Why can the United States monitor the whole process of rocket launch on the ground, while China only monitors the rocket launch for a few seconds?

First of all, I didn't see the whole surveillance in America. If there is such a video, please show it to me.

Secondly, what kind of monitoring are you talking about? Radar monitoring or optical monitoring. Broadcasting with analog images does not mean that there is no monitoring. In fact, the main monitoring equipment is radar rather than camera.

Thirdly, as far as I know, no country in the world can monitor the whole process of rocket launch through video, or no country in the world can provide real-time video recording of the whole process of rocket launch. Because the observation range of optical instruments is limited, it is not practical to track rockets flying at Mach 10 by aircraft. Therefore, under normal circumstances, the live broadcast can only see the separation of the first and second stage rockets at most.

Finally, Chang 'e II was launched in bad weather conditions, which ensured the launch of Window 0. A few seconds after takeoff, the rocket flew into the clouds, which was impossible to see with optical equipment. The launch weather of Shenzhou is generally good, so the live video signal you can see can last for at least three or four minutes, and the video signal provided by the camera installed outside the spacecraft can be provided until it is in orbit.