Flight Information Display (FID)
Goodwood aerodrome is equipped with a multi-protocol, CAA approved, Flight Information Display. It is currently operational and being used to verify position reports and sometimes to advise of potential traffic. The FID relies on a robust network of ground receivers, which allows it to display a lot more traffic to the FISO than most portable or even permanent avionics equipment.
When viewing the below video you will see that out of 21 conspicuous aircraft – 12 disappear if we disable Mode S display. That means that more than half of the airborne electronically conspicuous aircraft are likely not to be visible through your portable EC or even on a permanent ADS-B ‘IN’ receiver.
See below sections for further information to understand key differences between various EC solutions. Alternatively you may view a briefing slide pack available as downloadable PDF.
Various types of EC
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Emit signal only when interrogated by ground radar or airborne TCAS
Do not contain GPS location in the message and are therefore NOT visible to most portable EC technologies
Mode S is visible to the Goodwood FISO on their FID thanks to a very wide spread network of receivers that have been deployed. When a Mode S signal received by at least 4 receivers – the aircraft position can be identified
Operate on 1030 MHz for interrogations and 1090 MHz for transmissions
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Emit signal actively and regularly
Could be in a form of full-power permanently installed transponder, but technically it is done by "upgrading" already installed Mode S (also known as Mode S Extended Squitter).
Contains GPS location information and is visible by most portable EC devices with ‘IN’ capability
Likely to require additional software/hardware for ‘IN’ capability to see other traffic
Operate on 1030 MHz for interrogations of Mode S and 1090 MHz for transmissions of Mode.S and ADS-B
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Emit signal actively and regularly like a permanent unit, but at reduced power; contains GPS location.
As a standalone unit it is not visible to most ANSPs in the UK and does not meet the requirements for airspace that require a Mode S transponder
If you already have Mode S Extended Squitter (full power ADS-B transponder), then only ‘IN’ mode can be enabled
Operate on 1090 MHz for transmissions of ADS-B
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Technology that could utilise the existing network of ground receivers to identify most conspicuous aircraft and re-transmit their positions to compatible airborne receivers on 978 MHz
That means that when in reception of TIS-B, you will be able to see the positions of the Mode S only aircraft or aircraft that are further away, but within reach of the network
TIS-B traffic could be received by correctly configured permanently installed avionics equipment or by portable units (such as SkyEcho2) if secondary 978 MHz receiver functionality is available
TIS-B can transmit Mode S aircraft as well as ADS-B (for increasing visibility range), but our trial transmits Mode S only
Being able to distinguish TIS-B traffic is important as the position of Mode S targets is likely to be a few seconds delayed due to required processing