Originally Posted by
SCPL_1988
[shortened a bit]
FACTS
A-DSB signals for the C-130 were in this case continuous.
There is no evidence of "patchy" or "unreliable signals" involving this C-130.
Most A-DSB signals above 10,000 feet can be seen continuously across most continents.
Even at 6,000 feet, A-DSB is seen continuously over most of Australian flight routes.
If you provide such a feed, then you get to see all the hidden "blocked" information that you cannot see on flight aware public site. You get to have your own IP address that you can share with others to see all that info.
Now, I happen to be one of those "feeders" and together with other "feeders" we get
to see 'the big picture" and rarely do signals at altitude drop out unless typically
at the extreme end of the range say 200 to 300 NM at 35,000 feet depending on location, height and antenna.
150 miles at 6,000 feet is a no-brainer and odds are that at 6,000 feet ...
Yes, this accident happened "miles away" but
1090 Mhz Signals go a very long way at 6,000 feet and
odds are it could be seen as far afield as Albury, Canberra and Sydney let alone
the hundreds of private receivers who feed data into the system.
You decry others, but some of what you're saying simply is not fact.
The earth is not flat. Signals are limited by range, by the curvature of the earth, and surrounding terrain or obstacles.
At
35000' line of sight is about 200 NM, at
6000' 80 NM
Albury and Sydney are considerably further away than 80 miles.
Yes, in some conditions there is tropospheric ducting, refraction of the signal at a temperature inversion, along a ridge of high pressure, and VHF and UHF signals can go further, but you can't expect this all the time.
Thus my TV in southern UK sometimes has auto-tuned French channels in the programme guide, or experienced radio amateurs with the right kit have managed maybe
1000 km at UHF, but bear in mind these are more powerful transmitters, and much more directional aerials, multi-element Yagis, maybe sometimes stacked more than one in an array.
But even so, signal strength diminishes with range, and also more at higher frequencies, so even if someone can anecdotally tell us of an occasional 100 or 200 km for aircraft on 120 or 130 MHz, that doesn't prove the same range at 8 or 9 times the frequency.
The nearby terrain is only just below or above the aircraft. This can block line of sight or may cause multipath interference
Your extra information you claim you have doesn't include anything more about the aircraft systems, contrary to your know-all implications
Overall, the end of the ADS-B (sic, not your repeatedly mistyped version) derived trace is not conclusive about the fate of the aircraft.
It's a huge shame the tragic fate of these brave hard-working people is being trolled by parading ignorance