"We have the tyranny of distance - this harbours a spirit of" we need to do it ourselves because we can't rely on getting external help ", Oostveen says."
“我们有距离的折磨-这个港口有一种精神“我们应该自己解决而不是依赖外面的帮助”，奥斯蒂文说。”
2
Or you might use long-distance communication lines, telephone lines, located close to the external data unit information.
或者你可能使用远程通讯线、电话线、接近位于外部数据单元的信息。
3
A simple inertial or Doppler navigation has a common defect that position errors are always increasing with flight time or distance, therefore an external reference system is necessary.