The following is a Plus Edition article written by and copyright by Dick Eastman.
My recent article at http://goo.gl/lbTj5 about defacing tombstones by attaching new objects with adhesives has generated a lot of comments about one thing I didn't expect: the use of GPS (Global Positioning System satellite navigation system) in a cell phone to determine the location of a tombstone. Some of the comments questioned the accuracy of cell phone devices; so, I decided to write a separate article to address those questions. I will divide this into three different points in time: what the cell phone accuracy was a few years ago, what it is today, and it what it might become in the near future.
Wikipedia states: "The Global Positioning System (GPS) is a space-based satellite navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. The system provides critical capabilities to military, civil and commercial users around the world. It is maintained by the United States Government and is freely accessible to anyone with a GPS receiver."
GPS receivers have been available to military and commercial users since the 1970s. By the 1990s prices were dropping, and the units then became popular with the general public. Nowadays, inexpensive GPS navigation receivers are commonly found in all sorts of automobiles, trucks, and, more recently, even inside the so-called "smartphones" that combine a cell phone with a handheld computer and camera and more inside a shirt-pocket-sized case. GPS receivers are used by millions, including truck drivers, bus drivers, fishermen, delivery truck drivers, and anyone else who simply wants easy-to-use guidance to find a place. In fact, many joggers purchase wristwatches that have built-in GPS receivers that will record the runner's distance traveled as well as the exact route.
I even use my iPhone's GPS receiver when riding my bicycle for exercise and enjoyment. A smartphone app shows exactly where I am at the moment, displays my speed, the average speed since I started the ride, the amount of elevation gained or lost, and an estimate of the number of calories burned. It tracks all this on a map displayed on the screen. At the end of the ride, I can even send a log file showing the details of the ride via email to myself or to a friend or even upload the log file to a web site. I can visit the web site later to view reports on my progress over the last few weeks or months, showing if I am getting enough exercise and burning enough calories or not. This app only costs $9.99 (plus the price of the smartphone, which I already owned) and is available for the iPhone, Android, and Windows Phone at http://b-icycle.com. Not a bad price for using all that technology, including satellites in outer space!
You can find hundreds of other uses for GPS receivers, including those built into smartphones. Genealogists have learned that GPS receivers are great for recording locations that are important to us. The first application that pops to mind is for recording the locations of tombstones so that we can find them again or, even more importantly, we can publish the locations on the web to aid others who might want to visit the same grave site in the future. GPS usage is not limited to tombstones, however. Genealogists also can record the exact locations of old homesteads, churches, schools, and other places that were important in the lives of our ancestors. Recording the exact location of a courthouse is also very useful when you are trying to find it in the midst of a busy city during rush hour. Indeed, GPS receivers (often built into a cell phone) have become standard tools for genealogists.
Early cell phones did not have built-in GPS receivers. In the early days (three or four years ago), the only way to find the location of a cell phone was by use of something called "cell tower triangulation." It was crude and could only pinpoint the cell phone's location within a mile or so. The cheaper cell phones of today are still limited to cell tower triangulation to identify a location but almost all the medium-priced to expensive cell phones in today's marketplace can provide much better accuracy.
Times have changed.
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