Aircraft is 1-2 minutes delayed

Are you having trouble getting Virtual Radar Server installed and running? If so then this is the place to ask about it.
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Hoggorm
Posts: 17
Joined: Mon Feb 03, 2014 12:15 pm

Aircraft is 1-2 minutes delayed

Post by Hoggorm » Mon Feb 03, 2014 12:20 pm

Hi,

I've just set up the Virtual Radar software on my computer.

Via Virtual Radar I now see aircrafts, however comparing the position displayed on Virtual Radar to the positions of aircrafts at Flightradar24 I see that the aircrafts that show up on my Virtual Radar is lagging 1-2 minutes behind the same aircraft on Flightradar24.

Any ideas what might cause this?

Thank you

agw
Posts: 2248
Joined: Fri Feb 17, 2012 3:20 am

Re: Aircraft is 1-2 minutes delayed

Post by agw » Tue Feb 04, 2014 12:16 am

There's no delay built into VRS. Which receiver are you using? There used to be a delay on the feed from old versions of BaseStation but I think that was five minutes.

Hoggorm
Posts: 17
Joined: Mon Feb 03, 2014 12:15 pm

Re: Aircraft is 1-2 minutes delayed

Post by Hoggorm » Tue Feb 04, 2014 10:54 am

I'm using a USB TV-dongle modified with the ADSB# software and a homemade antenna.

Today I tried to change the Timeout setting in ADSB# from 120 sec to 10 sec, and that might have helped. The delay is much less now, if any at all.

I do not know it that actually was the problem, but it seems to have helped at least.

jonfear
Posts: 365
Joined: Sat Feb 09, 2013 12:15 pm
Location: Wick St Lawrence
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Re: Aircraft is 1-2 minutes delayed

Post by jonfear » Tue Feb 04, 2014 6:04 pm

It maybe better to use the RTL1090 software published by Jetvision. Just google "RTL1090" and follow the link. The latest version is RTL1090 "SCOPE" BETA VERSION 3 (151). I have used this with no delay that you are describing. It also has a handy scope for checking against your VRS output. If ADSB# works then so should RTL1090. They use many common components.

It has many command line switches which may come in handy if you propose to share your data with others.

I do not use this anymore as I am now moving in the direction of super accurate dump1090 output from Raspberry Pi devices using the same R820T device.

Hope this helps

Jon
http://www.360radar.co.uk, the new name for MLAT Radar in the UK and Western Europe.

Former PP feeder Bm. No longer feeding. I do not have time to sort out imaginary problems with NTP
when it has been working fine for 2+ Years.

Hoggorm
Posts: 17
Joined: Mon Feb 03, 2014 12:15 pm

Re: Aircraft is 1-2 minutes delayed

Post by Hoggorm » Tue Feb 04, 2014 7:13 pm

Okey,

I'll check it out tomorrow I think.

There still are some delay to what is seen at Flightradar24. I find it strange since FR24 data has to go through FR24 servers first, while what I see on Virtual Radar Server is "live".

Maybe changing to RTL1090 might fix the problem.

agw
Posts: 2248
Joined: Fri Feb 17, 2012 3:20 am

Re: Aircraft is 1-2 minutes delayed

Post by agw » Tue Feb 04, 2014 10:20 pm

I've had a brief look at the ADSB# source and from what I can see the timeout just determines how long ADSB# will consider an ICAO to be good. If it doesn't receive a message for a given ICAO after the timeout period expires then it removes the ICAO from its list of good ICAOs, after which any further message from the ICAO will presumably have to go through its confidence checks before it considers it likely to be a valid message. I would imagine that it's not passing on those messages that aren't considered valid, but I didn't get that far into the code to know for sure.

Hoggorm
Posts: 17
Joined: Mon Feb 03, 2014 12:15 pm

Re: Aircraft is 1-2 minutes delayed

Post by Hoggorm » Wed Feb 05, 2014 4:57 pm

Early this morning I changed from ADSB# to RTL1090 as suggested by jonfear. It took some time to understand the new software, but I got it to work eventually.

For all day now, there has been no lag at all. In fact the Virtual Radar display appears to be just a little ahead of the Flightradar24 display - somthing that makes sence since the data do not pass the Flightradar24 servers.

:)

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