- #1
PikesPeak
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- 0
Hi all,
I'm working on a satellite simulation, and I need to convert heliocentric coordinates to geocentric coordinates. I get the heliocentric coordinates from Celestia for two objects – the Earth and a satellite. The satellite's +Z axis points to the center of the earth, and the +X axis points down the line of travel, so I can get the orientation of the satellite from there.
Since I know the time of the simulation, I can use G. D. Mead’s Fortran routine to get Greenwich Mean Sidereal Time, Longitude along the Ecliptic, and Apparent Right Ascension and Declination of the sun over the earth. I have all of that working.
My question is how to use the data from Mead’s routine to first get the orientation of the earth’s axes, and then the orientation of the satellite in Earth centric coordinates.
Am I heading down the right path? I know this is not that hard of a problem, I just don’t know how to get there.
Thanks in advance!
I'm working on a satellite simulation, and I need to convert heliocentric coordinates to geocentric coordinates. I get the heliocentric coordinates from Celestia for two objects – the Earth and a satellite. The satellite's +Z axis points to the center of the earth, and the +X axis points down the line of travel, so I can get the orientation of the satellite from there.
Since I know the time of the simulation, I can use G. D. Mead’s Fortran routine to get Greenwich Mean Sidereal Time, Longitude along the Ecliptic, and Apparent Right Ascension and Declination of the sun over the earth. I have all of that working.
My question is how to use the data from Mead’s routine to first get the orientation of the earth’s axes, and then the orientation of the satellite in Earth centric coordinates.
Am I heading down the right path? I know this is not that hard of a problem, I just don’t know how to get there.
Thanks in advance!