The geocentric equatorial coordinates (R.A. and Dec.) of the satellite are known, but they are useless to observers on the surface of the Earth. We need to translate these coordinates to a location on the surface of the Earth that we wish to observe the satellite from. First, we need to convert the satellite polar coordinates (r(t), a_{g}, d_{g}) into their equivalent Geocentric Cartesian Coordinates (x_{g}, y_{g}, z_{g}) using the following equations:
x_{g} = r(t)cosa_{g}cosd_{g}
x_{g} = 5348.663965 km In order to confirm that the Cartesian coordinates have been calculated correctly, add the sum of the squares of the answers and take the number's square root. The number you finally arrive at should be the original geocentric satellite distance, r(t): x_{g}^{2} + y_{g}^{2} + z_{g}^{2} should = r(t)^{2 } |
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Step 10: Geocentric Cartesian Was Last Modified On April 01, 2014 |