Remote sensing information is the synthetical reflection of the earth surface with definite scale space.

遥感信息主要反映的是地球表层信息。

The main idea is to find extreme value in the scale space, extracting location, scale and rotation invariant.

它最初作为一种关键点的特征提出来的，其主要思想是在尺度空间寻找极值点，提取位置，尺度，旋转不变量；

One of the most difficult problems in designing large-scale space antenna is how to solve the in-step motion.

空间展开天线大型化所遇到的关键难题之一是如何解决协调运动。