HFU HF Underground
Technical Topics => SDR - Software Defined Radio => Topic started by: ChrisSmolinski on January 15, 2013, 0118 UTC
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Here's a screenshot of some decodes of ADS-B aircraft transponders using Dump1090, getting I/Q data from an RTL dongle via rtl_tcp:
(http://www.hfunderpants.com/mypics/Dump1090.jpg)
I'm going to try posting a description on the blog shortly.
The next step is to turn Dump1090 into a Cocoa app, with plotting.
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NICE!
I was playing with that last night. Saw the "interactive" option, but never bothered to actually try it.
That's a ton better than the non-interactive mode. Finally got a couple with a flight number. They must come in the packets and guessing the pilots probably program them in if they feel like it (have seen reports of interesting ACARS callsigns). I think the hex code & the tail number are in there more or less permanently.
BTW: Once the flight number is known, can track them at
http://flightaware.com
http://planefinder.net
http://www.flightradar24.com
The latter two also do ADS-B tracking. Non-ADS-B tracking is delayed about 5 minutes from the FAA data.
Seeing DAL264 on dump1090 and saw it on the PlaneFinder map. Unsurprisingly, the data was consistent.
DAL264 departed KMSP and enroute to Amsterdam. In a little while, it should be on HF. Wish I was on that flight.
Planefinder has a database where you can lookup the hex code and get the tail number.
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BTW: Once the flight number is known, can track them at
http://flightaware.com
http://planefinder.net
http://www.flightradar24.com
Coooooooooooool, thanks! ;D
Peace!
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I left it running overnight, and was pleasantly surprised to see everything was still running this morning, I had some issues with it locking up yesterday, but I think that was due to a poor soldering job on my part, the 5V line to the dongle wasn't a good connection.
How many of the planes do you observe with full data (position and speed)? Generally I'll see a few dozen planes total at a time, but only a handful (3 to 6 say) with all the data.
FWIW - For an antenna, I am using my mechanically challenged discone (it's missing a few elements). I also connected an old TV amp in line, and it seemed to boost the decode rate a little. I've also read that you should set the RTL gain to maximum with AGC off, I did that, and it also seemed to boost the decode rate a bit. I need to play around and make sure both are having a real effect.
I've seen plans for a J Pole antenna for 1090 MHz, but haven't built it, it requires either semi rigid or small diameter coax for a balun, neither of which I have. There's also a link to a pre-amp for 1090 MHz, using a transistor that seems to be obsolete, although there may be substitutes: http://www.lll.lu/~edward/edward/adsb/antenna/ADSBantenna.html
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Rat Shack sells copper clad RG-174 for their higher grade of patch cables,Chris. They come in various lengths out to about 6-8 feet. I've used them for all sorts of things.
BTW, nice choice of moderator.
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At any given time (in the evenings), I see 1 to 10 aircraft. I'm about 10 mi away from the major airport.
See a lot of zeros.
Some give their flight number
Some give their alt.
Some also give lat/long, track and/or speed.
A fraction give all of the info. Certainly see a lot of 0's for the data.
Interestingly, I now have one that has zero for the altitude (a4b15d).
After typing that up, now there are two more with zero altitude. And one of them is on a heading of 259 doing 422 kts.
Don't know if this thing has problems decoding or if the aircraft isn't sending all of the data. The default for dump1090 is max gain & no AGC.
I'm too far from the ground station (assuming its at KMSP) so I wonder if its giving useful data to fill in stuff so the a/c doesn't have to.
Seeing FDX320 from Memphis to Grand Forks at 38000', 453 kts, and a heading of 334 deg. Confirmed that with PlaneFinder.net. Lat/long had been 0 for a while on it, but they eventually filled in. And after that, it populated the flight #. Hope he has a little fun and tunes into Kenie (AA) on 365 kHz in Fargo.
Also seeing a couple of MN ANG C-130s... GOFER22 & GOFER03. Both of them have all zeroes.
Meanwhile, VIR20F (SFO-LHR) has all of the data and CKK234 (China Cargo Airlines, ORD-PUD)
For a brief moment, one aircraft was at 7375'. Looked at that number and though back to the last frequency Radio Croatia used to broadcast to us a couple of weeks ago. Miss them, a lot.
Still just using the little UHF magnetic antenna that came with the USB stick. Gets the job done for now and will be perfect when I zip by the airport one of the these days with the laptop and see if I can get any other data. Also need to find out were the ground stations are around here.
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This is a pretty cool idea:
http://www.sportys.com/PilotShop/product/17165
Could probably do that with an SDR to grab the ADS-B weather with an app on a computer that will then stream it via local wireless network (multicast), unicast or even on the Internet to other devices running another custom app.
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This is a pretty cool idea:
http://www.sportys.com/PilotShop/product/17165
Could probably do that with an SDR to grab the ADS-B weather with an app on a computer that will then stream it via local wireless network (multicast), unicast or even on the Internet to other devices running another custom app.
Yes it is. I am not sure if the UAT 978 MHz protocol is the same as ADS-B or not. I found some documentation on it but have not had the time to read through it yet: http://portal.aerocivil.gov.co/portal/pls/portal/!PORTAL.wwpob_page.show?_docname=8039112.PDF
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The first cut of the cocoa port of the ADS-B decoding app:
(http://www.hfunderpants.com/mypics/Cocoa1090.png)
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And now an iPad viewer also, it gets info from Cocoa1090 via UDP packets:
(http://www.hfunderpants.com/mypics/i1090.png)
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Tonight I've joined the ADS-B club too. Late last week I ordered two of the R820T units from NooElec. They arrived today. I got rtlsdr and dump1090 working together on Ubuntu 12.10 64-bit.
A rough outline is here:
http://www.hfunderground.com/wiki/RTL-SDR#Building_rtl-sdr_on_Ubuntu_12.10_64-bit
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Very nice Chris!
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A short update, my E4000 tuner based RTL dongle arrived today. It seems to work as well as, and perhaps slightly better than, the R820T tuner RTL for ADS-B reception (difficult to say for sure so far).
I needed a second antenna for it, so I decided to try a cheapo RCA amplified TV antenna, which is incapable of receiving any TV stations. It seems to work great on 1090 MHz for ADS-B, however, I am getting a much higher frames/second rate than with the discone attached to the R820T RTL. I need to swap antennas to see what happens.
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Interesting... I have an RCA amplified TV antenna as well, but never thought to try it here (in fact, forgot about the thing. My rabbit ears seem to work better).
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Some more work on i1090:
(http://www.hfunderpants.com/mypics/i1090_map.png)