AirNav RadarBox
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
 


Author Topic: MODE-S  (Read 4349 times)

0 Members and 1 Guest are viewing this topic.

Jono_Kzn

  • New Member
  • *
  • Posts: 15
MODE-S
« on: June 11, 2010, 04:02:10 PM »
Hi,

Howcome I can hear an aircraft clearly but radarbox does not show the traffic?  The aircraft in question definately has mode-s only.

Does a mode-s transponder only broadcast when a radar station interrorgates it?

Thanks

Jono

DaveReid

  • Hero Member
  • *****
  • Posts: 1815
    • Heathrow last 100 ADS-B arrivals
Re: MODE-S
« Reply #1 on: June 11, 2010, 04:35:03 PM »
Does a mode-s transponder only broadcast when a radar station interrogates it?

If the aircraft has TCAS, it should send acquisition squitters once every second.  RadarBox should pick those up.
This post has been scanned for any traces of negativity, bias, sarcasm and general anti-social behaviour

Runway 31

  • Moderator
  • Hero Member
  • *****
  • Posts: 33499
Re: MODE-S
« Reply #2 on: June 11, 2010, 04:36:15 PM »
Jono, which aircraft is it?

Jono_Kzn

  • New Member
  • *
  • Posts: 15
Re: MODE-S
« Reply #3 on: June 11, 2010, 04:53:29 PM »
Its an ATR 72-212A

Runway 31

  • Moderator
  • Hero Member
  • *****
  • Posts: 33499
Re: MODE-S
« Reply #4 on: June 11, 2010, 05:04:59 PM »
What registration?

Jono_Kzn

  • New Member
  • *
  • Posts: 15
Re: MODE-S
« Reply #5 on: June 11, 2010, 05:13:01 PM »
5H-PWD

ACW367

  • Guest
Re: MODE-S
« Reply #6 on: June 11, 2010, 05:13:19 PM »
There are two forms of transponder, Mode S or Mode S ADS-B. Only the ADS-B version includes positional data as derived from onboard navigation systems. As the non-ADS-B do not transmit their coordinates, radarbox cannot plot them on a map. Most aircraft below jet airliner size have not yet been fitted with ADS-B transponders

ACW367

  • Guest
Re: MODE-S
« Reply #7 on: June 11, 2010, 05:18:58 PM »
Radarbox receives encoded radio messages rather than radar images. Only if that broadcast radio message contains a position report can it be plotted on radarboxes virtual map

Runway 31

  • Moderator
  • Hero Member
  • *****
  • Posts: 33499
Re: MODE-S
« Reply #8 on: June 11, 2010, 05:20:05 PM »
Jono could you forward the hex code please.

Jono_Kzn

  • New Member
  • *
  • Posts: 15
Re: MODE-S
« Reply #9 on: June 11, 2010, 05:26:25 PM »
I sent it via PM

Jono_Kzn

  • New Member
  • *
  • Posts: 15
Re: MODE-S
« Reply #10 on: June 11, 2010, 05:26:49 PM »
Yes I understand that but the aircraft in question has mode-s which doesnt display all the time.  I pick it up when it is close but it dissapears off the screen however i can hear the ATC traffic clearly....

Just wondered howcome i can hear the atc clearly but the radarbox does not show its recieving the mode-s traffic??

DaveG

  • Hero Member
  • *****
  • Posts: 543
Re: MODE-S
« Reply #11 on: June 11, 2010, 05:31:04 PM »
Yes I understand that but the aircraft in question has mode-s which doesnt display all the time.  I pick it up when it is close but it dissapears off the screen however i can hear the ATC traffic clearly....

Just wondered howcome i can hear the atc clearly but the radarbox does not show its recieving the mode-s traffic??

Simple answer to this could be your RB aerial has a blind spot at where the aircraft is either on distance, direction or alt
Cornwall, UK

Jono_Kzn

  • New Member
  • *
  • Posts: 15
Re: MODE-S
« Reply #12 on: June 11, 2010, 06:00:00 PM »
I have a DPD antenna is there any specific tips for placement?  I have it about 16 feet in the air.  However there are quite a few trees around me...

ACW367

  • Guest
Re: MODE-S
« Reply #13 on: June 11, 2010, 06:33:38 PM »
Jono

Mode S radio signals are line of sight so high ground trees block the transmissions if the aircraft goes behind them.

PS I have sent you a PM on a different topic.