Everyone makes mistakes. And we’ve all gotten lost. Back in the day, it used to be that Mom had a huge, unfolded, small-print map on her lap sitting in the passenger seat, and Dad impatiently asking for directions while motoring along. Occasionally that caused many turnarounds and sometimes, tirades. And navigating at night was literally a nightmare.
When global positioning system units (GPS) first came out, the costs were prohibitive and only the richer among us could afford them. That was then, but today, GPS units are much more affordable—$100-$600—about what you’d pay for a high-end compass. But what is GPS, how does it work, and who owns it?
Maps versus GPS
Most older road maps are referred to as “planimetric” and that means they read different areas as flat. Generally, there was no designation for topography on a plain map—you couldn’t figure out the type of landscape that featured hills, valleys and mountains. Most modern maps today are topographical, which means they are made from aerial photographs and give a better picture of the land with flowing curves. Usually it is shown in the way of scales for elevation. There will always be a key and in American maps, for example, one unit on the map equals 250,000 units on the ground; and there are degrees of latitude and longitude—these are lines that run either parallel to the equator (latitude), or north-south (longitude), and intersect at the poles.
GPS (Global Positioning System)
GPS receivers are navigational items that use outer space for directional details. Twenty-four satellites (and some in reserve) orbit the Earth and transmit precise time (via an atomic clock), and pinpoint positioning information. The 3,000-to-4,000-pound solar-powered satellites circle the globe (at about 12,000 miles or 19,300 km), making two complete rotations every day.
How It Works
To calculate location, you need a GPS device and a clear sky. Your receiver will listen and try to find at least four satellites directly above you and determine a range. Those ranges use known locations and use some mathematical calculations called trilateration to figure out where that GPS receiver down below is. It can also provide the altitude, speed and direction you’re traveling. And, it can tell you how long you’ve traveled and give you an estimation of arrival (ETA) if you maintain your current speed. Wow, did you know that GPS can also tell when tectonic earth plates are shifting apart?!
Who Did It?
The United States Department of Defense placed a system of satellites in orbit around Earth, and other countries have similar systems such as Russia’s GLONASS, the European Galileo System, and Japan’s Quasi-Zenith Satellite System. The U.S. GPS is operated and maintained by the U.S. Air Force but there is lots of interoperability with other countries. Under good weather conditions, GPS receivers can pick up signals—radio frequency broadcasts traveling at the speed of light—to provide the user’s geographic position and altitude to within about 50 feet (15 meters).
Today, GPS is a critical part of the planet’s infrastructure, and the backbone of civil, economic, and defense activity everywhere. Military jamming prevents anything that unduly interrupts or interferes with its transmission too. GPS helps aviators find the most accurate locations and helps to save fuel; it guides ships and cargo and guides them in and out of harbors around the globe.
Financial systems and banking use GPS for accurate time stamps in nanoseconds, with which to conduct business. It is also utilized in precision agriculture to increase crop yield, and forecasters use GPS to predict weather patterns, find clouds, and protect people from weather-related natural disasters and to point out emergencies. M-Code, a special channel, enhances military operations. GPS is also implied in fishery management, mining and mapping. Of course, your smartphone uses it to connect you to family and friends.
It is paid for by the citizens of the United States and its taxpayers. GPS is protected: “The U.S. government works to minimize human sources of GPS interference through spectrum regulations (domestic and international), interference detection and mitigation efforts, and law enforcement.” It grants access to foreign nations with a renewable licensing waiver.
Wrong or Missing Information?
For incorrect or missing information, the government says that the problem is in the mapping software used by the devices or apps that are offered in the private sector by such businesses like Google, Apple, and other similar entities. GPS satellites are simply beacons like lighthouses, that a device uses to calculate its own latitude and longitude. The satellites do not transmit any mapping information.
So, to correct mapping errors in consumer devices or apps, there are links that will help you report them to the responsible parties (See: References). You can also report outages, service and status reports there.
Caveat for Travelers
If you intend to rely on GPS and are doing serious mountaineering, deep woods camping or any other wilderness navigation, you should learn how to read maps, be familiar with topography, and know how to use a compass as well.
A 38-year old Texas man got lost recently while hiking a remote mountainous area near Mena, Arkansas, and searchers looked for him for nearly a week. The sheriff’s office described the location as a “remote and rugged mountainous area,” and said that it’s common for hikers to get lost but that they are usually found within a few hours. According to the United States Department of Agriculture’s website, trails in that particular area “are not marked or signed” and hikers should take a map, compass, GPS device—or all of these—while exploring.
Burns, Bob & Mike Burns. Wilderness Navigation: Finding Your Way Using Map, Compass, Altimeter & GPS. Seattle: Mountaineer Books, 2015. Book.
Jacobson, Cliff. Basic Illustrated: Map and Compass. Helena, Montana: Falcon Guides Rowman & Littlefield, 2008. Book.
Photo courtesy of Pixabay