AP7 – 98 – ANNEX 6 Supplementary and auxiliary contours MOD 4 Determination of a supplementary contour using the time-variant gain (TVG) method The TVG method requires the cumulative distribution of the time-varying horizon antenna gain of an earth station operating with a non-geostationary space station. In comparison to the TIG method, the TVG method usually produces smaller distances, but requires greater effort in determining the cumulative distribution of the horizon gain of the earth station antenna for each azimuth to be considered. AP7A5-08 0° 5° 2° 10° 20° 50° 100° 200° 0° 20° 40° 55° 65° 70° 75° 78° 77° = 0° 20° 40° 60° 80° 100° 120° 140° 160° 180° 200° 220° 240° 260° 280° 300° 320° 340° 360° r =180° 200° 220° 240° 260° 280° 300° 320° 340° 360°/0° 20° 40° 60° 80° 100° 120° 140° 160° 180° r =360°/0° = 180° r =180° = 360°/0° =180° 200° 220° 240° 260° 280° 300° 320° 340° 360°/0° 20° 40° 60° 80° 100° 120° 140° 160° 180° r = 0° 20° 40° 60° 80° 100° 120° 140° 160° 180° 200° 220° 240° 260° 280° 300° 320° 340° 360° FIGURE 8 Illustration of minimum angular distance between points on the geostationary-satellite orbit (GSO)and the horizontal plane Southern Hemisphere Northern Hemisphere (Minimum elevation angle, min = 3°)Minimum angle between the horizontal plane and the GSO (degrees)Station latitude, 78.3°