"The original GPS design contains two ranging codes: the Coarse/Acquisition (C/A) code, which is freely available to the public, and the restricted Precision (P) code, usually reserved for military applications."
http://en.wikipedia.org/wiki/GPS_signals
GPS和北斗的民用信号都是免费的。
所有跟帖:
• 所以,准备换白菜价的设备 :) -航母01- ♀ (0 bytes) () 12/27/2012 postreply 14:53:52