transponder basics l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Transponder Basics PowerPoint Presentation
Download Presentation
Transponder Basics

Loading in 2 Seconds...

play fullscreen
1 / 13

Transponder Basics - PowerPoint PPT Presentation


  • 632 Views
  • Uploaded on

Transponder Basics. Phil King, Herefordshire Gliding Club. Overview. Secondary Surveillance Radar Mode A Mode A/C Mode S (selective) Mode S/ES (extended squitter) ADS-B (Automatic Dependent Surveillance Broadcast) STCA (Short Term Conflict Alert)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Transponder Basics' - paul2


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
transponder basics

Transponder Basics

Phil King,

Herefordshire Gliding Club

overview
Overview
  • Secondary Surveillance Radar
  • Mode A
  • Mode A/C
  • Mode S (selective)
  • Mode S/ES (extended squitter)
  • ADS-B (Automatic Dependent Surveillance Broadcast)
  • STCA (Short Term Conflict Alert)
  • TCAS (Traffic alert Collision Avoidance System)
  • Flarm
acronyms
Acronyms
  • ACAS – Airborne Collision Avoidance System
  • ADS-B – Automatic Dependent Surveillance Broadcast
  • CAT – Commercial Air Traffic
  • EHS – (Mode S) Enhanced Surveillance
  • ELS – (Mode S) Elementary Surveillance
  • ES – Extended Squitter
  • GA – General Aviation
  • LAST – Light Aviation SSR Transponder
  • LPST – Low Power SSR Mode-S Transponder
  • SSR – Secondary Surveillance Radar
  • STCA – Short Term Conflict Alert
  • TCAS – Traffic alert Collision Avoidance System
  • TMZ – Transponder Mandatory Zone
  • TRA(G) – Temporary Reserved Areas (Gliders)
  • UAV – Unmanned Aerial Vehicle
secondary surveillance radar
Secondary Surveillance Radar
  • Primary radar relies on passive reflection
  • Secondary radar co-located with primary
  • SSR beam interrogates transponders
  • Transponder reply depends on its mode
  • ATC computers use SSR to tag primary echoes with identifier and height
mode a
Mode A
  • Developed from 2nd World War IFF (Identification Friend or Foe)
  • Limited number of squawk codes (4096)
  • Non-selective – all transponders respond to every interrogation broadcast
  • Typically high power requirements:
    • Frequent transmissions
    • Power hungry transmitter
mode a c
Mode A/C
  • Incorporates mode A … plus …
  • Altitude (i.e. Flight Level) as well as identifier
  • Extra power required to heat the altimeter to a constant temperature
mode s selective
Mode S (selective)
  • Incorporates mode A/C ability … plus …
  • Less power required because:
    • Transmitter is typically more efficient
    • Altimeter does not need a heater
  • Can respond selectively:
    • If the SSR interrogates selectively
    • Can reduce power even more
  • Two levels of function (and price!):
    • ELS: Elementary Surveillance (gliders & light aircraft)
    • EHS: Enhanced Surveillance (for CAT)
mode s es extended squitter
Mode S/ES (extended squitter)
  • As for mode S plus …
  • Periodically broadcasts GPS position & velocity
  • Potentially provides one half of an airborne collision avoidance system
  • Provides some interoperability with ADS-B
ads b
ADS-B
  • Broadly equivalent to Mode S/ES
  • 150 mile range
  • Does not need a ground-based radar system
  • Already in use in Alaska & Australia
  • Arguably the system of the future
stca short term conflict alert
STCA (Short Term Conflict Alert)
  • Automated system which alerts ATC
  • Requires transponders on both aircraft
  • Requires at least one aircraft to be in contact with ATC
tcas traffic alert collision avoidance system
TCAS (Traffic alert Collision Avoidance System)
  • Is an Airborne Collision Avoidance System
  • Receives transponder signals
  • Works with mode A/C, S, or S/ES
  • Mandatory for CAT
  • Useless at detecting non-transponder aircraft
flarm
Flarm
  • Good value collision avoidance
  • 11,000 in use
  • High take up in the Alps and Germany
  • Growing take up in UK
  • Short range (a few kilometres)
  • Ideal for gliders and slow speed aircraft
  • May be unsuitable for ATC or CAT
  • Unacceptable as an alternative to mode S