What a load of BS

>>尊重不尊重，相信不相信，这都是个判断，网上这么多东西，关于弹道导弹打航母的科普，YST是独此一家<<

You can't be serious. Simply googling anti-ship ballistic missiles (AShBM) would turn up hundreds of pages of results, including explanation on it would work, from Rand Corporation to Popular Mechanics.

>>我们要看到YST究竟有什么长处，靠背工程教科书不算，靠常识想当然也不算<<

I don't know YST's education background and nor do you. His article provides one plausible mechanic how AShBM could work and I can't fault his logic.

>>凯普勒定律（Kepler's law）：十六世纪德国数学家和天文学家凯普勒（Johannes Kepler，1571~1630）在观察太阳系的行星时发现一个非常有趣的规律：

a.任何行星围绕着太阳运行形成一个通过太阳中心的平面，行星运行的轨道在这个平面上一定是一个椭圆（注意，圆是当椭圆长轴与短轴相等的一种特殊情况）；

b.如果你连接行星和太阳的中心就会形成一条直线，这条直线当行星运行的时候就会形成一个扇形的面积，虽然行星与太阳的距离随时都在改变，但是它在单位时间内所覆盖的扇形面积不会改变而是一个常数（constant）。

上面叙述的a与b就是天文学上非常有名和非常重要的凯普勒定律。 ”

大家能告诉我这玩意儿跟弹道导弹怎么打航母有关系吗？<<

Obviously you didn't read the YST article carefully enough. YST's point is that satellite could be very useful in detecting and tracking aircraft carrier battle groups. However he chose to expand on using OTH radars in his particular dissertations and I cannot see anything wrong with it.

To explain what YST was trying to say about satellites and Keplar's law, he was pointing out that spy satellites can be launched at a sharp inclination so that its perihelion would cover first and second island chain (approximately 2000 kilometers from China's coast) and its aphelion would be on the other side of the globe. Given Kepler's law, the satellites would cover the perihelion at a much faster velocity than its aphelion. This has 3 advantages: (1) much more difficult to shoot down given its high velocity, and (2) much quicker to cover the area it needs to cover (the 2000 kilometer range from China's coast), and (3) much harder to destroy as it reaches much higher altitude after passing through perihelion (such as when it's above the NORAD sky).

>>不过顺便说几句，地球卫星的轨道是不可以象行星那样用凯普勒定律（Kepler's law）滴，因为凯普勒定律用到卫星轨道上是非常粗糙的，这里的原因有几个，一个是地球的半径差不多是6,358公里比较地球卫星的高度还是挺大滴，因此把地球看成是质点的时候是会产生误差滴；二个是地球不是球，赤道半径与极半径差20多公里；三个是地球的质量分布不均匀，因此当卫星飞过地球的不同区域的时候受到的引力是跟地球的质量分布有关的，等等等等。<< 

Kepler's law is good enough to calculate approximate orbit of satellites just like Kepler's law is good enough to calculate approximate orbit of planets around the Sun. Just in case you forgot your Astrophics 101, Kepler's law is a specia case approximation under Newtonian Law of Motion.

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• a load of BS is talking a load of BS -jds- ♀ (0 bytes) () 06/12/2012 postreply 08:27:29