![]() If your target does more cleanup than just setting a noise floor and spitting things back out, you'll need to know that information as well. There are different variations of protocol, polarisation, modulation ( QAM is a good one to understand), etc. They receive a signal and they transmit that signal back. Some satellites are very simple, particularly amateur radio satellites. Being nicked just because you let strangers hear you might have some costs associated. It also means that it will be harder for somebody to hunt you down. It will keep your signal where you want it and limit the possibility of interference from or with other things using the same frequency. Just because your spot messenger or GPS doesn't have one doesn't mean you shouldn't use one if you can. Antenna design can be learned from amateur radio books on the topic.īefore someone chimes in and says, "You don't NEED a directional antenna and tracking motor," that's true. is wasted energy, so you will want an appropriately-sized high-gain antenna. Anything sent off to the sides, earth, etc. Because your signal has a lot of travel in its future and your target is small, your goal is to direct as much power in one direction as possible. ![]() The ubiquitous (in the United States) DirecTV / Dish Network antennas are usually on the higher end (smaller wavelength) of the spectrum. Most satellites operate in the microwave spectrum. Satellites operate on different frequencies, and the antenna used has to be sized to the frequency of the satellite. There are websites all over the place for this, and they often end up with military / disavowed satellites listed as people will track them with a telescope and then wonder why that one isn't listed yet. The satellite will come into view at different elevations in the sky tracing different paths, so you'll need to know where it will be and how it will move in order to communicate.Ĭommunications satellites tend to either be geostationary or part of a cluster of many satellites such that one or more is always in view of at least one ground station and any other point on the planet. Other satellites have orbits that sending them in offset patterns around the world. Some satellites are geostationary, so they're easy. Then people come knocking on your door.įirst, you've got to have a target. Also, "birds" and airtime are expensive, so the civil liability if found can be bankrupting.Īs far as taking a satellite transponder over is concerned, security relies on rarity of attacks, detection, and triangulation of the signal source. Legally speaking, you will at a minimum foul the FCC or your national equivalent, by violating regulations on licensed broadcasting. Your equipment needs to put out the right frequency through a dish that is the right size. I suspect that most command sequences are unencrypted and rely on the fact that a MITM attack on something in space is fairly hard.įrequencies vary wildly from MHz to several tens of GHz. Because most satellite systems are custom, it is a real crapshoot what you see for commands and security. These are used to interpret instructions to boost back into orbit or at the end of life, de-orbit into a "graveyard" pattern (or right into the atmosphere itself). Many satellites also require command modules. If you know the location and input frequency, and you pump more effective radiated power than anybody else, you win. The signal that comes in on a transponder is cleaned, amplified, and retransmitted. The majority of satellite systems are simple repeaters. First, I learned a lot of my information from a combination of my amateur radio experience and an awesome talk I sat in at DEFCON 18.
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