There's a little more insight in this link, where they discuss the joys of snooping the feeds from satellites. They can get a raw, unedited feed and see "behind the scenes". In the hacker culture, simply aquiring difficult to find information usually enough of a drive to get some amazing things done.
Thanks Caleb. I'm reminded now of how many times I've seen outtakes of famous people making bloopers on a live feed while waiting for a press conference to begin. I'm not sure you'd remember it, but, while waiting for a news conference at the height of the cold war, Ronald Reagan once "joked" that bombing of the Soviet Union would start in 15 minutes. Moscow was not amused; nor were US allies in Europe.
But is this rig designed to "listen in" or to simply monitor the orbits of satellites?
Thanks for this story. My brother built his own telescope at the telescope makers workshop and then voluteers at the local observatory during a public viewing hours; he's always checks for satelites, the International Space Station, space shuttles, and iridium flares so he can point them out. I bet this contraption would be popular where he volunteers. He might even make one. Thanks again.
There need not be a specific end application in mind when you start to do such things. Its totally plausible that people who are inquisitive and have time, do things like this. Sometimes other people can find an end application. History of tech shows it very clearly..
classic ex: Xerox engineers made first GUI and didnt know what to do with it. It took a Steve Jobs, to connect the dots between GUI and personal computing.
EEwiz: I like that explanation to "why:" that the thrill may be in simply exploring an option, with an end application to come later. And, yes, the way Steve Jobs applied the lessons of th GUI and mouse are good examples. Still, you gotta wonder how a guy working on his own is going to influence change on a larger scale, especially when satellite tracking is already something done very well on higher levels.
I don't see it myself, but could this technology be applied to a different field?
Like any hobby this has its points of pride. Often people brag about connecting to difficult or distant satellites. While his is receive-only, he has quite the display to show off. I imagine there's a certain thrill in being able to "see" these things that are often quite literally invisible to the lay-person. The more you can see, the more respect you get.
This is all conjecture based off of my familarity with other radio enthusiasts though.
Great article - i read through the build instructions but didn't see anything about the accuracy requirements for the application, but the fact that he chose a stepper motor leads me to think they were not that stringent, or possibly he has instituted some kind of microstepping scheme. Details, we want details!
I don't have any exact details on that, however, keep in mind that he started with a system designed for this purpose(fine tracking). There could be gearing in place or something to refine the movement.
The dish would have a beam width (for reception read a lobe width) of probably around half a degree. As long as your motor steps move the dish a fair bit less than that (say 0.1 degree or less) you should not have a problem.