

Show HN: Super Trunking Scanner - rachelbythebay
http://scanner.rachelbythebay.com/

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rachelbythebay
I got tired of missing things which were going on around me, and my scanner
was more annoying than helpful at times, so I threw a bunch of software (and a
bit of hardware) at the problem. Questions welcome!

~~~
CamperBob
Very cool. I'd put the demo on the front page, actually, so people don't even
have to hit the 'Demo' button to see the list construct itself.

Is this a Smartnet system? Are you running a wideband front end with a
dedicated DDC for each physical channel?

(I did something like this for the Seattle-area trunked radio system a few
years ago -- <http://www.ke5fx.com/equinox/equinox.html> \-- but users have to
download a dedicated Win32 client, and it only allows a single user to control
the hardware at any given time.)

~~~
rachelbythebay
Good idea on the demo thing there. I dropped the "possum" call into the top
page after watching a few hits come in and it got way more interesting in
terms of people checking stuff out. I'll find a way to make the whole thing
work without that extra click -- thanks!

The city is using a Smartnet system as far as I can tell, and I'm using a
software-defined radio system to pull in the whole band and then split off the
chunks I care about. I'm also decoding the control channel so we know which
talkgroup is responsible for a call, which frequency they're on, and all of
this.

Your approach sounds interesting, and I bet you could get a web frontend onto
it which would bring about more attention and cross-platform compatibility,
too! It's worth a thought if nothing else.

~~~
bdb
Ooh, neat. What kind of hardware are you using? (And are you using gnuradio?
Does the gr-smartnet module on CGRAN actually work?)

~~~
rachelbythebay
gnuradio + gr-smartnet does actually work, and it will decode a control
channel. I got it to give me usable data for both the city of Santa Clara
system and Alameda County.

There are a lot of little bits and pieces you have to smash together to wind
up with something like this, though. I wound up playing with a lot of programs
in this field before deciding to build this. Discriminator taps are fun!

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blantonl
Very interesting concept. What hardware are you using on the back end to
accomplish this?

~~~
rachelbythebay
If you mean the computers, I have a couple of boring x86_64 Linux boxes. If
you mean the radio stuff, I'm not quite ready to describe the "secret sauce"
just yet. When I am, I'll post something on my /w/ pages (URL in profile).

~~~
blantonl
Sounds good. I own and operate <http://www.radioreference.com> and we have a
large live audio streaming platform for scanners (2800+ feeds). Something like
what you've developed definitely interests me. Great work!

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willidiots
I've always thought this was a great idea. I've got this going along with
LiveATC for SJC and I feel omnipresent!

Edit: Feature request - the ability to filter out certain talkgroups. The
streets guys have verbal diarrhea.

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rachelbythebay
How does LiveATC handle multiple frequencies? Can you follow ground, approach,
departure and all of that at the same time? It seems like you'd need to do
that to deal with all of the handoffs.

For the talkgroup filtering: noted, thanks! It'll become even more important
when you want to switch other cities and agencies in and out. The other day
with that nutcase in San Jose, I really wished I could just add their special
channels to my personal feed. That's my next big hurdle to clear.

~~~
willidiots
LiveATC is just scanners plugged into streaming boxes - the freqs covered
depend on the feed.

For SJC there's 5 separate feeds - one for ground (4 freqs), two for approach
(2 freqs), one for departure (1 freq) and one for tower (1 freq). To listen to
the handoffs, you either have to stream them simultaneously or manually switch
between feeds.

There's no awesome queueing / playback feature like you've got - it'd be super
nice to have!

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pavel_lishin
> Would you like to know more?

Is this a Starship Troopers reference? Because kudos, if so.

~~~
rachelbythebay
It is! Good spotting.

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_phred
This is awesome. The water treatment guys are hilarious. Makes me want to get
my ham license so that I can start playing around with these kind of cool
softradios.

~~~
joshu
I don't think you need a HAM licence to get a trunking receiver.

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joshu
This is SERIOUSLY cool.

However: I really can't make out what people are saying on the radio. (Not
just this one, in general.) Am I alone?

