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DIY Satellite Tracking

Soulskill posted about 9 months ago | from the brought-to-you-by-hillbillies dept.

Space 30

Travis Goodspeed has authored a blog post detailing his method of tracking low-earth-orbit satellites. Starting with an old Felcom 82B dish made for use on maritime vessels, he added motors to move it around and a webcam-based homemade calibration system. "For handling the radio input and controlling the motors, I have a BeagleBone wired into a USB hub. These are all mounted on the trunk of the assembly inside of the radome, sending data back to a server indoors. ... In order to operate the dish, I wanted both a flashy GUI and concise scripting, but scripting was the higher priority. Toward that end, I constructed the software as a series of daemons that communicate through a PostgreSQL database on a server inside the house. For example, I can run SELECT * FROM sats WHERE el>0 to select the names and positions of all currently tracked satellites that are above the horizon. To begin tracking the International Space Station if it is in view, I run UPDATE target SET name='ISS';. For predicting satellite locations, I wrote a quick daemon using PyEphem that fetches satellite catalog data from CelesTrak. These positions are held in a database, with duplicates filtered out and positions constantly updated. PyEphem is sophisticated enough to predict in any number of formats, so it's easy to track many of the brighter stars as well as planets and deep-space probes, such as Voyagers 1 and 2."

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30 comments

Ok, maybe (3, Insightful)

Brett Buck (811747) | about 9 months ago | (#44367845)

Perhaps you can take and antenna and point it where you think Voyager might be with this sort of equipment. I am extremely skeptical that you can "track" it, that is, lock on to the carrier and then follow it. I bet you can't see the carrier at all, much less see the data.

     

Re:Ok, maybe (2)

Edis Krad (1003934) | about 9 months ago | (#44367895)

Maybe you should read the part where it says "low earth orbit"

Re:Ok, maybe (2)

batkiwi (137781) | about 9 months ago | (#44367907)

From the summary:

"so it's easy to track many of the brighter stars as well as planets and deep-space probes, such as Voyagers 1 and 2."

Re:Ok, maybe (4, Interesting)

Anonymous Coward | about 9 months ago | (#44367927)

Maybe "low" is relative... ;)

Re:Ok, maybe (5, Interesting)

hairyfeet (841228) | about 9 months ago | (#44368185)

I have a better question....why? Why would you go to this much trouble when you can use the free Stellarium [stellarium.org] and know where pretty much everything visible (and not visible unless you have a big ass telescope) and just call it a day? It can even control a telescope for you, just slap it on a netbook, wire it to the telescope and there ya go, easy peasy.

Who knows, maybe the guy didn't have anything better to do with his time but for everybody else you can do the same thing by just installing Stellarium and the extra chart packs. Hell if something you want to track isn't in any of their charts just tell 'em on the forums and i bet it'll be whipped off in no time at all, they just love adding more objects to the packs.

Re:Ok, maybe (1)

plover (150551) | about 9 months ago | (#44374165)

I have a better question....why? Why would you go to this much trouble when you can use the free Stellarium [stellarium.org] and know where pretty much everything visible (and not visible unless you have a big ass telescope) and just call it a day? It can even control a telescope for you, just slap it on a netbook, wire it to the telescope and there ya go, easy peasy.

Aside from the fact that PyEphem is probably the most ridiculously thorough ephemeris calculator available, and is an optimal tool when you are pointing one piece of equipment at one single target?

I know, let's check with Stellarium's own documentation [stellarium.org] on the subject:

"As of the current version, this plug-in doesn't allow satellite tracking, and is not very suitable for Moon or planetary observations."

I noticed a distinct lack of both easy and peasy in that statement. Does that answer your question of "why?"

Re:Ok, maybe (0)

Anonymous Coward | about 9 months ago | (#44379169)

OR http://gpredict.oz9aec.net/

Re:Ok, maybe (3, Insightful)

Ozoner (1406169) | about 9 months ago | (#44368027)

The article says right there in the heading ".. so it's easy to track many of the brighter stars as well as planets and deep-space probes, such as Voyagers 1 and 2"

Also there's a big difference between tracking and locking-on. Most big systems (eg NASA) simply track the target (based on precise ephemerals) because extracting the signal from the noise (post processing) takes far to long for locking-on to be practical.

Plus the beam-width of even a huge dish is far to wide to allow locking-on to be of much advantage. You can nod the dish a little and extract revised ephemerals after the event, but that's about all.

Re:Ok, maybe (1)

Flere Imsaho (786612) | about 8 months ago | (#44375597)

Actually, if you'd read TFA you'd have come across the text saying "In the screenshot above, the dish is aimed at GOES 3 and has just been ordered to aim at Voyager 1"

So let me get this straight. You've just publicly called this guy a liar, based on what - did the Force tell you he's full of shit? You bet he can't see the carrier at all? OK, email the guy and make a wager - put your money where your cynical mouth is.

This guy did something geeky and cool. It's not a new idea, but he's been good enough to blog some details of his interesting implementation that expands on what others have done before, only to have some asshole on /. call BS with zero justification. How the fuck did a snarky, dismissive post like this get modded up?

This is news? (4, Informative)

Ozoner (1406169) | about 9 months ago | (#44367971)

Amateur Radio operators have been automatically tracking satellites for decades and the tracking ephemeral's have been published forever.

Searching Google for "amateur satellite tracking" gets around 10 pages of hits.

Never mind. This is Slash Dot...

Re:This is news? (4, Insightful)

Anonymous Coward | about 9 months ago | (#44368097)

This isn't as much tracking them in the sense of figuring out where they are, but rather tracking them by controlling a dish, which is way cooler.

Re:This is news? (1)

Ozoner (1406169) | about 9 months ago | (#44368379)

> This isn't as much tracking them in the sense of figuring out where they are, but rather tracking them by controlling a dish.

Idiot. Of course the Hams are automatically steering their Satellite dishes. What on earth do you think they are doing?

It's tragic how some computer geeks live in a bubble hermetically sealed from the rest of the scientific world.

Re:This is news? (1, Funny)

Zynder (2773551) | about 9 months ago | (#44368103)

You got that wrong. You should have typed:

THIS IS SLASHDOT! Followed by a swift kick to the groin.

Reads like TDWTF material... (3, Insightful)

tibit (1762298) | about 9 months ago | (#44368037)

Using an SQL database as means of interprocess communication, wow.

Re:Reads like TDWTF material... (3, Interesting)

Greyfox (87712) | about 9 months ago | (#44368265)

Hmm. I didn't put a whole lot of effort into mine. I roll a TCP socket server that pretends to be a HTTP daemon and returns a KML file to Google Earth through a network link. Initially it was set up to read a data file with an ephemeris table for a satellite in it and plot a chunk of the satellite's orbit and its current location as a placemark. I'd just feed two or three interesting satellites worth of interesting data into it, running each one on a separate port.

Lately I've been using the same coordinates library to generate static KML files of GPS tracks in Google Earth. These files don't have the same realtime interest that the satellite tracking one does, since the GPS tracks are being gathered earlier and being batched processed. I have several C++ libraries up on Github, [github.com] if you're curious.

Re:Reads like TDWTF material... (1)

K. S. Kyosuke (729550) | about 9 months ago | (#44368541)

If the stream of data is slow enough... Such servers as Firebird can post update notifications to interested clients, for example, so it's not like you have to poll for the changes or something.

Re:Reads like TDWTF material... (0)

Anonymous Coward | about 9 months ago | (#44368959)

Using an SQL database as means of interprocess communication, wow.

That's nothing: at my last company we used to use NNTP servers to keep state of the distributed software builds for products that occurred nightly.

Re:Reads like TDWTF material... (1)

Flere Imsaho (786612) | about 8 months ago | (#44375619)

Then drop him a line and collaborate on something that is "better". It works for him, so what's the big deal?
Honestly, I'm having a hard time getting the nerd-hate this article is garnering.

Re:Reads like TDWTF material... (1)

tibit (1762298) | about 9 months ago | (#44379905)

I know the value of a hack that works, but there's plenty of such hacks that are TDWTF material at the same time. No hate implied.

Re:Reads like TDWTF material... (1)

Flere Imsaho (786612) | about 9 months ago | (#44385809)

Cool - sorry I took your post the wrong way - I was a little pissed at the level of meh this story was generating...

Thirty years ago... (4, Interesting)

ctrl-alt-canc (977108) | about 9 months ago | (#44368479)

,,,I tracked NOAA and OSCAR satellites using a polar Earth map upon which I superimposed a orbit-shaped transparent ruler. I then used NASA data, Kepler's equations and a desk calculator to compute the right ascension of the orbits that crossed my reception zone, and I set the ruler accordingly. While I was receiving satellite data I had to read on the ruler the satellite position and move my antennas, while another ruler gave me the amount of Doppler correction. Doing all these tasks alltogether was messy, but it was one of the funniest and more rewarding things I ever did when I was involved with ham radio. I don't think that if I had a computer to automate everything, I would have enjoyed this that much...

Re:Thirty years ago... (3, Interesting)

nojayuk (567177) | about 9 months ago | (#44369001)

I worked with the OSCAR Euro command people for a while in the early 80s at the University of Surrey. We had an ex-Navy AA radar X-Y director head on the roof of the building with some Yagis strapped to it to track the satellites and a microcomputer to do the tracking for us as well as sending control commands to the OSCARs as they went by.

The guy in charge was someone you might have heard of, a Ph. D. student name of Martin Sweeting who was busy designing and building cheap satellites; his thesis project was something called UOSAT-1.

And then I'll takeover the world ! (4, Funny)

ze_jua (910531) | about 9 months ago | (#44368537)

UPDATE target SET name='ISS'

It sounds like a quote of any James Bond vilain :)

Re:And then I'll takeover the world ! (0)

Anonymous Coward | about 9 months ago | (#44370355)

Wait until he "updates" his dish with a frikkin' laser.

The Sheer NUMBER of birds... (0)

Anonymous Coward | about 9 months ago | (#44369867)

I bet a lot of people are like I was, had no Idea how many Satellites and Space Junk there are going around.

I thought there was like oh lets say 30-50 Ya know MOtorola, Mitsubishi, AT&T, and what's the rocket company lockheed?? with it's ring around the Earth, for all the AT&T freq's. BUt no, there's hell of crap up there from not only just the US SO MANY OBJECTS to track, that if I try to load them and animate it bogs the machine down.

There are a LOT more satellites up there than most think. I have a registered copy of Earth Browser, it's where I learned there is a LOT more up there than I thought.

COdeZ 010001110
100101101110010011001010

110110001101100

011011010010

000001
00001 0011010
0101110100

01100011011010000110
01010111101000100001

Falling over dead now (0)

Anonymous Coward | about 9 months ago | (#44370937)

A useful, technical, fun Slashdot Article?? Holy God..

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