The only
real authorities in Vehicular Audio/Video Recording Systems
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The only
real authorities in Vehicular Audio/Video Recording Systems
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VSI+
GPS
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Protex has designed a special version of its Video Serial Interface (VSI+) for compatibility with a Global Positioning System Satellite Receiver (GPS), so that the text on the screen of a GPS navigational tool can be overlayed on the image being displayed on a video monitor. The VSI+GPS is compatible with most NEMA 0183 formats of GPS receivers, and can output a variety of informative text, such as Longitude, Latitude, Speed, Distance, and Bearing.Readings on Course Over Ground, Speed Over Ground, and Estimated Time of Arrival can be displayed on your video monitor. The VSI+GPS has powerful data processing programming for detecting certain ranges of data, actual latitude and longitude positions, and speeds greater or lesser or equal to a programmed speed. The EX Option can give open collector contacts output that will trigger when the above events occur. How GPS Works GPS is the super-accurate Global Positioning System that can fix your position within 100 meters horizontally and 156 meters vertically, anywhere on earth. GPS consists of 24 satellites in orbit above the earth. Their orbits are angled so that at least five satellites are always visible from any point on the earth’s surface at all times. The satellites were launched and are currently maintained by the U.S. Department of Defense for tactical and navigational use by the military. GPS receivers determine their position by measuring the time it takes the satellite’s signal to reach the receiver. The signal includes the time that it left the satellite. For a receiver to compute a position in four dimensions (X, Y, and Z spatial dimensions, and time), a GPS receiver needs to receive signals from at least four satellites. Each signal received by the GPS receiver produces a measurement called a pseudo-range. A pseudo-range is an imaginary sphere whose center is the satellite that is generating the signal. The intersection of the four spheres is what the receiver uses to determine its position. But since the GPS receiver’s internal clock can never be perfectly synchronized with the satellites’ atomic clocks, receivers usually use signals from five satellites in computing their position to allow for corrections. A moving receiver’s speed is measured by its changing position over time. The GPS signals use radio frequencies. This means a receiver must have an unobstructed line of site between it and the satellites. Metal and concrete will block the signals; however, non-metallic glass will allow the signal to pass through it. Thus GPS receivers will not work indoors, but will work in a car, as long as they are placed beneath the windshield. VSI+ Compatibility
View
the VSI+ GPS Install Sheet Prosecutor of Texas,
LLC. |
The
VSI and Global Positioning Systems 