Let It Rain (Just Not over My Satellite Link)

Posted by Marko Đurić Monday, Jan 02, 2017
Satellite Communication Systems Literature

We have attended a great Satellite Communication Systems education held by professor Michel Bousquet from the Institut supérieur de l'aéronautique et de l'espace (eng. National Higher French Institute of Aeronautics and Space, or simply ISAE) that was held on SES premises in Betzdorf, Luxembourg. Although the education was highly technical, professor managed to squeeze everything in four busy days, without skipping chapters or taking any shortcuts.

You probably already know that Amphinicy is a software company. And you have probably heard that we write software that understands the satellite industry. But what does that mean?
Well, most of us are software engineers. We know a lot about programming languages, software design and UX. We like to fiddle with our code and fancy new frameworks in a never- ending quest of finding the best solution. And yes, that is usually enough to make good software. But in order to make great software, in addition to our code-monkey skills, we need a certain amount of knowledge of the business domain to understand the problem we are trying to solve.

To prove that we are not just making up slogans, some of us got a chance to attend a great Satellite Communication Systems education held by the professor mentioned above Michel Bousquet. 

The training started on Earth. At this point, we were just looking at the sky and figuring out what is above our heads. Then we climbed to an altitude of roughly 36000 kilometres, sometimes through heavy rain, and stopped a bit on the satellite itself. There we have learned what lies beneath all those shiny protective layers. After finding out that tube amplifiers are mostly used in satellite transponders, like a fine-tuned high-quality audio amplifier with all the warmth... well, we came back to Earth - to all the homes, schools, institutions, even to your satellite phones and GPS's.

Satellite dishes field

Great story aside, we didn't actually go to space, but the training materials had followed the same path. From ground stations and uplink antennas to satellites and back to downlink antennas on the ground. We listened about earth stations and terminals, various satellite orbits, and all the nifty details of link analysis, digital communications, satellite networking, multibeam & regenerative systems, communication payload, optical communications, high capacity satellites and much more.

For example, did you know that there are many different satellite orbits? Of course, the most popular one is the geostationary orbit in which satellites have a fixed position above a particular place on the equator. These types of satellites are ideal for television; you can simply point your antenna towards the satellite and count on it to always remain on the same spot. However, if you’re trying to cover areas at high latitude (most of Russia), geostationary satellites orbiting over the equator won’t be of much use. In that case, satellites in highly elliptical orbits (e.g. Molniya or Tundra orbits) could be a great fit.

Another thing worth mentioning is that building a satellite communications system requires taking rain very seriously. And not just rain - everything in the atmosphere, between the ground station and the satellite, will try to mess with the signal. This means there will always be some important decisions to make. What kind of antenna do I need? How big should it be? How strong does my amplifier need to be? These answers are not easy to provide, and they require a lot of math. It’s also interesting to see that bumping the availability from 99.9% (9 hours of downtime per year) to 99.99% (1 hour of downtime) might increase the cost of the overall solution by ten times or more.

After listening to all that, we can certainly say that we have only scratched the surface of the vast space of satellite communications on our daily jobs. This course gave us an excellent overview of the domain, and it’s already proving itself useful. At least now we can say, without any doubt, that our software actually understands the satellite industry. :)

The rockets in front of the classroom

This blog has been written in collaboration with Igor Šoš who also attended the education.

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