

    EDIT: I looked at the wrong instrument. See comments below to read about the MSS, “the oldest operational multispectral digital sensor”

    This is what I see from a quick search. According to Wikipedia page Landsat 1 - Sensors:

    ERTS-A had two sensors to achieve its primary objectives: the return beam vidicon (RBV) and the multispectral scanner (MSS).

    And from Return-Beam Vidicon (RBV) Overview:

    The Return-Beam Vidicon (RBV) sensor utilised vidicon tube instruments containing an electron gun that read images from a photoconductive faceplate similar to television cameras. The data stream received from the satellite was analog-to-digital preprocessed to correct for radiometric and geometric errors.

    So… if I understand it correctly, it was an analog camera which signal was at the end converted to digital. But please correct me if I’m wrong!

    ninja-EDIT: What happened on 1969, according to The First Digital Camera Was the Size of a Toaster - IEEE Spectrum:

    CCDs […] were invented in 1969 by Willard Boyle and George E. Smith at Bell Labs,

      • CrulOP
        1·
        1 year ago

        Ok, I looked at the wrong instrument.

        Regarding the MMS, here (page 3) it says:

        MSS sensor, the oldest operational multispectral digital sensor

        Then I found this diagram (with some explanations on this link):

        If I understand correctly, that means it has a 6 pixel-row resolution that it uses to scan a 2D area.

        Finally, I realized I was using a wrong idea of “digital camera”. There is no true “digital sensor”, all sensors are analog and always need a postprocess to convert to digital… right?

        As always, it’s impossible to provide a non-ambiguous definition. Is a 6-pixel row res instrument on a satelite a “digital camera”? … kind of :)

        Anyway, fascinating topic. Thanks for the input!