Will it work high?
Will it work high?
I am looking to track a weather balloon that will be flying at about 80,000 - 100,000 feet. Would it be able to be tracked with one of these phones?
We never used that way but I think it'll work if there's cell signal up there. But I really doubt the signal can reach that high. Here is a report that might help a bit: http://www.datasync.com/~rsf1/cell-air.htm it doesn't look like working.
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well.
the in-theory of that is, when you're up there, you're usually on a plane, and a cell can interfere with the plane's instruments, so thats a no -no.
at that altitude... yeah, you're probably not going to be able to reach a cell tower anyway.
Explaination on that, is the cell towers broadcasts are mostly linear. meaning they go out in cone shapes from the panels. Most of the time, they stay within a mile or two of the ground.
planes and other air craft are usually low enough to be able to aquire the signal. i've done it at 10,000 feet on a lear.
but the altitude you want, there is little chance of a signal.
the in-theory of that is, when you're up there, you're usually on a plane, and a cell can interfere with the plane's instruments, so thats a no -no.
at that altitude... yeah, you're probably not going to be able to reach a cell tower anyway.
Explaination on that, is the cell towers broadcasts are mostly linear. meaning they go out in cone shapes from the panels. Most of the time, they stay within a mile or two of the ground.
planes and other air craft are usually low enough to be able to aquire the signal. i've done it at 10,000 feet on a lear.
but the altitude you want, there is little chance of a signal.
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fyi. use of a cell phone on a plane, any plane, including a private plane or hot air balloon is still illegal in the states. the only reason i got away with it, it was a nextel, and a goverment owned nextel.
nextel is still technically a smr radio, not a cell phone.
which explains why the hot air baloon chase teams i've worked with use nextels rather then cells on the aircraft.
nextel is still technically a smr radio, not a cell phone.
which explains why the hot air baloon chase teams i've worked with use nextels rather then cells on the aircraft.
another question
Also, if it dosent work WHILE flying, would it send location when it goes down?
Re: another question
Certainly it'll work when it goes down to some point low enough but I don't know the limit. Might be a few thousands feet high I guess.Jackichino wrote:Also, if it dosent work WHILE flying, would it send location when it goes down?
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re-read my second post.Jackichino wrote:It's an unmanned balloon, so I think it is legal to use.
nextel is a SMR radio, not a cell phone. In theory, its legal.
Then read my first post. It most likely wont work anywhere above 10-15.
It will work at any point that the balloon is low enough though.
So for a recovery purpose, it should be good for you.
re: legality. There are some relevant links collected at http://en.wikipedia.org/wiki/Mobile_phones_on_aircraft (see "Relevant Laws"). However, if you follow the link to reference 7 (http://www.house.gov/transportation/avi ... 5memo.html) you will see that Nextel is listed in the 800MHz spectrum, and therefore prohibited. If someone can show that the iDEN phones use 1.9GHz, that would reverse this tentative conclusion (but the Moto technical overview of iDEN I have, dated, Aug 2000, suggests that it use 800MHz). The relevant FCC ruling, 47 CFR 22.925 can be found at http://edocket.access.gpo.gov/cfr_2004/ ... 22.917.pdf.
re: feasibility. I have had an i415 connect to a cell tower 50 miles distant, which is over 250,000 feet. (See the map on http://www.ylem.org/Hitchhikers/HandP.html. If you zoom out a step, you'll see a cell tower located in San Francisco. The phone connected to this while on Mt Hamilton to the east of San Jose, 50 miles distant.) Of course, this may have been a fluke.
re: feasibility. I have had an i415 connect to a cell tower 50 miles distant, which is over 250,000 feet. (See the map on http://www.ylem.org/Hitchhikers/HandP.html. If you zoom out a step, you'll see a cell tower located in San Francisco. The phone connected to this while on Mt Hamilton to the east of San Jose, 50 miles distant.) Of course, this may have been a fluke.
dammit. i closed the window as i was typing a reply.
first off, look at this picture (from the report linked in this thread)
understand why your mountain example worked, but a aircraft at altitude would not work?
also, nextel, which does use 800 AND 900 spectrum, uses SMR spectrum, not cellular. Its a SMR radio, which has specific rules other then cell phone specific rules.
Yes, it would be prohibited to use a nextel on a manned aircraft, especially commercial.
Yes, you could use an SMR radio onboard an aircraft with pilot permission.
Neither of these really apply to the situation though.
An unmanned balloon doesnt operate under IFR, nor VFR.
It would be legal for the phone to be onboard the balloon, it just wouldnt work at those altitudes.
first off, look at this picture (from the report linked in this thread)
understand why your mountain example worked, but a aircraft at altitude would not work?
also, nextel, which does use 800 AND 900 spectrum, uses SMR spectrum, not cellular. Its a SMR radio, which has specific rules other then cell phone specific rules.
Yes, it would be prohibited to use a nextel on a manned aircraft, especially commercial.
Yes, you could use an SMR radio onboard an aircraft with pilot permission.
Neither of these really apply to the situation though.
An unmanned balloon doesnt operate under IFR, nor VFR.
It would be legal for the phone to be onboard the balloon, it just wouldnt work at those altitudes.
Plausible, but not definitive. The figure is captioned as qualitative, not quantitative. Also, the simple experiments described used voice comms; it may be that repeated attempts at sending a short data packet stand a much better chance of successful transmission. (Aside from that, perhaps it's worth mentioning that the cited page is part of a 9/11 conspiracy web site, making a lot of wild claims.)madrabbitt(NSI) wrote: understand why your mountain example worked, but a aircraft at altitude would not work?