序言关于从人造地球卫星的高度对地球进行侦察效果的论文发表以来,已经六年多了。在实际应用的过程中,侦察卫星在技术上也得到了不断的改进,这是因为曾对几次战事进行过实际侦察而积累了经验。这样,在使用技术方面也有了很大进步。六年以前较难达到的侦察效果,现在也已获得了。 The preamble has been more than six years since the publication of the paper on the effect of reconnaissance of the Earth from the height of artificial Earth satellites. In practical application, reconnaissance satellites have also been technically improved because of the experience gained in conducting actual reconnaissance on several occasions. In this way, there has also been a great improvement in the use of technology. The scouting effect harder to reach six years ago has now also been obtained.