AirNav Systems Forum

AirNav Radar => AirNav Radar Discussion => Topic started by: lovemuscle on July 14, 2009, 09:02:21 AM

Title: whats the best refresh rate to use?
Post by: lovemuscle on July 14, 2009, 09:02:21 AM
Just wondered what the best refresh rate is to use,i wonder what all you experienced member are using?

Is there any disadvantage to using the fastest refresh rate ie 100ms.

thanks in advance Gary
Title: Re: whats the best refresh rate to use?
Post by: AirNav Support on July 14, 2009, 09:06:54 AM
Thats probally "overkill". ADS-B messages are sent twice every second.

So 500ms would be fine, though it also depends whether your computer can handle the load.
Title: Re: whats the best refresh rate to use?
Post by: tarbat on July 14, 2009, 09:58:53 AM
ATC radar screens typicaly update every 4 seconds I think.  So I use 4000ms for a more realistic simulation of real ATC radar.
Title: Re: whats the best refresh rate to use?
Post by: lovemuscle on July 14, 2009, 10:18:15 AM
ummm interesting,i would of thought they would update faster than that,might give it a go,cost nothing.:)
Title: Re: whats the best refresh rate to use?
Post by: Spaice on July 14, 2009, 10:51:40 AM
I have set my RB to 1000ms for refresh, you are right that it cost nothing, but it might have an impact on the resources of your computer.  I,m sure that if ATC could have a refresh rate higher than 4 seconds they would.
Title: Re: whats the best refresh rate to use?
Post by: DaveReid on July 14, 2009, 11:12:11 AM
Quote from: Spaice on July 14, 2009, 10:51:40 AM
I'm sure that if ATC could have a refresh rate higher than 4 seconds they would.

You try spinning a massive PSR head at more than 15 rpm  :-)
Title: Re: whats the best refresh rate to use?
Post by: Deadcalm on July 14, 2009, 11:32:23 AM
23cm radar - 6 sec update, 10cm radar 4 secs.

DC
Title: Re: whats the best refresh rate to use?
Post by: Spaice on July 14, 2009, 12:15:59 PM
That was my point really, they are limited to 4 sec refresh because of technical limitation, however if they could spin the PSR head at a faster rate ATC would be very happy :)
Title: Re: whats the best refresh rate to use?
Post by: malc41 on July 14, 2009, 12:19:59 PM
and would probably shake the tower/building to bits !
Title: Re: whats the best refresh rate to use?
Post by: atcukmatty on July 14, 2009, 02:40:03 PM
i study avionics at uni, i learnt all this this last year. If you have a high scanning speed and the pulse repetition frequency is low some targets may be missed becuase of the time interval between pulses. So if you want a high scanning speed it requires high PRF, and the more pulses transmitted per second means the display will be clearer and brighter (talking about PSR).
I went to air traffic control for my work experience a couple of years ago and im pretty sure it updated faster than 4 seconds.
Title: Re: whats the best refresh rate to use?
Post by: malc41 on July 14, 2009, 02:45:29 PM
Terminal Airport Surveillance radar updates at 4.8 seconds (12.5 rpm antenna
rotation)

Airport surveillance and SSR usually at 4 seconds (15 rpm)

PAR < 1 sec

Title: Re: whats the best refresh rate to use?
Post by: FlyOverMe on July 15, 2009, 01:26:33 AM
Do the  ADS-B transponders on Aircraft respond to a ground based interrogation from radar? Or do they transmit independently at a regular interval?
Title: Re: whats the best refresh rate to use?
Post by: FlyOverMe on July 15, 2009, 01:30:15 AM
I leave my RadarBox set at 4000ms
Title: Re: whats the best refresh rate to use?
Post by: DaveReid on July 15, 2009, 06:22:47 AM
Quote from: FlyOverMe on July 15, 2009, 01:26:33 AMDo the  ADS-B transponders on Aircraft respond to a ground based interrogation from radar? Or do they transmit independently at a regular interval?

Both.