GPS - More than Just a Navigation Tool

What is the economic value of GPS today? In his book, Pinpoint, Greg Milner answers that with these outrageous lines:

“Placing an economic value on GPS has become nearly as impossible as pegging the value of other utilities. How much money do electricity and telephones generate?”

C’mon, I thought. Those are essentials, GPS is just a convenience. Milner went on to show how little I knew about the uses of GPS...

 

Heard of precision agriculture? Nope? When farmers plough their fields, the result is obviously not flat. That unevenness leads to an uneven distribution of water via irrigation. So they tried this experiment in India’s own UP: a two-acre farm was split in 2 halves, one ploughed by ox, the other by a small precision leveller using GPS (see how that works? If the land is uneven, different parts of it will get the GPS signal at slightly different times, since one part is a bit “up” and the other a bit “low”. The precision leveller, er, levels this by using GPS signals to “measure” and then evening out the difference). The difference in yields of the two sides of the farm? A whopping 4 times. No wonder then that precision agriculture is so important (for some crops) in the richer countries.

 

Transportation. Flights at the busiest airports used to maintain a safe distance decided by human ATC’s (air traffic controllers). They move in steps: fly a certain distance, drop a certain height, repeat until you land. And then GPS happened:

“It allows crowded airspace to be used more efficiently.”

Less fuel wastage, more flights handled, and “these little changes add up”. Landing in certain kinds of weather is now possible thanks to GPS, landing at certain airports a lot less riskier. On land, GPS enables tracking of trucks and deliveries. Drones are the next field that’s starting to open up thanks to GPS, and who knows what benefits (and yes, dangers too) that could lead to?

 

Then there’s GPS in its role as the time-keeper:

“As a timekeeper, GPS is impeccable – always available, always accurate, always free.”

We want our electrical grids to be smart: if one part goes down, divert flow immediately to avoid overloading. To do that, yes, different points on the grid need to send signals to some central node(s). But how would a central node make sense of the signals if everyone’s clock is even slightly different? Ergo, all the clocks on the grid must be synchronized with GPS time.

 

We tend to think positions on earth are fixed. Remember the plate tectonics theory, the one that says the earth has multiple plates which move and bump into each other? When the plates move, the ground moves, with that the GPS receivers on the ground move, something that can now be detected since the receiver would receive the signal at a slightly different time than earlier. Sound interesting but only of academic interest? Then consider that this same receiver can help detect earthquakes too. And tell how much the earth moved both horizontally and vertically and in how much time during that earthquake. How useful is that data when designing buildings and bridges in earthquake prone areas? And yes, they send signals to key infrastructure elements like power grids to shut down immediately to avoid fires during a big earthquake.

 

How fast is the snow melting at the poles? Put a GPS receiver, and its vertical position would change as the ice melts or accumulates, something that can be measured thanks to the change in time to receive the GPS signal.

 

With so many uses, I finally got why so many countries are trying to build their own GPS satellite systems. The Russians have it already. The EU, China, Japan and India are building theirs, bit by bit, so no, they’re not fully functional yet. Can you really blame all these countries for saying something this important can’t be left to the continuing goodwill of the Americans alone?