Abstract：From the mechanism of optical sensing, color sensing and shape sensing of human eyes, this paper shows that the plane shape sensing and solid shape sensing depend on the size and the distance of the observed objects. With this point of view in mind and with the main research results of the Great Wall remote sensing image processing, various statements on this issue are analyzed and it is shown that human eyes can not see the Great Wall from space orbit, which can only be seen from the Great Wall image of high spatial resolution satellite sensing.
2007, Vol. 25 
