Pseudo-satellite (Pseudo-Satellite or Pseudolite)

News】 【so-called pseudo-GPS satellites (Pseudo-Satellite or Pseudolite, abbreviated as PL), is laid on the ground fired a positioning signal transmitters are usually similar to the GPS signal transmitter. It is because of this reason, commonly referred to as pseudo-satellites are designed for the GPS pseudo-satellites. Of course, there are very few pseudo-satellite of its Galileo, or GLONASS signals are analog system, and even some special-purpose pseudo-satellite is defined by the positioning signal format.

In fact, the use of pseudo-satellite even earlier than the GPS itself. GPS in the early 70's pre-feasibility study stage, the U.S. Department of Defense before launching its first a GPS, and all concept testing and verification of the principle of GPS receiver laying on the ground through the "analog satellite" to complete, which is actually a pseudo-satellite. Parkinson and Klein in the early 80s to early pointed out the operation of pseudo-GPS satellites which can be an effective complement to technology, because it can improve the navigation performance and geometric precision. In the mid-80s, the International Organization developed the RTCM able to receive GPS satellite signals to calculate pseudorange and pseudo-range correction, and to 50 bits per second rate of L1 carrier frequency using a simple pseudo-launch navigation satellite system message, the pseudo-satellite GPS signal format is similar. After this, the international branch of RTCM SC104 organization has designed and developed the information contained eight pseudo-satellite ephemeris data formats, including pseudo-satellite location, code and health signs and so on. But subject to the constraints of hardware and software technology, its development has been slow.

With the new proposal of the concept of pseudo-satellite hardware technology continues to improve, pseudo-satellite positioning system has been in the room, underground, flight navigation, and other aspe