GPS stands for Global Positioning System, a satellite navigation system with twenty-four satellites in orbit. These satellites were put in place by the United States Department of Defense for military uses, and were called NAVSTAR. The first satellite was launched in 1978 and the twenty-fourth and last satellite was finally in place in 1994. In 1980 NAVSTAR was made available to the general public for commercial use.
GPS works 24 hours a day in any weather. The satellites orbit the earth twice a day in a specific orbit that is about 12,000 miles above us. In orbit, the satellites travel as fast as 7,000 miles an hour. As they are orbiting, they transmit information to receivers on earth. The receivers use this information to calculate the user’s location. This calculation is made by determining the difference between the time a transmission was made and when the receiver received it. This is then used to calculate the distance and the position is displayed on the receiver.
For a receiver to calculate a latitude and longitude position is to receive information from three satellites. To calculate latitude, longitude and altitude a receiver must be able to receive information from four or more satellites. After position is known the GPS can then tell the user information about speed, trip distance, the distance to a desired destination, sunrise and sunset times, bearing and other information.
While in orbit, the satellites are powered by solar energy. They also have backup batteries that are used in the event of no solar power such as an eclipse. The energy is used to power small rockets on the satellites that keep them in the proper orbit. At any one time only about 50 watts of power or less is used to transmit information. The satellites are designed to last about ten years, and the U.S. Department of Defense is constantly making and launching replacement satellites. Each satellite is about 2,000 pounds and seventeen feet across when the solar panels are out.
GPS receivers are generally accurate within 15 meters. Other than investing in a receiver there are no fees or other equipment required to access the GPS signal. If very accurate readings are needed, Differential Global Position Systems (DGPS) will provide accuracy within three to five meters. The United States Coast Guard operates the most popular DGPS.
Two power signals are transmitted and are referred to as L1 and L2. The L1 frequency is used for civilian purposes. These signals are relatively low power signals and travel by line of sight, so they can go through clouds, glass, and plastic, but not solid objects like buildings or mountains. In every transmission the satellite sends three types of information, its pseudorandom code, ephemeris data and almanac data. The pseudorandom code is an I.S. code that identifies which satellite the information is being sent from. Ephemeris data tells the receiver where the satellite should be at any time of the day, and almanac data sends information about the status of the satellite, the current date and the time. The almanac data is the part that is essential for determining the user’s position.
By: Chris Simons
Posts Tagged ‘Latitude And Longitude’
GPS And How It Works
January 17th, 2010Posted in Article
Tags: Altitude Backup Batteries Department Of Defense Global Positioning System Latitude And Longitude Latitude Longitude Proper Orbit Receivers Satellite Navigation System Satellites Small Rockets Solar Energy Solar Panels Solar Power Sunrise And Sunset Sunrise And Sunset Times Sunrise Sunset U S Department United States Department United States Department Of Defense
Marine GPS
December 21st, 2009
Marine GPS systems have become most boaters’ best friend. Depending on the reasons you need GPS Navigation, they can make it easy to find your way back to shore in unknown waters, navigate at night, and find large fish or avoid debris. History of Marine GPS: While it wasn’t that long ago that boaters or mariners consulted star charts and latitude/longitude numbers to figure out their way back to land, Marine GPS navigation changed the need for the inaccurate tracking system that some could not figure out. GPS or global positioning systems came into vogue after the launch of satellites that could send a signal of latitude and longitude locations to figure exactly where anything was back on Earth.
This principal has been used in fishing sonars and marine GPS systems, that use anywhere from 12 to 24 satellites to figure out positioning. Why Using Marine GPS Navigation Systems? The answer is simple, it is more accurate, less hassle than previous methods to find out where you are on the open sea or any body of water for that matter. Also, the most important reason is for safety. Not only can it keep you from getting lost, but you can chart ways around tropical storms at sea, or alternate routes, for whatever reason.
The Future of Marine GPS: These GPS systems continue to get more sophisticated, and come in hand-held models, all the way up to marine GPS navigation lap top computers. Depending on the functions you want, you can find a marine GPS that can do whatever you want it to, when it comes to navigation, topography in foreign water bodies, or take it hiking and camping with you, if it is a hand-held portable marine GPS. Some of the larger cruisers and yachts use it to “auto-pilot” a ship, and navigate back to port in the dark of night. Advice On
Buying a Marine GPS: Be sure and research all of the models and functions for the type of Marine GPS navigation you are going to be doing. In other words, certain factors, like whether it will be for river fishing or ocean adventures can determine the model you need and the number of functions. If you are looking for a fish finder, you may not need an expensive Marine GPS system with all kinds of bells and whistles. Commercial fishermen, for example, would need them to not only get them back to shore, avoid the paths of storms, and find fish, but might need alarms for shallow reefs or other alarms where a normal recreational fisherman might not need these features.
Marine GPS navigation systems have gotten to be almost a requirement for all types of water navigation, and finding a marine GPS unit is easy at retailers, but especially online, where the choices are unlimited. As more manufacturers have gotten into the GPS systems, even cell phones are GPS capable now. It’s all a matter of the number of functions you need for what you are going to be doing, when it comes to marine GPS navigation.
By: Alexis Kenne
Posted in Article
Tags: Alternate Routes Auto Pilot Global Positioning Systems Gps Marine Gps Navigation Systems Gps Systems Lap Top Computers Latitude And Longitude Latitude And Longitude Locations Latitude Longitude Launch Longitude Numbers Marine Gps Ocean Adventures Open Sea River Fishing Sonars Star Charts Storms At Sea Tropical Storms
GPS Tracking Software
November 25th, 2009
GPS tracking software is basically what makes GPS tracking devices work. This type of software enables a tracking device to transmit a signal which will be sent to satellites set up in space. The space satellites, in return, narrow down the devices geographic location. The location information returned is usually in latitude and longitude, which is then converted by a decoder into a recognizable address.
GPS tracking software was first used by the American Department of Defense, originally using 21 satellites and 3 replacement satellites. The software was primarily made for aviation, nautical navigation and land navigation. The GPS tracking software is a very intelligent system. The GPS satellites set up in orbit, transmits signals that track the exact location of a GPS receiver, be it a vehicle, mobile phone, or other forms of transportation or tracking devices. Now, the satellites have increased to 30 resulting to a wider range of GPS locations. However a GPS tracking software may also locate vehicles or persons that are not in possession of a GPS receiver. To quickly obtain a location, it will just need an unobstructed view of the satellites.
GPS was originally named NAVSTAR which stands for Navigation System for Timing and Ranging, now we have come to know it as GPS or Global Positioning system. The GPS tracking software has been very helpful in the field of navigation, as traveling in unchartered territories have not been easy since especially during bad weathers. As such, the GPS tracking software was built primarily for traveling in unknown routes, indicating the exact location of a moving vehicle in order to calculate what routes should be taken to assist it in reaching its prospective destinations.
The tracking software is also what enables huge delivery trucks in the U.S. to know their locations and inform their base headquarters of where they are. The tracking software allows this because the user can interact with the tracking unit in several ways. Through the GPS tracking software, a two-way communication between the truck driver and base headquarters can be done, in order to check on the status of the delivery truck on its way to its target destination.
Technology has once again proven that there are more inventions to be made in order to make our travels more safe and precise. With the vast sea and land with which seafarers and land farers must travel, the GPS tracking software is indeed the perfect tool to help them assess their movement, whether they are traveling in sky or water, or land. The best thing which anybody can say about having the GPS software is that for as long as there is no obstruction of the satellite signals, you can determine where you are and where you should be heading. However, should you be in the middle of a forest, then it will cause a bit of a problem for tracking your location with a GPS.
By: Jim Kesel
Posted in Article
Tags: Base Headquarters Delivery Trucks Exact Location Forms Of Transportation Geographic Location Global Positioning System Gps Locations Gps Receiver Gps Satellites Intelligent System Land Navigation Latitude And Longitude Nautical Navigation Navstar Software Gps Space Satellites Tracking Software Unchartered Territories Unobstructed View Weathers
