北斗简述（Beidoubriefly）.doc

北斗简述（Beidou briefly）
北斗简述(Beidou briefly)
The navigation system
In the area of satellite navigation technology, the device. The principle of "beidou" number one brings two problems, one is the user to locate the lost the concealment of the radio at the same time, it will be very bad on the military, on the other hand, the equipment must include the transmitter, so on the size, weight, price and power at a disadvantage.
4. Positioning accuracy: the 3d positioning accuracy of beidou navigation system is about a few tens of meters, and the timing accuracy is about 100ns. The GPS 3d positioning accuracy P code is now increased from 16m to 6m, and C/A code is now increased from 25-100m to 12m, which is about 20ns before the time of insemination.
5, user capacity: the beidou navigation system because it is the active two-way ranging inquiries - response system, between the user equipment and geostationary satellites not only ask signal receiving ground center control system, also requires a user equipment to the synchronous satellite launch response signal, so that the user of the system capacity depends on the channel user allow , ask signal rate and frequency of the user's response. Therefore, the user device capacity of the beidou navigation system is limited. GPS is a one-way distance measurement system, and the user's equipment can be
located by the navigation satellite sent by the navigation satellite, so the capacity of the user device of GPS is unlimited.
6, viability, and all the navigation and positioning satellite systems, "beidou no. 1" based on centralized control system and satellite work, but the "beidou no. 1" on the dependence of the center control system are much bigger,
Because the location solution is there and it's not done by the user device. In order to compensate for this system vulnerability, GPS is developing the interplanetary data link technology to enable GPS satellites to operate independently if the main control stat