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Hi everyone,
I was wondering if anyone knows the methods used by MapMFD to plot:
a) ground tracks
b) the horizon visible to the spacecraft
c) the terminator between day/night (and the shading of the day/night areas)
I guess for the ground track, it could perform a series of forward propagations, store them in sequence, and connect each of these dots with a line, but this seems pretty brute-force. I can't think how the horizon and day/night terminator could be drawn unless there's a pixel shader which is performing calculations on every pixel on the map to see if it's visible to the spacecraft/sun.
Perhaps there is some source code for MapMFD or one that does similar plots? I'd be very interested in knowing how to do these plots in a program of my own using vector graphics if possible.
Thanks!
I was wondering if anyone knows the methods used by MapMFD to plot:
a) ground tracks
b) the horizon visible to the spacecraft
c) the terminator between day/night (and the shading of the day/night areas)
I guess for the ground track, it could perform a series of forward propagations, store them in sequence, and connect each of these dots with a line, but this seems pretty brute-force. I can't think how the horizon and day/night terminator could be drawn unless there's a pixel shader which is performing calculations on every pixel on the map to see if it's visible to the spacecraft/sun.
Perhaps there is some source code for MapMFD or one that does similar plots? I'd be very interested in knowing how to do these plots in a program of my own using vector graphics if possible.
Thanks!