NTP Server Static GPS Antenna Systems
The Global Positioning System (GPS) is often used by computer systems such as NTP Server, to provide an accurate reference clock for time-critical applications. This article provides an overview of GPS applications schedule and description of equipment used to install a GPS antenna in a static place.
Overview – Using GPS to get the time
The Global Positioning System is a system of U.S. military navigation worldwide. The system consists of 24 satellites in orbit, each satellite has a high-precision atomic clock synchronized with the on-board UTC time. The satellites continuously broadcast time and position. The time and location information can be obtained worldwide with a GPS receiver and antenna. GPS works continuously in any whether conditions, anywhere in the world. Besides the charges, no membership fee or use GPS systems. Many computer timing systems and NTP server systems use GPS as an external timing reference accurate.
Accuracy of GPS synchronization systems
GPS receivers provide highly accurate position and timing information. Usually, a GPS receiver can provide position information with an accuracy of 15 meters. NTP Server systems can get the GPS timing information to a resolution of a few nanoseconds.
The GPS signal
The GPS signal transmission is the radio signal very weak low-power, designated L1 and L2. L1 GPS frequency is transmitted civil 1575.42 Mhz. The signals travel by line of sight and can pass through clouds, glass and plastics but are blocked by objects such as metal and masonry. Therefore, the ideal place for a GPS antenna is on the roof with a full 360 degree view of the sky. However, often the installation on the side of a building or a window can provide adequate results. As a general rule, the best view of the sky, the greater the chance of a coherent signal blocking good.
Type Antenna GPS synchronization
The GPS antenna acts as an amplifier to boost the GPS signal for transmission over a cable, typically coaxial, GPS receiver. Weather GPS antenna fitted with NTP server systems use a pole mounting system. The antenna screws to a threaded pole for installation in roofs. This agreement provides the GPS antenna with a rigid mount easily able to withstand high winds without damage. Normally the GPS antenna is quite small in size, measuring less than 90cm in diameter. Low-cost patch antennas are also available, but are generally more suitable for vehicle applications.
GPS antenna cable cable types and distances
The cable length can be used by a GPS antenna depends mainly on the amplification of the GPS antenna and quality of coaxial cable used in the installation. A typical GPS antenna time may have a gain of 35 db. Relatively low quality coaxial RG58 has an attenuation 0.64 dB / m at 1575 MHz, therefore, a cable run of 55m can be obtained with RG58 cable. With a very high quality coaxial cable such as LMR400, a cable of 200 meters unaided term can be achieved. However, very high quality coaxial cable can be expensive. A good compromise for money is LMR200 cable, which can be run without the aid of 80 million.
The extension wiring in line with GPS Distance Amplifiers
GPS Online amps provide additional amplification of the GPS signal increase the cable distance between the antenna and GPS receiver. amplifiers are equipped in line with the GPS antenna cable and the receiver gain power through cable coaxial. No external power supplies are required. Usually, a GPS amplifier can add another 20 dB of gain, adding 30 meters RG58 coaxial low quality, 40 meters LMR200 or LMR400 coaxial cable 100 meters of high quality coaxial cable. In addition, several line amplifiers can be used to further increase cable distance.
Sharing a single antenna between several receivers – GPS Splitter
GPS splitters allow a single GPS antenna to be used by two or more NTP server systems. GPS splitter divides the signal received from the GPS antenna on multiple outputs for synchronizing multiple NTP servers. GPS dividers are generally Available with 2, 4 or 8 outputs.
The protection of GPS – GPS Surge Suppressors
Surge suppressors protect expensive NTP server electrostatic discharge equipment, such as lightning, which can be collected by a GPS antenna mounted on the exterior. Surge suppressors are installed in the cable line coax between the antenna and receiver, the ideal would be that the cable enters the building. surge suppressors require a low impedance ground in order to download any increase received. The surge suppressor does not require additional power or wiring.
About the Author
Dave Evans develops atomic clock time synchronisation systems to ensure accurate time on PC networks. Click here to find out more about GPS NTP Server systems.
