Global Positioning System Locators; Electronic pathfinders for dummies

There was a time less than half a century ago when all navigators had to either depend on the ancient art of Dead Reckoning or a topographic map and a compass or, in the case of mariners, a chart, a sextant and, a compass to determine their position on the face of the Earth. But, even then, most fixes were merely close approximations given in degrees and minutes at best and thus, even for the best navigators, finding your way to your destination over long distances was as much art as it was science. However, thanks to the Defense Advanced Research Projects Agency (aka DARPA) and the U.S. Air force in conjunction with the U.S. Government, many people have grown up using Global Positioning System applications on their smart phones and/or dash mounted GPS units in their vehicles which literally provide the user with turn-by-turn instructions to arrive at any chosen destination without fail. In fact, this technology has become so prevalent in today’s world that mounted GPS locators are now available for vehicles, boats, and planes and, handheld units are available for hikers and explorers. Thus, considering that GPS locators are readily available for most any mode of transportation and, that they are relatively inexpensive, why would you not want to purchase one to guide you on your travels?

For your information, the Global Positioning System was developed by DARPA and deployed by the U.S. Department of Defense in 1973 for use by the United States Military but, it did not become fully operational until 1995 when the last of 27 GPS satellites was launched into orbit around the Earth. Even so, due to the potential value to both civil transportation and science, civilians were permitted access to the GPS system in the 1980s. However, both advances in technology and new demands placed on the then existing system led to efforts in 1988 to modernize the system but, it was not until 2000 that the U.S. Congress finally authorized the needed changes which, in turn, led to the next generation of GPS Block IIIA satellites and the next generation Operational Control System (OCX).

In addition, for those of you who are not familiar with the inner workings of the Global Positioning System, it is a space-based, radio-navigation, system owned by the United States government and operated by the United States Air Force and, it provides geolocation and time information to all GPS receivers anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites simultaneously. In fact, the Global Positioning System does not require the user to transmit any data and, it operates independently of telephone and internet services and thus, it is capable of providing critical, real-time, location information to military, civilian, and commercial users around the world and, it is accessible free of charge to anyone with a GPS receiver.

So, now that you understand what a GPS locator is, it is time to discuss how they work and why everyone who travels to distant destinations on either land or water should have a GPS locator along. Thus, the first thing that you need to understand is that although there are a total of 27 GPS satellites which all orbit the Earth twice per day, only 24 are in use at any given time while the other three serve as failsafes and thus, the system is always on and always provides the necessary number of signals to virtually any location on Earth. However, the U.S. Military does have the ability to selectively block the signal in any given location and thus, it may not be available to civilians in a time of war. However, provided that the signal is available, GPS locators use a process known as Trilateration which differs from the process of Triangulation because Triangulation determines a position by measuring the angles of the triangles formed between an observer and two known points whereas, Trilateration determines a position by measuring the distance from an observer to at least two known points. However, it should be noted that GPS locators use the signals broadcast from at least four orbiting satellites at any given time to determine a position by simultaneously measuring the amount of delay in receiving the signal from the satellites based upon their calculated position in their orbits at any given time of day. Consequently, as long as you have a clear enough line of sight to receive at least 4 out of 24 total signals from the GPS system, you GPS locator will be able to determine your location.

However, while simply knowing your Longitude and Latitude is sufficient for highly experienced mariners to navigate the world’s oceans, most navigators need a bit more detail than that because the surface of the ocean is relatively featureless while, the land features widely varied terrain; some which presents significant obstacles to travel. Therefore, GPS locator manufacturers have also included the ability to upload software such as topographic maps and/or nautical charts into the memories of their various GPS locators to provide users with a significant level of graphic detail about their location to make navigating to a specific destination much easier. Therefore, GPS locators designed for vehicle use usually have extensive street map data bases as well as traveler information such as restaurants, hotels, entertainment, and locals sights. Thus, with the push of a few buttons, you can locate any address you choose and receive turn-by-turn directions via electronic voice instruction as well as via a visual display to enable you to arrive at your destination without the anxiety of not knowing where you are or where you are going. But, if you are a boater instead, then there are also marine specific GPS locators in both mounted and handheld models who’s databases contain nautical charts which enable you easily determine your position when out on the water as well as providing a visual display of your course to your desired destination. On the other hand, if you are a hiker or an explorer, then there are also GPS locators that are designed especially for you because their databases contain copies of the world’s topographic maps and thus, they are capable of displaying your location in remote wilderness areas as well as the course you have traveled and the direction to your desired destination. Furthermore, GPS locators enable you to mark “waypoints” which is any point that is of interest to you and thus, simply by pushing a single button, you can record the location of any given point and then save it in the locator’s memory while also assigning it a unique name so that you can find it again if you want to. Plus, many units will enable you to connect your GPS locator to your computer in order to download the data stored in the locator’s memory as well to access the locator’s database in order to create pre-determined routes by establishing a series of waypoints that will enable you to avoid difficult terrain obstacles by traveling from waypoint to waypoint to eventually arrive at your destination. Therefore, Global Positioning System locators serve as simple, electronic, pathfinders for dummies!

Consequently, simply by having a GPS locator along with you when you travel, you can alleviate all of the stress that is inevitability experienced by the Human psyche when people don’t know where they are or what direction to travel in to arrive at their chosen destination. In fact, because modern GPS locators provide users with so much more than simply their longitude and latitude, drivers can choose destinations by address or type and then receive clear, simple-to-follow, turn-by-turn, directions to their chosen destination while, mariners can plot and follow a course with the ease of drivers and, outdoor adventurers can find their way in the wilderness regardless of how far into uncharted territory they may travel. Plus, with the ability to plot your desired course and destination prior to embarking combined with the ability to record your actual course and mark waypoints along the way regardless of whether you are driving, boating, paddling or, walking, Global Positioning System receivers are the best tools travelers have been presented with since the invention of the wheel! So, with such a handy and relatively inexpensive device readily available, why on Earth would you not want one?

Featured Image by locomomo, CC

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