Viswanathan K's Thoughts

The GPS system used in most places across the world is owned and operated by the US. Given how important GPS is, many countries have developed their own GPS systems so that they are not at the mercy of America turning it off at a time of conflict. This is why Russia, the EU and China developed their own GPS systems. While all those systems are global in the extent of their coverage, Japan created its own system with only Japan as the covered area. India’s GPS system is officially IRNSS (Indian Regional Navigation Satellite System) but more commonly it is called NavIC (Navigation with Indian Constellation). It was named so since it can also be pronounced as नाविक (sailor or navigator). Its coverage area is limited to India and a region extending 1,500 beyond its borders. (The plan is to eventually have global coverage). The seeds for this were sown in 1999, during the Kargil war, when the US refused to share GPS data for Kargil. The project was approved in 2006. The ubiquitous of GPS in...

In March, 2011, a Canadian couple drove towards Las Vegas using GPS for directions. They never got there. Instead, the man was found dead, and the woman barely alive. There’s a term for what had happened: “Death by GPS”. As Greg Milner explains in his book on GPS, Pinpoint : “It describes what happens when your GPS fails you, not by being wrong, exactly, but often by being too right … it takes you down roads which barely exist, or were used at one time and abandoned, or are not suitable for your car…”   Of course, literal deaths by GPS are very rare. But reaching the wrong place is not very uncommon. Like the Japanese tourists who drove into the Australian ocean. Or the Belgian woman who ended up in Croatia. How can these things happen? Can’t people realize something is off as they stray farther and farther?   Well, when you’re driving through places you have no idea about, you have no sense of where you are anyway. And thus alertness is not really an option: “GPS ...

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 signal...

Once we have GPS co-ordinates for every place, you know where every place is, right? Wrong, writes Greg Milner in his book, Pinpoint : “Those GPS coordinates do not mean much to us without a map on which to peg them.” Huh? The maps of the world, regional or global, are called Geographic Information Systems (GIS). Combining GPS with GIS is not one bit easy, rather it is a “creative merger of computer science, cartography, and database management! But why should that be the case?   Map making has historically involved a method calling triangulation. Like the name suggests, it involves measuring triangles and laying them next to each other. An alternate method is to find the latitude and longitude of a place using astronomy. Ideally, the triangulation and astronomical methods should match. Except they don’t. Why? Because the earth isn’t a perfectly shaped ellipsoid. Rather, as it is a “complicated potato shape”. Therefore, to make the two methods align: “The early land surve...

GPS. Something the US military created. And something that makes navigation via Google Maps possible. That’s how I thought of it. That’s so much the norm that Greg Milner writes in his book, Pinpoint : “In the age of GPS, we don’t require the environment to locate ourselves.” Who needs landmarks when you have GPS to tell you where you are?!   The idea of GPS was conceptualized when the Soviets launched the first satellite, Sputnik, in 1957. To prove they had really done it, the Russians put an on-board transmitter. Check the strength, movement and pattern of the signal, they said. It could only come from something in orbit. Two American scientists, William Guier and George Weiffenbach, flipped that point around and realized that the satellite could detect the position on land by the same principle. In theory.   To achieve it in practice, GPS needed multiple satellites. And to make GPS accurate at the level we take for granted, “the clocks cannot falter”: “A timin...

Once upon, people asked for directions. Today, the smartphone tells us the way. Yes, we should be thanking Google Maps, but have you ever given GPS a thought? The story behind GPS is a fascinating one, as described in Simon Winchester’s book, Exactly . In March, 1967, the (then young) author was in charge of lowering an oil rig at the right spot. He got it “about two hundred feet off the ideal”. But the feedback he received was, “It’s good enough”! Imagine trying to get anywhere today with that kind of inaccuracy in the system… The idea of GPS was conceptualized thanks to the launch of the first man-made satellite in space in 1957, Sputnik . The Soviets were aware that the world would dismiss it as just propaganda. So they decided to have a way to prove it from the get-go: “The device was continuously emitting radio signals from a tiny transmitter on board.” Check for yourself, the Soviets were saying. The pattern of the signal (its changing strength as it orbited etc) c...

Todd Humphreys gave this TED talk where he said that something happened on May 2 nd , 2000 that changed the world dramatically. No, not overnight; but within a decade as smartphones took over the world. So what was that event? “On that morning, U.S. President Bill Clinton ordered that a special switch be thrown in the orbiting satellites of the Global Positioning System. Instantaneously, every civilian GPS receiver around the globe went from errors the size of a football field to errors the size of a small room.” Pretty soon, GPS accuracy got even better: “With more base stations, more ground stations, better receivers and better algorithms, GPS can now not only tell you what street you are on, but what part of the street.” Fast forward to present day when GPS and Big Data come together. Recently, Google launched a new feature called Your Timeline . If you use Google Maps, the feature lets you “view the places you’ve been on a given day, month or year”. O...