ag, dg

 Element Symbol Value Epoch to 05:54:21.171 UTC December 16, 2007 Inclination i 51o.9970 R.A. of the Ascending Node aW0 251o.0219 Eccentricity e 0.0001492 Argument of Perigee w0 33o.8641 Mean Anomaly at TLE Epoch Mo 326o.2322 Mean Motion n 12.62256095 orbits / solar day Propagation Time Dt 1.7677141 solar days Mean Anomaly at Time t M(t) 1.37777389 radians (78o.940629) True Anomaly at Time t n(t) 78o.95065818 Semi-major Axis a 7791.787473 km Perigee Distance P 7790.624938 km Geocentric Distance r(t) 7791.564499 km Precessed R.A. of Asc. Node aW(t) 245o.6400244 Precessed Arg. of Perigee w(t) 37o.77767416 Argument of Latitude m(t) 116o.7283323 R.A. Difference Da 129o.278845

The R.A. Difference is the difference between the Geocentric Right Ascension of the satellite and its (precessed) R.A. of Ascending Node:

Da = ag - aW(t)

Rearranging the terms, the Geocentric Right Ascension (ag) coordinate of the Satellite can be found by using the following equation:

ag = Da + aW(t) - 360o { INTEGER [ (Da + aW(t)) / 360o ] }

ag = 14o.9188694

The Geocentric Declination (dg) coordinate of the satellite can be determined by using the following equation:

dg = [SIGN (sinm(t))] cos-1 [ cosm(t) / cosDa ]

IMPORTANT NOTE: When using this equation, please keep in mind that the SIGN (sinm(t)) term means that only the sign of the result is to be used (+1 or -1) and not the value of the sine itself. SIGN (sinm(t)) is used only to determine the sign of the geocentric declination (above or below the celestial equator).

dg = +44o.73125163

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 SITE MAP Step 9: Finding the Geocentric Coordinates Was Last Modified On April 01, 2014