Sounds like the Chinese are proving the Flat Earth community is right after all (and that God created the Earth and the universe as well). 
At 45 kilometers, how do you know where to point the telescope to find your subject?"
Even more interesting is that the "curve of the earth" would prohibit any photography shot from a straight line of sight from 45 km or about 28 miles away of anything but a building about half the height of the Empire State Building.
If you were trying to shoot something 45 km or 28 miles away, your object would be about 520 feet under the horizon line (somewhat less if you held the camera at eye height of five feet) or "under the curve" ... completely outside any direct line of sight, unless you were shooting a building that was taller than 520 feet...
and then you would only see the very top of the building at 28 miles away: http://earthcurvature.com/
https://dizzib.github.io/earth/curve-calc/?d0=28&h0=6&unit=imperial
Earth Curvature Calculator
by NyttNorge.com
Accurately calculate the curvature you are supposed to see on the ball Earth.
Distance.........Curvature
1 mile...........0.00013 miles = 0.67 feet
10 miles.........0.01263 miles = 66.69 feet
50 miles.........0.31575 miles = 1667.17 feet
100 miles .......1.26296 miles = 6668.41 feet
200 miles....... 5.05102 miles = 26669.37 feet
500 miles .......31.5336 miles = 166497.53 feet
1000 miles.......125.632 miles = 663337.65 feet
Explanation: The Earth's radius (r) is 6371 km or 3959 miles, based on numbers from Wikipedia, which gives a circumference (c)of c = 2 * π * r = 40 030 km
We wish to find the height (h) which is the drop in curvature over the distance (d)
Using the circumference we find that 1 kilometer has the angle 360° / 40 030 km = 0.009°.
The angle (a) is then a = 0.009° * distance (d)
The derived formula h = r * (1 - cos a) is accurate for any distance (d)
That's just an average. It is that value plus or minus about 6 miles. That has consequences.
Another issue: at a resolution of 60cm, the resulting “image” of an individual is going to be 3 or 4 pixels - NOT a lot of information detail to be had.
A two story building has 10 or 15 pixels high if you can move beyond earth curvature type issues
The technical barriers prevent this from any potential usefulness - now and for a very long time...
Thank you, that is just what I was needing, my first thought was curvature of the earth, Dad had said we can only see about 25 miles at best.
The refraction from the Earth’s atmosphere lets you see stars 2 degrees below the horizon. I don’t know how that would translate for an object on the surface.
Sounds like the Chinese are proving the Flat Earth community is right after all (and that God created the Earth and the universe as well).
down and dirty is Sqrt 3/2HGreat point.
I completely forgot about the curvature of the Earth.
And thanks for the math class!