GPS Auto Tracker - Definition of GPS Systems
August 7, 2009 by GPS and Navigation System Tips
Filed under About GPS
Before the arrival of the General Positioning System (GPS) technology, having a trip was certainly the most daunting experience in our life. For instance, it was perfectly acceptable to see a situation where someone was driving his car, another one was looking at the map to find the right direction, quite funny! Nowadays, this situation is obsolete and ridiculous for GPS systems have drastically changed the way we used to deal with route finding during a trip. Indeed by just installing a GPS device in your car, you can accurately and safely get the right direction.
Usually when someone mentions GPS, he is referring to the GPS receiver even if the GPS architecture is actually more complex than this small device installed in your car. In short, GPS systems are a cohort of 27 satellites rolling around the center of the Earth. Only 24 satellites are fully functional while the remaining ones are just used for storage purposes. The military industry pioneered the technology before being used for general purpose by the public.
Each GPS satellite powered by the Sun rotates around the center of the Earth completes a distance of about 12,000 miles which is equal to 19,300 kilometers. The actual trajectories of these satellites are made so that at least four satellites are available in the space at any time. The GPS receiver is responsible of finding these available satellites, working out its distance to these satellites and finding its position. This process makes use of a mathematical model called trilateration.
The GPS signals are hindered by weather conditions. Nowadays, there are many research projects aiming at finding ways around this issue in order to increase the correctness of GPS systems. Having located the satellites, the triliteration is used to work out its distance and reduce these errors.
Briefly speaking, GPS systems are used for several purposes mainly as guiding aid. The user simply needs to input his final destination and the GPS receiver will do the rest of the job. GPS systems can also be used for tracking purposed as it is noticed in the automobile industry.
The GPS technology is also used for many other purposes. For instance, in the automobile industry, GPS systems are used to deter car thieves. Private investigators are also making use of the GPS technology in order to monitor a cheating wife. The GPS technology is also extensively used in the military industry as it was pioneered by the army. Some military usages include navigation, target tracking, missile and weapon guidance, search and rescue lost soldiers and acknowledgement and map creation. The possibility to keep track of a vehicle position every time is an appealing feature of the GPS technology. Other systems can furthermore keep track of a driver. This feature is of great help to anxious parents who are concerned about their children’s ability to safely drive.
Another use of the GPS for civilian purpose is to help prevent civilian GPS guidance from being used in an enemy’s military or improvised weaponry, the US Government controls the export of civilian receivers. A US-based manufacturer cannot generally export a GPS receiver unless the receiver contains limits restricting it from functioning when it is simultaneously at an altitude above 18 kilometers and traveling at over 515 m/s.
Thanks to John B. Mayall for contributing this article to our GPS blog:
Usually when someone mentions GPS, he is referring to the GPS receiver even if the GPS architecture is actually more complex than this small device installed in your car. In short, GPS systems are a cohort of 27 satellites rolling around the center of the Earth. Only 24 satellites are fully functional while the remaining ones are just used for storage purposes. The military industry pioneered the technology before being used for general purpose by the public.
Each GPS satellite powered by the Sun rotates around the center of the Earth completes a distance of about 12,000 miles which is equal to 19,300 kilometers. The actual trajectories of these satellites are made so that at least four satellites are available in the space at any time. The GPS receiver is responsible of finding these available satellites, working out its distance to these satellites and finding its position. This process makes use of a mathematical model called trilateration.
The GPS signals are hindered by weather conditions. Nowadays, there are many research projects aiming at finding ways around this issue in order to increase the correctness of GPS systems. Having located the satellites, the triliteration is used to work out its distance and reduce these errors.
Briefly speaking, GPS systems are used for several purposes mainly as guiding aid. The user simply needs to input his final destination and the GPS receiver will do the rest of the job. GPS systems can also be used for tracking purposed as it is noticed in the automobile industry.
The GPS technology is also used for many other purposes. For instance, in the automobile industry, GPS systems are used to deter car thieves. Private investigators are also making use of the GPS technology in order to monitor a cheating wife. The GPS technology is also extensively used in the military industry as it was pioneered by the army. Some military usages include navigation, target tracking, missile and weapon guidance, search and rescue lost soldiers and acknowledgement and map creation. The possibility to keep track of a vehicle position every time is an appealing feature of the GPS technology. Other systems can furthermore keep track of a driver. This feature is of great help to anxious parents who are concerned about their children’s ability to safely drive.
Another use of the GPS for civilian purpose is to help prevent civilian GPS guidance from being used in an enemy’s military or improvised weaponry, the US Government controls the export of civilian receivers. A US-based manufacturer cannot generally export a GPS receiver unless the receiver contains limits restricting it from functioning when it is simultaneously at an altitude above 18 kilometers and traveling at over 515 m/s.
Thanks to John B. Mayall for contributing this article to our GPS blog:
Find out more on where to get map for gps handheld and learn what is the best gps system from internet most popular GPS auto tracking site, http://www.gpsportabletracking.com
Network Time Synchronization Through GPS Time Servers
July 19, 2009 by GPS and Navigation System Tips
Filed under About GPS
Copyright (c) 2007 Galleon Systems
This article explains how GPS Time server Systems achieves exact timing information to give a highly accurate timing reference for Network Computer time.
GPS System is a navigation system operated by the Military but also can be used by the civilian and does not need any subscription. The GPS System is known as an extremely accurate global positioning system. Each GPS satellite has an onboard a highly accurate atomic clock, ideal for supplying the correct time for computer network time synchronization.
GPS Time Servers: The GPS System exist of a constellation of 24 orbiting satellites, each has a precise atomic clock timing reference and covers the entire globe. The exact time information can be continuously broadcast from each of the satellites. You can receive the broadcast timing information with a relatively low cost GPS antenna and receiver.
GPS time is transmitted as Universal Coordinated Time (UTC), which is similar to Greenwich Mean Time (GMT). The UTC time is the same worldwide and does not vary regarding the time zone or daylight saving time. UTC is a very accurate atomic time standard sustained by atomic clocks located in national standards laboratories. UTC has consistent seconds distinct by the International Atomic Time (TAI) Institute.
GPS Radio Transmission: The GPS satellites broadcast information as very low-power radio frequency transmission. There are two designated frequency that are used, one for civilian use coded L1 and the Military use coded L2.The civilian L1 frequency is transmitted at 1575MHz. It can easiliy pass through plastic and glass but is blocked by metal and brick.
GPS Antenna Location: The precondition to receive transmission from as many satellites as possible is a good clear view to the sky. Ideally a roof mounted antenna is best with a full 360-degree view of the sky. Conversely, an antenna can be located on the side of the building with a 180-degree view of the sky if the horizon is not too obscured.
GPS Antenna Types: The GPS antenna is essentially a signal amplifier. The antenna improves the received GPS signals for transmission along a cable to a receiver for decoding. A Coax Cable is normally used to transfer signal information between the GPS antenna and receiver. These antennas can be provided in different shapes and sizes. The general antennas being pole-mounted are dome shaped antennas and small patch type antennas. The pole-mounting antenna screws onto the threaded pole for mounting. Whereas the patch type antenna is a small flat bottomed device ideal for mounting on a windowsill.
GPS Receivers: GPS Receivers decipher the GPS transmission received from the antenna into a useable format. NMEA is the most common protocol used by the GPS receiver. This protocol insists a number of sentences which provide a packet on information confirm of time, date and positioning information. The NMEA protocol quotes information indicating visible satellites and satellite location.
GPS time servers can use a specific GPS timing receiver. These timing receivers have additional functions to provide a highly accurate reference time. The timing receiver can also perform an automated survey and compare satellite atomic clocks to check for synchronicity. GPS time servers may also use an accurate pulse per second (PPS) output, which provides a highly accurate reference trigger for GPS timing, generated by the receiver.
GPS Antenna Installation: The gain of the antenna and the coax is important for the maximum cable distance that can be used by a GPS antenna and receiver. An antenna used with a GPS time server may have 35dB gain. RG58 coax has an attenuation of 0.64dB/m at 1575MHz. Therefore a cable length of 35/0.64=55m could be used. Higher quality coax has a much lower attentuation value allowing longer cable runs. Also GPS amplifiers and updown converters can be utilized to increase the cable length. Surge lightening arrestors are also recommended on externally mounted GPS antenna to protect expensive network equipment from potential damage by lighting strikes
Thanks to Magdalena Sperber for contributing this article to our GPS blog:
This article explains how GPS Time server Systems achieves exact timing information to give a highly accurate timing reference for Network Computer time.
GPS System is a navigation system operated by the Military but also can be used by the civilian and does not need any subscription. The GPS System is known as an extremely accurate global positioning system. Each GPS satellite has an onboard a highly accurate atomic clock, ideal for supplying the correct time for computer network time synchronization.
GPS Time Servers: The GPS System exist of a constellation of 24 orbiting satellites, each has a precise atomic clock timing reference and covers the entire globe. The exact time information can be continuously broadcast from each of the satellites. You can receive the broadcast timing information with a relatively low cost GPS antenna and receiver.
GPS time is transmitted as Universal Coordinated Time (UTC), which is similar to Greenwich Mean Time (GMT). The UTC time is the same worldwide and does not vary regarding the time zone or daylight saving time. UTC is a very accurate atomic time standard sustained by atomic clocks located in national standards laboratories. UTC has consistent seconds distinct by the International Atomic Time (TAI) Institute.
GPS Radio Transmission: The GPS satellites broadcast information as very low-power radio frequency transmission. There are two designated frequency that are used, one for civilian use coded L1 and the Military use coded L2.The civilian L1 frequency is transmitted at 1575MHz. It can easiliy pass through plastic and glass but is blocked by metal and brick.
GPS Antenna Location: The precondition to receive transmission from as many satellites as possible is a good clear view to the sky. Ideally a roof mounted antenna is best with a full 360-degree view of the sky. Conversely, an antenna can be located on the side of the building with a 180-degree view of the sky if the horizon is not too obscured.
GPS Antenna Types: The GPS antenna is essentially a signal amplifier. The antenna improves the received GPS signals for transmission along a cable to a receiver for decoding. A Coax Cable is normally used to transfer signal information between the GPS antenna and receiver. These antennas can be provided in different shapes and sizes. The general antennas being pole-mounted are dome shaped antennas and small patch type antennas. The pole-mounting antenna screws onto the threaded pole for mounting. Whereas the patch type antenna is a small flat bottomed device ideal for mounting on a windowsill.
GPS Receivers: GPS Receivers decipher the GPS transmission received from the antenna into a useable format. NMEA is the most common protocol used by the GPS receiver. This protocol insists a number of sentences which provide a packet on information confirm of time, date and positioning information. The NMEA protocol quotes information indicating visible satellites and satellite location.
GPS time servers can use a specific GPS timing receiver. These timing receivers have additional functions to provide a highly accurate reference time. The timing receiver can also perform an automated survey and compare satellite atomic clocks to check for synchronicity. GPS time servers may also use an accurate pulse per second (PPS) output, which provides a highly accurate reference trigger for GPS timing, generated by the receiver.
GPS Antenna Installation: The gain of the antenna and the coax is important for the maximum cable distance that can be used by a GPS antenna and receiver. An antenna used with a GPS time server may have 35dB gain. RG58 coax has an attenuation of 0.64dB/m at 1575MHz. Therefore a cable length of 35/0.64=55m could be used. Higher quality coax has a much lower attentuation value allowing longer cable runs. Also GPS amplifiers and updown converters can be utilized to increase the cable length. Surge lightening arrestors are also recommended on externally mounted GPS antenna to protect expensive network equipment from potential damage by lighting strikes
Thanks to Magdalena Sperber for contributing this article to our GPS blog:
The author; Magdalena Sperber is a technical writer with a background in computer network timing. Magdalena provides a technical authoring service for NTP Server and GPS NTP time reference manufactures.
