[ARC5] ADS-B article - ADS-B versus HF SSB ?

[Brooke Clarke]

Hi Hue:

Here's the email I sent Jo at the WSJ:
---------------------
Hi Jo:

The subject article is a little misleading.

During W.W.II the military developed IFF transponders
https://en.wikipedia.org/wiki/Identification_friend_or_foe
and later commercial aircraft enhanced that system.
https://en.wikipedia.org/wiki/Transponder_(aeronautics) <https://en.wikipedia.org/wiki/Transponder_%28aeronautics%29>
The latest wrinkle is ADS-B
https://en.wikipedia.org/wiki/Automatic_dependent_surveillance_%E2%80%93_broadcast
https://en.wikipedia.org/wiki/Automatic_dependent_surveillance_%E2%80%93_broadcast#Space-based_ADS-B
https://en.wikipedia.org/wiki/Automatic_dependent_surveillance_%E2%80%93_broadcast#US_implementation_timetable - started 
2006 in the U.S.
All of the above systems make use of 1030 and 1090 MHz UHF line of sight query and response signals.

The ADS-B system does NOT work over oceans!  Hence the loss of MH370 in March 2014 which has never been found.  This is 
still a problem.
https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_370

The Aireon space based ADS-B is a private business.  "The price point for Part 121 avionics is less than $40k and 
installation should be in the 20-25 MH range for most commercial aircraft." There's no way this will be used on general 
aviation planes and probably only on major international carriers pre COVID-19.  In today's climate and for many years 
to come I don't expect to see ADS-B tracking over oceans.
http://www.ads-b.com/space-based.htm
https://aireon.com/
https://patents.google.com/patent/US20180196140

Note MH370 could have then subscribed to Inmarsat
https://en.wikipedia.org/wiki/Inmarsat
services which would provide tracking, but choose not to in order to save money and it was not then and still is not now 
required to do so.

PS FlightRadar24
https://www.flightradar24.com/
and a number of similar web sights allow anyone to see where almost all the aircraft in the world are in real time.  
This started in 2006 (see above, the same time ADS-B started).
Note that MH17 was shot down in 2014
https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_17
and PS752 was shot down in 2020
https://en.wikipedia.org/wiki/Ukraine_International_Airlines_Flight_752
both of these probably were mistakes that could have been avoided if someone in the crew was running FlightRadar24 on 
their cell phone.

The shooting down of KAL007 was caused by a mistake by the navigator in the days prior to GPS.  This accident was THE 
key reason why Reagan put GPS in the public domain so as to avoid this type of mistake.
https://en.wikipedia.org/wiki/Korean_Air_Lines_Flight_007#Aftermath

-- 
Have Fun,

Brooke Clarke
https://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.

-------- Original Message --------
> Air-Traffic Control Is in the Midst of a Major Change

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