Today is world tsunami awareness day! Taking this opportunity, I thought I will share with you some interesting technical stuff.
Friends, this is not a blog in the usual sense. It is a compilation of scientific applications of GPS in different fields. I have taken this information from the net but mainly from some documents published by Smithsonian Institution. I thought I must share this with you folks.
If you are scientific-minded, don’t miss the opportunity to view this site.
GPS is a commonly-understood acronym that stands for “Global Positioning System,” which in turn is an interconnected system of satellites and receivers that allows for the precise pinpointing of locations anywhere on or directly above the earth. These sorts of systems have become very popular for everyday navigation, and many cars come with receivers installed to help drivers find their way to their locations. Maps applications on many smartphones also provide this sort of turn-by-turn guidance to help people get on the right streets and take the proper exits. Beyond this more “standard” navigation, though, global positioning systems also have a significant role when it comes to navigation on the ocean, deep in the forest, and in other largely “uncharted” areas.
The current GPS is wholly owned by the United States, but they allow free usage of the same to everybody.
Several other countries and regions, in particular Russia, the European Union, and India, have or are in the process of creating their unique systems. It is to complement the US version but potentially also to augment it and protect local users in the event of failure or other disabling of the services.
The heart of the system relies on 24 satellites that orbit the planet twice per day. Devices that are equipped with GPS equipment receive transmissions from at least a few of the satellites and can discern exact positioning data. The first of these satellites was launched in 1974, and it wasn’t until 1994 that the 24th entered orbit. New satellites are periodically launched to replace ageing ones.
The discussion is going to be a bit technical, but I will try my best to make it in English instead of techy language.
I was surprised to find that GPS can be and is being used for some other applications too! It is nor surprising in the technological world. The human brain can find many different uses other than the intended usages.
GPS is being used to
- Analyse atmosphere
- Probe the snow
- Sense a sinking
- Monitoring the Volcano
I was also equally surprised to know these usages of GPS systems. I will briefly share how this is done.
Water vapour, electrically charged particles, and other factors can delay GPS signals travelling through the atmosphere, and that allows researchers to make new discoveries.
A group uses GPS to study the amount of water vapour in the atmosphere that is available to precipitate out as rain or snow. Researchers use these changes to calculate how much water is likely to fall from the sky in drenching downpours.
GPS signals are also affected when they travel through the electrically charged part of the upper atmosphere, known as the ionosphere. Scientists have used GPS data to track changes in the ionosphere as tsunamis race across the ocean below– The force of the tsunami produces changes in the atmosphere that ripple up to the ionosphere. These changes help in predicting details about tsunamis.
Probe the snow
A typical GPS receiver mostly picks up signals that are coming directly from GPS satellites overhead. But it also picks up signals that have bounced on the ground you’re walking on. It is then reflected up to your smartphone.
For many years, scientists had thought these reflected signals were nothing but messy interference of signals. Scientists started looking at the frequencies of the signals that reflected off the ground. Depending on how those combined with the signals that had arrived directly at the receiver. By studying these two signals, a scientist could deduce qualities of the surface that the echoes had bounced off.
Such a study allows scientists to learn about the ground beneath the GPS receiver. For instance, how much moisture the soil contains or how much snow has accumulated on the surface. The more snow falls on the ground, the shorter the distance between the echo and the receiver. The technique is beneficial in areas like Arctic and Antarctica, where having physical weather stations is not practical.
Sense a sinking
Scientists placed one GPS station on the concrete roof of a primary school. They set up a second station nearby, atop a rod hammered into a rice paddy. If the ground is sinking, then the second GPS station will look as if it is slowly emerging from the ground. And by measuring the GPS echoes beneath the stations, the scientists can measure factors; the factors as how much water is standing in the rice paddy during the rainy season.
Monitor a Volcano
Many volcano observatories, for example, have GPS receivers arrayed around the mountains they monitor, because when magma begins shifting underground that often causes the surface to shift as well. By monitoring how GPS stations around a volcano rise or sink over time, researchers can get a better idea about where molten rock is flowing.
Before the big eruption of the Kilauea volcano in Hawaii, researchers used GPS to understand which parts of the volcano were shifting most rapidly. Officials used that information to help decide which areas to evacuate residents from.
I hope you liked this compilation. The scientific theories behind these applications are too techy. Hence I have avoided using technical terms and tried to make it easy to understand.