Thursday, May 12, 2016

What IS GPS, exactly... and what can it do for ME?

GPS is a modern convenience that is integrated into much of our daily lives.  While I am fairly certain that your toaster and refrigerator are not GPS enabled (yet), your cell phone, your tablet, your car... all of these and more are designed to operate with GPS and be more useful for the consumer.

GPS (Global Positioning System) is an outgrowth of a Department of Defense program to develop precision navigation.  It currently is made up of 24 satellites in orbit that really function as a series of ultra precise timers that constantly broadcast precise time signals, along with station ID.  Your receiver needs to "see" 3 GPS satellites to get a fix on your position.  The principle is that the time difference of arrival (TDOA) between the signals allows the GPS device to triangulate and give your location as a discrete spot on the earth.  You can really get into the weeds at if you are so inclined.  The more satellites that your receiver "sees", the more precise your location becomes.

GPS in your phone allows a host of functions.  It allows enhanced 911 tracking. It provides location data for your searches (where is the nearest gas station?), enables map data and embeds geo data on all your photos.  This file format is called EXIF data.  All phones since 2014 embed EXIF data.  When you post photos from your phone, you may want to put it into "paint" and change the file format.  This strips out the EXIF data, so you maintain a bit of your privacy that way.  Nobody needs to see a 10 digit grid coordinate for your latest cat picture.  Not even cute ones like this:

Can't recall where I found this, the watermark is too indistinct.  Can anyone help ID source?
The EXIF data that you have is not readily apparent.  You can use online sites like or are decent places to started on this for yourself.

GPS also is very useful for the outdoorsman as well as people interested in tracking their assets.  The current crop of hand held GPS units are an amazing collection of functionality at a variety of price points.    

Most cars can be found with some variant of that system.  However, our dependence on GPS to tell us how to get from A to B has rendered us dependent upon it like few other modern conveniences.  Our attention spans, our ability to spatially relate all get truncated by the modern convenience of technology.  Whatever you do, realize that GPS can never replace maps and a sense of direction.

The Garmin eTrex 20x is a civilian evolution of the personal GPS I carried on deployments.  This version has a lot more memory, a better color display and is GLONASS enabled.  GLONASS is the Russian equivalent to GPS and has some slightly different specifications.  Devices such as this are potentially life saving and need to be cared for.  At this point of design evolution, I just don't know what else they can pack into the form factor.  It is just that good.

An additional use of GPS is in asset tracking.  In researching this, I found a system that installs into cars and other high value assets that you want to know where they are. This enables users to track location, speed and a number of other parameters.

The website has an informative installation video... it looks reasonably straightforward to do.  You need nothing else, you get billed on a 3 month billing cycle for the level of service you choose.  Looking at a number of systems, this looks like the best deal for overall utility, ease if installation and customer service.  There is a definite correlation between price and what you get.  At about the $30 price point, there are some sketchy products out there that appear to involve a LOT more user integration.  As they say, "ain't nobody got time for that!"

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