Monitor Site for DC FD, EMS & City Services

[lukekb]

It put together a SDR system & website that lets you listen to all of the talkgroups on the DC FD, EMS & City Services trunking system. It monitors the SmartNet system at ~856MHz.

The site is at: http://openmhz.com

I have a writeup on it here: Using a HackRF to Capture an Entire Radio System — Luke Berndt

I want to try and make this as useful as possible to people. Let me know if you have ideas on what would make it better!

 

[jpryor]

Awesome, I have been on the lookout for an SDR based digital trunking receive all, log all, disseminate all solution. Very nice. Trying to get the auto play to work, I was thinking it would be click auto play and all new items play automatically, but that was not happening. But not sure if I have the right combination of the live, play and auto play toggles. Also using an iPad.

 

[lukekb]

Not working on iPad

Thanks for checking it out!
I just checked it out on my iPad and it doesn't look like Autoplay & Live is working. I does work on my laptop though. If you click on Live and Autoplay, it should playback new calls as they come in. You can filter it down to Dispatch or a different talk group if you just want to listen to that.

I will try to get it working on the iPad.

- Luke

 

[mk262]

Do you know if anyone has done this with a mirics dongle? They can do about 8mhz of spectrum at once, are relatively cheap and purchasable.

 

[dtscho]

This is awesome. This could help us identify many talkgroups from the services group. Would you consider adding unknown talkgroups? Then we could listen remotely and work on identifying them. Thanks.

Also, I'm unable to scroll down the talkgroups pop-up menu filter. I'm using Safari 7.0 on Mac.

Dave

 

[lukekb]

It should be pretty easy to do something similar with one of those dongles. I just check and the OsmoSDR drivers have beta support for the mirics, and that is the same driver I used.

Is there a good source for them? I didn't see much when I googled.

 

[mk262]

Sample store | MIRICS

 

[lukekb]

Talkgroups

This is awesome. This could help us identify many talkgroups from the services group. Would you consider adding unknown talkgroups? Then we could listen remotely and work on identifying them. Thanks.

Also, I'm unable to scroll down the talkgroups pop-up menu filter. I'm using Safari 7.0 on Mac.

Dave

Good to hear it is useful! I am just using it to track our local engine (#21)

It should display unknown talkgroups and just lists the talkgroup number. I am not sure if they show up on the statistics page though, which would be more useful ( http://www.openmhz.com/stats ) It does a DB query to build it and I will go check. This would probably be the best way to find unknown talkgroups and figure out what they are. It is a bit messed up now because it looks like DC switched to an alternate control channel and I didn't catch it.

Yea - I am having the same problem with the talkgroup pop-up menu filter. I gotta dig into the Bootstrap framework which does the UI. In the interim, the stats page lets you filter by a talkgroup. You can also edit the URL: http://www.openmhz.com/scanner/tg-1616

Just change the numbers at the end to a talkgroup num you want to filter for.

- Luke

 

[dtscho]

Thanks. I was able to ID a few unknowns this afternoon. Changing the URL for different talkgroups did the trick.

Dave

 

[dtscho]

If it's not too much trouble, it would also be handy to have the date on each transmission, in addition to the time. Thanks.

Dave

 

[dtscho]

Thanks for adding the date to the transmissions, and fixing the talkgroup drop-down menu.

Dave

 

[lukekb]

Not a problem! Happy it got noticed! I'll have to go in and add the talkgroups you have been finding. Thanks!

- Luke

 

[KI4IHC]

This is great, I want to try to do the same kind of setup for Fairfax County - how tricky do you think it'd be to recreate with a few $30 RTL-SDR dongles instead of the HackRF?

 

[lukekb]

It wouldn't be too tough to do... Most of the trouble is getting GnuRadio setup. You would have to change my code around a bit. You would have to do some sort of mapping between the target freq and what RTLSDR to use. You do need a bit of CPU, but the Fairfax system might be quieter. Do you know if they have a SmartNet system? If it is P25, it would need a real overhaul.

 

[dw2872]

Monitor Site for DC FD, EMS & City Services

This is awesome. Great work!

 

[dw2872]

A couple unknowns that have showed up:

TG-34368 is the maintenance channel at St Elizabeth's Hospital (that's also listed in Radio Reference)
http://www.openmhz.com/scanner/tg-34368

TG-35792 is Navy Yard Anacostia, they've been sending radio techs out to do radio checks/testing all around their navy base recently, so this may be new
http://www.openmhz.com/scanner/tg-35792

TG-35920 is some kind of railroad yard operations that have only been active on the air the for the last two Tuesdays (Nov 26th and Dec 3rd) only between 8 to 9 am
http://www.openmhz.com/scanner/tg-35920

Do you know why when you click the chain link symbol on the right side of one of these unknown TG transmissions, why it goes to a page that says, "Internal Server Error"?

For the transmissions that have a known/listed TGs, it would normally take you to a page like this:
http://www.openmhz.com/call/529df5167e253ed62c001c28
but it does not do that for unknown TGs even though it looks like it should (from looking at the link address).

Also, is there any way to right mouse click on any area or link to download and save a specific transmission mp3 file, similar to the way Radiocapture.com does with the play button? Or like "Super Trunking Scanner - Santa Clara" http://scanner.rachelbythebay.com/main has when you click the gear operations button on the far right side of each transmission and it opens to a pop-up that lets you right mouse click the little circle next to the call ID number to download the MP3 file.

Thanks for the awesome online resource!

 

[lukekb]

Good catches! I will add those in, along with the talk groups Dtscho found. I must have a bug where the Call page gets messed up on Unknown calls because the lookup fails. I have the TG hardcoded in a list.

I will also add a link to the audio files for each call. You can get the file now if you goto one of the pages for a call and look at the source and look for a meta tag in the header that lists the file.

I looks like DC may have switch control channel freq or something like that. My system isn't picking up any calls. I will have to take a look and see what is up.

- Luke

 

[dw2872]

It may have to do with the Unknown calls being labeled "Uknown" (I just noticed it is missing the N after the U). Maybe there is a mismatch in that and the call page (which may be spelled correctly). Just a guess?

Thanks for the tip about the source with the file name. I didn't know they had an m4a extension. I was looking everywhere for mp3!
http://openmhz.com/media/2013/10/17/2720-1384745542.m4a

Still can't get the audio file for the Unknown TGs though, because it won't link to the page with the call yet because of the bug. Unless I misunderstood what you were saying. But that's ok for now.

Thanks for all the hard work on this!

In the next two months I want to set up something like this for the P25 Phase-1 system in Colorado Springs, CO. I know Matt, who set up the RadioCapture one in Denver on the EDACS system, but P25 will be somewhat different and for the site near me in Colo Springs since the channels span a little more than 5 MHz, so some of the comms would get left out using something with only a 5 MHz span (besides it being P25, but at least it is not Phase-2 like your local Project-25 system that a lot of the PD migrated over from the Project-16 your FD/EMS is on.

 

[lukekb]

Cool - I think I got it fixed so that Call link should work. I also added in the St. E's Maintenance. I also added a link right to the audio on the list page for downloading it. You will have to right click and 'save target'.

I went with the .m4a file type because I am trying to work towards integrating a bit with Twitter and they like that format.
Matt's system, Radio Capture, is pretty awesome. I have been emailing with him a bit. I am not sure if anyone has put together great software for decoding P25 trunking. You should check out the HackRF board, it can cover up to 20MBPs and Mike Ossman, who created lives out in CO. I am hoping they keep the P16 system going for a bit longer in DC. I guess I can always switch to covering our subway system, which is P16 too... Let me know how it goes!

 

[dw2872]

Works great. Thanks! Yeah, Matt said he would help me out when I set mine up here in Colorado Springs. I can't wait to start that project in a couple months. We need more of these online and I plan to make the Colo Springs one available too.