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So, I know, I get it that it seems impossible with the crazy, amazing technology that exists today that a GPS microchip hasn’t been invented yet. I mean GPS has been operational for 30 years…and microchips for animals have been around for 40 years. So what’s the hold-up people? Why the hell has no one invented this yet? Don’ they know it’s the answer to ending lost pets once and for all?? Well, like everything life, it’s not that simple. Let’s take a step back and look at the two technologies involved and then talk about what is going to be necessary for the two of them to get hitched.
There’s a ton of stuff to unpack here. GPS, microchips…and how they could (potentially) work together. Personally, 10 page long posts scare me, so I’m breaking this one into a series of three. Let’s start with the more complicated technology…GPS.
How does GPS work?
GPS stands for Global Positioning System. It’s a US government-owned satellite based system that provides folks with PNT – that’s positioning, navigation and timing – for free – it’s an open and it’s pretty darned dependable. The whole system is made up of three segments – Space (the actual satellites), Control (our Air Force that run the whole thing) and Users (that’s folks like you and me…and Penny). There is a LOT of stuff I could go into here, but I want to just hit the highlights for you. Warning: Geekiness & Geocaching references ahead. (For those non-geocaching Muggles out there, Geocaching is a fun international game that uses million dollar satellites to find Tupperware in the woods. It’s one of Penny’s and my favorite activities.)
Let’s talk about the SPACE part for just a bit – the government is committed to maintaining at least 24 operational GPS satellites at least 95% of the time (31 are actually in operation right now). These bad boys orbit the earth twice a day in MEO (that’ Medium Earth Orbit which is over 12K miles about sea level). 24 need to always be operational so that at anyone, at any time of day, from pretty much anywhere on the planet (which is filled with millions of geocaches ripe for the finding) will have a viewpoint of at least 4 of the satellites.
All 24 devices are constantly transmitting two low power radio signals (we use one, the government uses the other) with three pieces of data: a pseudorandom code, ephemeris data and almanac data. The pseudorandom code is basically just that just telling you which of the 24 satellites is sending the data. The ephemeris data is the data and time, as well as the “health” level of the particular satellite. And the almanac data is basically an exact location where that specific satellite is supposed to be in orbit at that given time. That’s all those satellites do, continually blip out those three data points to two specific radio frequencies.
Now…the CONTROL segment. It’s a world-wide operation, run by the US Air Force, that’s made up of fabulous technical folks that monitor everything. They make sure it’s all working properly, satellites in the right place and they make sure three data points from the satellites are actually getting transmitted. These guys and gals make sure that the system runs smoothly and that the huge ground antennas, monitoring stations and tracking stations are all working in concert so the satellites can tell us our GPS position so we can be the first to find the new Geocache that was just published in a nearby n before any other geocachers nab it.
That brings us to the USERS – you and me…and our pets. Now here’s the thing, the satellites in the sky aren’t actually having a conversation with us, and they don’t even know we exist– they are just constantly broadcasting those three data points. We humans (and dogs) have to be carrying tools that are not really “connecting with GPS satellites” – they’re just listening to the broadcast. The tools, those devices like our smartphones or a GPS dog collar – they’re called RECEIVERS. Our receivers listen to data transmitted from hopefully at least 4 of the satellites (you only really need 3, but the more, the better), calculate using triangulation to figure out our three-dimensional position in time and space so our device can tells us that we need to cross over two blocks to the north to that OTHER neighborhood park to find the cache.
SO, the satellites in SPACE send out data to a system CONTROLLED by our government to US so we can spend the weekend finding Tupperware in the woods.
I want to take just a minute to chat briefly about GPS accuracy – which will play a big part in the “why are there no GPS microchips yet” discussion. The satellites have a “”worst case’ pseudorange of 7.8 meters with 95% accuracy.” Meaning that with the distance & time it takes to travel from the satellite to the end user, the data generally accurate give or take 25 feet. Geez, that doesn’t seem so accurate, does it?
Never fear, the system’s accuracy is further augmented by a vast network of other systems of private and government satellites, antennas and transmitters to generally get us within hopefully a few yards of our intended piece of Tupperware. But that accuracy can be even more challenged on the receiver end –the accuracy of reception can be influenced by things like weather, atmospheric disturbances, big things in the sky blocking view (think skyscapers), or a big bolder in front of the tree under which the cache is hidden. Another big factor? The quality of the receiver. (That “quality of the receiver” will be super important later in the discussion, folks.) Not to mention a TON of other signals going out from our homes and business and cell towers. The more the “Internet of Things” grows, the more radio frequency signals (RF readings) are out in the air.
What I’m getting at here is that a LOT of RF readings are being received, interpreted, weeded out and then calculated by whatever device you are using to determine whether the cache is on the left or the right side of the path in the park. The receiver device’s job is a very complicated one that we take for granted with today’s amazing technology. Come on, admit it, how many of you have yelled at your smartphone because it took a full 10 seconds to re-calculate when you made a wrong turn, huh? And there are GPS receivers made for tracking things, including pets…but there’s more to them than you might realize, too. (check out the sidebar)
Now – one thing that is needed to make all three of these GPS system segments work in concert so that I can get to that cache before any other geocachers – power. Electricity. BATTERIES!! Think back to a time when your iPhone or Droid was navigating you somewhere and the battery drained quickly and the phone was kinda hot to the touch after a while…that’s a sign of how much power is being used to navigate. Even though it is a low-powered radio signal that is being transmitted by those satellites – the receiver has to be powered by a decent amount of electricity in order to take that jumble of RF signals out there and help us get to the exact location of the cache so we can nab the FTF swag (The “first to find” geocacher is often left a fun prize by the cache owner like a dollar bill or a collectible Geocoin – Woohoo!).
But before we talk about the potential energy source for GPS inside your pets, I think it’s time to switch gears and chat about microchips and how they work. So hop on over to Part II!