回复 'presto' 的评论 : Also your north/south velocity can't be right. Equator moves at 465m/sec, that's 360deg move. Immarsat satellite moves 2*1.6deg over 24hr period. Your 75m/sec is way off
weston 发表评论于
回复 'presto' 的评论 :
But the entry angle is ~10 N. So the north and south path can't be symmetric w.r.t. the satellite orbit. As long as this is true, whether it's 10deg or 5deg, the paths would have different relative velocities.
presto 发表评论于
回复 'weston' 的评论 :
The satellite currently has an orbital inclination of 1.6697°, which results in the maximum north/south velocity of the satellite of 75.8m/s. This is a reasonably large fraction of a Boeing 777's cruising velocity of ~ 450 knots = 232 m/s.
weston 发表评论于
回复 'presto' 的评论 : The angles would be different even after the first couple ping positions. The paths are part of two great circles that are not symmetric w.r.t to Equator. Some "experts" explanations are laughable b/c they haven't got the gist yet.
The inclined orbit makes little difference, i.e. the angle is very small typically less than 1deg. You can just use the Inmarsat-3 orbit as the new equator, and apply the above argument.
presto 发表评论于
回复 'weston' 的评论 :
南北的不同, 只能说明飞机从北到南刚过赤道的时候速度不一样。 In other words, it's only the first couple "ping"s that can tell the difference.
The more reasonable explanation I read is the satellite is not perfectly geostationary. It wobbles. Or has an angle with the equator. Hence the difference between the "north corridor" and the "south corridor".