US warns of 5G Flight Diversions
12-12-2021, 09:48 AM
#31
Gets Weekends Off
Joined APC: Mar 2017
Posts: 3,663
Originally Posted by sailingfun
In January 2017, newly inaugurated president Donald Trump designated Pai as FCC chairman.[6][7] He is the first Indian American to hold the office. In March 2017, Trump announced that he would renominate Pai to serve another five-year term (remaining Chairman of the FCC).[8] Pai was confirmed by the U.S. Senate for an additional five-year term on October 2, 2017.[9] Pai is a proponent of repealing net neutrality in the United States and, on December 14, 2017, voted with the majority of the FCC to reverse the decision to regulate the internet under Title II of the Communications Act of 1934. Pai resigned on January 20, 2021, the day of Joe Biden's inauguration as President of the United States.[10]
12-12-2021, 05:16 PM
#32
Prime Minister/Moderator
Joined APC: Jan 2006
Position: Engines Turn Or People Swim
Posts: 39,293
Originally Posted by SonicFlyer
hmmm... wouldn't it be a simple matter of just time differential using a FFT? It knows when it transmitted, and then it knows how long it took to receive the same signal back, thus can calculate distance based on those two figures? Same as police radar works?
In the case of RADALT, I'm guessing the distance is probably just too small to reliably and precisely measure with time differential. The required precision is very, very high (probably 1-2 feet I'd guess) and at close range that would require some VERY, VERY precise timing... at the speed of light. Normal radar measures distance in miles with precision in thousands or maybe hundreds of feet. Could it be done? Maybe. It might even be easy with the latest technology but RADALTS have been around for a while, and nobody wants to retrofit the whole fleet.
12-12-2021, 05:44 PM
#33
Gets Weekends Off
Joined APC: Apr 2017
Posts: 3,596
Originally Posted by rickair7777
Police radar actually uses dopler shift of the emitted freq, since it's looking for relative velocity, not distance. Not the same as time differential, which is what longer-range radars use.
In the case of RADALT, I'm guessing the distance is probably just too small to reliably and precisely measure with time differential. The required precision is very, very high (probably 1-2 feet I'd guess) and at close range that would require some VERY, VERY precise timing... at the speed of light. Normal radar measures distance in miles with precision in thousands or maybe hundreds of feet. Could it be done? Maybe. It might even be easy with the latest technology but RADALTS have been around for a while, and nobody wants to retrofit the whole fleet.
In the case of RADALT, I'm guessing the distance is probably just too small to reliably and precisely measure with time differential. The required precision is very, very high (probably 1-2 feet I'd guess) and at close range that would require some VERY, VERY precise timing... at the speed of light. Normal radar measures distance in miles with precision in thousands or maybe hundreds of feet. Could it be done? Maybe. It might even be easy with the latest technology but RADALTS have been around for a while, and nobody wants to retrofit the whole fleet.
12-12-2021, 06:41 PM
#34
Gets Weekends Off
Joined APC: May 2010
Position: Baja Vermont
Posts: 5,177
Originally Posted by rickair7777
I'm pretty sure they do not, their actual functionality depends on waveform and frequency shifting so it would be hard to overlay encoding on top of that.
RADALTS on the same airframe use a frequency offset. De-confliction between aircraft is apparently just based on distance, ie two planes will not be over the MM at the same time, and unrestricted parallel approaches require at least several thousand feet of offset.
Lot's of technical reading here...
https://www.google.com/url?sa=t&rct=...npGZmHndfU2fdZ
This Honeywell guy's analysis seems to indicate that an individual cell phone in the wrong place at the wrong time might have the power to interfere... he says 10mW, and the phones themselves can put out more than that.
RADALTS on the same airframe use a frequency offset. De-confliction between aircraft is apparently just based on distance, ie two planes will not be over the MM at the same time, and unrestricted parallel approaches require at least several thousand feet of offset.
Lot's of technical reading here...
https://www.google.com/url?sa=t&rct=...npGZmHndfU2fdZ
This Honeywell guy's analysis seems to indicate that an individual cell phone in the wrong place at the wrong time might have the power to interfere... he says 10mW, and the phones themselves can put out more than that.
[QUOTEIn the most recent crash scenario one of two altimeters carried by the 737 incorrectly measured the altitude as being well below 100ft when in fact the aircraft was still near 3000ft. But this data caused the Autopilot to retard the engines to idle, deploy wing flaps for landing and lower the landing gear. With the aircraft at 3000ft and a sudden reduction in thrust and a dramatic increase in drag due to the lower landing gear, the aircraft stalls in flight and must be recovered by quick action of the pilots. ][/QUOTE]
I’m pretty sure the B737 doesn’t have auto configuration. If he designs Honeywell avionics, that might explain my hatred for them,
12-13-2021, 07:12 AM
#35
Prime Minister/Moderator
Joined APC: Jan 2006
Position: Engines Turn Or People Swim
Posts: 39,293
Originally Posted by galaxy flyer
Interesting, but the author is innocent of how planes are flown,
I’m pretty sure the B737 doesn’t have auto configuration. If he designs Honeywell avionics, that might explain my hatred for them,
I’m pretty sure the B737 doesn’t have auto configuration. If he designs Honeywell avionics, that might explain my hatred for them,
12-13-2021, 11:30 AM
#36
Gets Weekends Off
Joined APC: Nov 2017
Posts: 2,099
Originally Posted by LumberJack
It was Ajit Pai who fast tracked the sale of spectrum that is causing this. He knew about it ahead of time but didn't address the issue. He's the same one who eliminated net neutrality. Take a wild guess who appointed him in January 2017.
The current FCC board (including the new chairman) have been repeatedly asked to reconsider this decision and nothing. The wireless lobby pays all sides.
12-14-2021, 04:30 PM
#38
Gets Weekends Off
Joined APC: Nov 2017
Posts: 2,099
US warns of 5G Flight Diversions
Originally Posted by rickair7777
Somebody must be getting paid to ignore fundamental electro-physics principles such as frequency bleed.
The incentives are all on the side of the the wireless carriers. I’ve read other boards where people try to explain this but the phone slaves go insane when it means their high speed internet will be delayed a month, let alone more.
12-16-2021, 09:37 AM
#39
Prime Minister/Moderator
Joined APC: Jan 2006
Position: Engines Turn Or People Swim
Posts: 39,293
Good article, points out that harmful interference has not yet been demonstrated...
https://www.wusa9.com/article/news/v...1-e0c7bdb53528
IMO, the FAA is correct to be cautious until they have a more definitive answer (as opposed to "the Europeans are doing it").
https://www.wusa9.com/article/news/v...1-e0c7bdb53528
IMO, the FAA is correct to be cautious until they have a more definitive answer (as opposed to "the Europeans are doing it").
12-16-2021, 10:19 AM
#40
Gets Weekends Off
Joined APC: May 2016
Posts: 324
Originally Posted by rickair7777
Good article, points out that harmful interference has not yet been demonstrated...
https://www.wusa9.com/article/news/v...1-e0c7bdb53528
IMO, the FAA is correct to be cautious until they have a more definitive answer (as opposed to "the Europeans are doing it").
https://www.wusa9.com/article/news/v...1-e0c7bdb53528
IMO, the FAA is correct to be cautious until they have a more definitive answer (as opposed to "the Europeans are doing it").
Thread
Thread Starter
Forum
Replies
Last Post
