A Greenland Story At Sea - Our Blog
A Greenland Story Blog
Tue 14 May 2019 15:07
A Greenland Story Satellite Blog
This is our first blog post delivered through our satellite phone connection. We’ll keep this short and sweet.
We will be using this blog to provide updates once we head off across the Atlantic. From this link you will be able to track our current position and see a breadcrumb trail of our route so far. For us to send this blog post we tap into Iridium satellite network, the constellation consists of 66 active satellites in orbit, required for global coverage, and additional spare satellites to serve in case of failure. They are continuously passing overhead, or more like we are continually spinning within the network. The constellation is actually owned by a publically traded US corporation called Iridium Communications, let’s hope they stay afloat!
For me to do a blog post I simply send an email and it appears on our personal blog page. The emails themselves are pretty cheap but the images, like the one of the satellites above, can end up costing a lot if you are not careful! So all images and videos are compressed right down, image quality definitely takes hit but less of a hit on the wallet.
To call any phone costs around €1.30/min. However, to create a connection in order to send an email is charged the same as a phone call. Considering that the data speed of the Iridium connection is 2.4kb/sec, in theory after I compressed the image above to 7.7kb that costs me roughly 7 cent (in theory....). It’ll end up being a bit more than this but not bad all the same!
This is all very old technology, we are essentially managing to use this tech for something that it wasn’t originally designed to do. We use this to get our weather as we cross the Atlantic and while we’re away from any other type of signal. This is standard for anyone doing ocean passages but I found it pretty interesting the first time I heard about it.
To get our weather we simply send an email to an automated service asking in the subject line for the type of weather data and the patch of ocean we are interested in, using a grid of latitude and longitude. Their algorithms automatically ping back a file of One’s & Zero’s in a matter of seconds, yeee old binary code. This is what’s called a GRIB file, General Regularly-distributed Information in Binary form. We then use a different program to interpret the code and we get something like the image below. For the image below I used a program called XyGrib which gives a nice visual interface. The bristle chart below shows wind strength and direction, usually we’d include a more parameters, pressure, wave height etc
GPS Position Tracking
Adding our coordinates, for example,