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  1. Mick West

    Mick West Administrator Staff Member


    Source: https://www.youtube.com/watch?v=bIA-x0QGBp0


    Some people think space, and hence the existence of satellites, is fake.
    The most obvious refutation of this is that you have to point your satellite dish exactly at the right satellite in the sky for it to work. There's no way of faking this. There's nothing else up there. But how to test this without throwing your dish out of alignment.
    Here I hold up a metal object at 45° in front of the dish, the signal is lost, which shows the signal is coming from space.

    The actual incoming angle is quite a bit steeper than it looks from the disk, as it uses an offset focus. This allows for easier mounting. Most dishes in the US are pointed at around 40-45°
    Metabunk 2019-05-18 08-58-43.

    With it being so steep it was a bit tricky to hold the metal tub in the right place. A more ambitious experiment might be to make a shield from a sheet of cardboard covered in aluminum foil and mounted on a pole.

    To find out the angle and visualize all the geostationary statellites there's a variety of apps. One free one is "Satellite Pointer"
    Metabunk 2019-05-18 09-12-29.
    (Coordinates just set to Sacramento)

    That looks like where the dish is pointing, 45° up. and 176° is nearly due south (180°).

    You could do the rough math here. Assuming the satellite is one that's pretty much due south, all geostationary satellites are 22,300 miles above the equator. Sacramento is about 38.5° north, the radius of the Earth is about 3959 miles
     
    Last edited: May 18, 2019
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  2. Astro

    Astro Active Member

    On the 18th I tracked the Hubble Space Telescope based on its orbit and with my telescope I was able to just barely resolve the shape of HST as an elongated tube, not just a round point like light source.

    Checking the schedule, I found HST was supposed to be observing a quasar near the handle of the big dipper at that time. I ran a simulation using Hubble's actual orbit and a virtual Hubble pointed at the same coordinates. Sure enough, when observed from my location the simulation showed a prefeperfect match for the observed attitude of HST as seen in my telescope.


    A balloon or drone at a lower altitude would not be at the expected location in the sky for an arbitrary observer at an unknown location. And of course, with multiple simultaneous observers it's possible to directly measure the altitude and velocity of Hubble via parallax. I've done that with the help of a friend to measure ISS, but I may do something similar in the future with Hubble as well if my friend acquires a similar telescope as he's currently planning to do.
     
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  3. Rory

    Rory Senior Member