A pass of a satellite occurs whenever it rises above the observer's horizon; a visible passoccurs when all three of the above conditions are satisfied, so the sunlit satellite is seen against a dark sky - this will generally occur either shortly after sun
A pass of a satellite occurs whenever it rises above the observer's horizon; a visible passoccurs when all three of the above conditions are satisfied, so the sunlit satellite is seen against a dark sky - this will generally occur either shortly after sun
不论卫星何时从观测者地平线之上穿过，都会形成卫星路径；但是卫星经过的“可见路径”只有在满足上面所有三个条件的时候才可以形成，有此看来，只有被日光照射的人造卫星必须与暗背景对比才能被观测到-这经常要在太阳刚刚落山或者太阳将要升起之前。