Slashdot Mirror
Space On a Shoestring
An anonymous reader writes, "Three engineering students from Cambridge University plan to send an unmanned craft into space for £1,000 ($1,880) and have just sent a test mission up 32 km for a lot less. Their snaps from the upper atmosphere are impressive, and were taken by a balloon equipped with off-the-shelf technology including GSM text messaging, radio communications, and an ordinary 5-megapixel camera. They now plan to use a similar craft as a launching stage to get a cheap rocket into space." There's also a video of the balloon launch.
Picture this, soon their balooning costs will skyrocket to reach even greater heights.
Have you read my journal today?
http://www.grc.nasa.gov/WWW/K-12/Numbers/Math/Math ematical_Thinking/designing_a_high_altitude.htm
http://www.amsat.org/amsat/balloons/balloon.htm
I'm not fat, just big boned...
So GSM phones do work at that height?
Why do we need inflight GSM mini stations then?
-- ubersonic Kfz Versicherung
How much does it cost to put a rocket into space? Three engineering students at Cambridge University in the UK reckon they'll be able to do it for just £1000 ($1879). And they've just sent a lunchbox-sized aircraft, called Nova 1, into the stratosphere where it captured some very nice pictures of the Earth and the upper atmosphere.
Nova 1 was carried to an altitude of 32 km beneath a high-altitude helium balloon and snapped more than 800 images, many like the one above.
The students involved, Carl Morland, Henry Hallam and Robert Fryers, have also released a short video showing the launch in Cambridge. When the balloon carrying the Nova 1 finally burst due to expansion, a parachute deployed to carry it safely back to Earth.
Nova 1 featured some simple, off-the-shelf technology. This included GSM text messaging as well as radio for communications and an ordinary 5 megapixel camera. The students tracked their payload's descent using telemetry and by simply following it in a car.
Eventually they hope to fit a rocket beneath a balloon and use this to carry their craft to 100 km - the edge of space - all for just £1000. It would be no mean feat. Especially when you consider £1000 is about price of one door handle on the space shuttle. And that Anousheh Ansari just paid 13,245 times that for a tourist trip to the International Space Station. Good luck guys.
n/t
you had me at #!
I was in the same program last year at a different university (LSU). The stuff is somewhat exciting, but I don't really think it's newsworthy. I feel like it only made the news because it of the famous university name tacked on...
Regardless, what they've done is an outstanding achievement. The year before mine our school tried to take a picture up there (~100,000 feet) but it didn't work because the cold temperature changed the timing of some electronics, causing them to malfunction =/
I was in charge of the thermal stuff, and let me tell you, it's pretty hard to keep it warm but not so warm that the sun toasts it. And keep in mind the payload, as they call it, could only be 500 grams!
Seems to me, if they can start launching satellites for tens of thousands of dollars, they'll have no end of business coming their way. Despite surprised optimism, sending a camera to high altitudes is no major feat. The US gov. has been sending small payloads up in balloons since WWII.
In other news, Steve Balmer was today announced as the MS space program's launch mechanism of choice.
Support NYCountryLawyer RIAA vs People
This (working to launching rockets from baloons) has been done in the US for quite some time. There are plenty of student baloon payload systems and in fact this week there is a confrence going this week on adressing just this topic. As far as using baloons as a launch platform, there is group from Huntsville AL http://chapters.nss.org/al/HAL5/HALO/that has been launching for quite some time. Good luck to the team from the UK but if any one realy interested in getting things done, perhaps all these individual groups should join forces. Just My 2 Cents
Faith_Healer -- The antethsis to almost everything, and the worlds worst speller.
Three engineering students from Cambridge University plan to send an unmanned craft into space for £1,000 ($1,880) They should hook up with that teenager who was building a nuclear reactor in his backyard.
Push Button, Receive Bacon
Not to demean their accomplishments ( I used to fly amateur - and model - rockets too, and greatly anjoyed it ) but let me know when they get into orbit. That is when really useful things can be done.
I'd contribute to a prize for that.
I go to the University of Kansas, we've been doing balloon flights for some time now, were currently attaching a rocket to a balloon, were even calling it a Rockoon. Get it? Rocket Balloon,
What's the fun of a high altitude balloon if you can't jump from the balloon?
"During his descent, he reached speeds up to 614 miles per hour"
"Can of worms? The can is open... the worms are everywhere."
How much did the test mission cost? (Just because it didn't get into space doesn't mean we can't learn from it)
I make websites and stuff. Buy one.
...that this isn't the mystery object NASA spotted today?
Sending rockets out into space is pretty easy, but the real trick is orbit. Cheap shots to the upper atmosphere don't do a lot of good in terms of launching satellites and other objects into orbit, although I'm sure they can provide experience with the technology. Achieving orbit requires a lot more energy. There's a reason missiles and rockets are the size they are.
A group at the NOAA Climate labs in Boulder did something similar recently. Duct taped a digital camera set to take pictures every 25 seconds to an atmospheric sounding balloon. Nice pictures of the Colorado front range from up to 90,000 feet.
http://www.cmdl.noaa.gov/gallery/balloon_flight
What self respecting nerd posts a 20 second 240 x 320 video using Raw RGB that weighs in at 69MB??!!
The source I found says space shuttle orbit at about 300 km --- the baloon only made it 32 km. From what I read about the mystery object, it was pretty close to the shuttle and most likely from the cargo bay.
Some context, to help understand this: Earth's Atmosphere, as per WikiPedia.
You can see that weather balloons are in the 18-50 km range, which is what we expect, because that's what they're using, and they got to 32 km.
It's 27574.2 kbps for goodness sake!!
I wonder what their take on the earth's curvature in those pics would be
Three engineering students from Cambridge University plan to send an unmanned craft into space for £1,000 ($1,880)...
So they're sending a high-end Dell laptop into space? It's been awhile since something blew up on the way into space.
Having made several flights lately in light aircraft I've been rather bored and have happily sat watching the bars on my mobile phone...Now I didn't realise there was a full on tin foil hat issue here though my results are as follows:
:)
Outbound from where I live on a Nokia 6230 I had signal for a decent phone call up to ~5,000 feet and could send SMS to around ~6,000 feet, soon after this I lost signal. Leaving on the way back to here I had phone signal for a call up to ~7,000 feet and lost phone and SMS at about the same time.
The Blackberry 7230 I had with me made it another 500-1000 feet over my Nokia in regards to signal though GPRS didn't fare so well. Luckily Brick doesn't require phone signal.
We tended to fly at around 12,000 feet most times and those observations from one trip seem about right for the rest plus I can confirm from having to drive several of the distances that there is full phone coverage a long the routes.
I ate your fish.
There are houses and buildings all over the region where this was launched. It could have killed someone or at the very least caused property damage. Nobody would insure these guys. They're freaking dangerous.
you had me at #!
There's a bit more information in the Register article.
Good work lads.
Firstly congratulations.
Secondly, lets not get carried away (pun intended). This is a helium balloon carrying a box with gadgets, simple and cheap yes, but heck! thats what weather balloons do.
I think it is over glorifying a simple task. What would be amazing is if they made a craft that was capable of transporting payloads or something that could be controlled (path/stability etc). Otherwise this is just a big ball of gas
Space on a shoestring could be fun [...] How about [...] a free trip to Israel.
Wait, are Israelis allowed to spam? Spam's a pork product, you know. This can't be kosher.
When I tried it from a motor glider in a fairly remote area (few cells, large areas) I got a snotty letter from Orange saying that roaming at 50kts between very non-adjacent cells made their network shit itself. I wish I'd kept the letter...
launching a giant multi-million dollar rocket filled with liquid oxygen with 2/3 of that fuel carrying just the weight of the fuel is so terribly efficient
because launching the rocket is EFFECTIVE, compared to a balloon that will only reach about midway/three-fourths of the way in the atmosphere, only to fall back to the earth. the rocket has enough to push at a force that will allow it to get into orbit. not efficient, but it's the only way we get the job done.
. o O ( TwO hEaDs ArE mOrE tHaN oNe... )
It speaks poorly of what our society has become today when their little science project - which will be found, presumably, with the busted balloon still attached to the makeshift electronics module - needs to be labelled prominently as "HARMLESS SCIENTIFIC EXPERIMENT"...
Maybe we need to start putting warnings on every weather balloon instrumentation package: "NO, NOT EVERY ELECTRONIC DEVICE YOU AREN'T FAMILIAR WITH IS A BLOODY BOMB"
That's a sounding rocket. In terms of performance, it seems comparable to the WAC Corporal of 1944, or maybe the Aerobee of 1947.
Nothing wrong with building one cheaply, but it's not a step forward.
Remember that guy with the meteorological balloon and the lawn chair who floating into the airspace of LAX?
h tml
http://www.darwinawards.com/stupid/stupid1998-11.
He should get himself a really warm coat and an aqualung, and go a bit higher!
I had signal for a decent phone call up to ~5,000 feet and could send SMS to around ~6,000 feet, soon after this I lost signal.
More likely you had too much signal. From altitude you tie up one RF channel on several dozen towers in range instead of running at reduced power on the closest tower. This blanket coverage of dozens of towers tying up a channel without the ability to hand your signal to a single tower and free up the frequency on other towers for use by others is why they don't permit phone use on aircraft. If the system is smart, it may have shut down your phone to clear the frequency as the towers noticed an even signal strength from one phone over dozens of towers. You simply did not get a tower assignment at altitude.
The truth shall set you free!
Really, if anything, the story is that someone is actually employing a good idea. That's where humans tend to fall down a bit. We've got all kinds of good ideas, but no one ever uses them. Like, this dude once had this idea about people being nice to each other, and yet only a handful of people have ever tried it. Another guy had this idea that it might be helpful to think sometimes. How many people do it? And a man once suggested that maybe, just maybe, we should let honest, intelligent people be our leaders rather than evil deceitful morons. No one has ever actually done so in all of recorded history. The youngest of those three ideas is already over 2000 years old.
I'm a little off-topic I think... Maybe I shouldn't read the CBC after 10pm. It just angries up the blood.
Who wants to phone the mobile number printed on the side and tell them the sky is raining alien satellite fire.
...just go up and keep going
It can't. It falls straight back down again. There's a small matter of mach 25 horizontal speed to achieve before it's an orbit.
For every expert, there is an equal and opposite expert. - Arthur C. Clarke
For this balloon thing though, could put the GSM unit into a downward facing pringles tube, increasing the signal strength, narrowing the transmitted area, and sticking to their "cheap, very very cheap" idea :-)
The revolution will not be televised... but it will have a page on Wikipedia
Sending up balloons is a lot of fun.
I've come from New Zealand, now living in the UK and in the process of doing this.
The only problem in the UK are the stupid OFCOM laws that prohibit the use of amateur radio frequencies in airborne stations. AFAIK you need the intermediate license to set up an unmanned station, but to be able to transmit from an airborne station you need to have the top amateur license, pay lots of £££ and apply for a Notice of variation (NOV) which is pretty unlikely.
The most impressive part of the whole project is not the fact they sent up a balloon (lots of people have done this, TJ Bordelons freespace website shows him doing in years ago), but the fact that they did it within the limitations set my OFCOM in the UK. In the case of this particular balloon, they managed to send 1200 baud telemtry from the balloon using only 10mW erp of power in the 434Mhz band. And thats erp, so you aren't even allowed to use a 10mW transmitter with a high gain transmitting antenna. You HAVE to use 10mW with a low gain antenna (technically speaking 0dB of gain) and then direct a high gain antenna from the ground and do one heck of a lot of DSP on the signal to get that 1200baud back out the other end.
In the US, people simply throw a 5 Watt radio hooked up to an APRS encoder and a GPS in a box with their pakage - they can pretty much use basic antennas at both ends with no problems. It helps also in the us they can use 14MHz from the air which has slightly better range for given Freq than compared to 434Mhz
Great idea! If only more people got involved in experimenting with aerospace. We might actualy get the flying cars we've been dreaming of sense the 20th century
Radio waves are dragged back down to earth by gravity. The only reason a GSM phone wouldn't work is range to the towers, and it's only 20 miles.
Deleted
Ballons probably don't need the same sort of clearance. Many weather ballons are launched from weather stations which are often located at airports. I used to work for a company building weather ballon tracking equipment and we'd go test our prototype kit at the baloon launch site which was right next to the end of an international airport runway (right in the high security area next to where you see the planes land with puffs of smoke coming off their tyres). At least twice I can recall flying along at altitude in a commercial airliner and hearing the pilot say: "folks if you look out of the left window you can see a weather ballon". These things carry radar reflectors etc and pose very little danger to aviation.
Engineering is the art of compromise.
Maybe that's a turban legend.
Sorry.
Anything you do can get you slashdotted, including nothing.
http://maps.google.com/maps?z=19&ll=52.214104,0.09 8791&spn=0.001454,0.005107&t=h
Sweet
I want my own BYOS-kit too! (Build Your Own Spaceship)
They beat guy from Cygnus High Altitude Balloon by almost 3 km. But there was three of them, 11 km for each. Cygnus guy did 28 km alone. So he is over two times better than them :)
:wq
Yes we will be trying a directional GSM antenna on a later flight, just out of interest more than anything else. The results from the radio were so good that we are planning to spend the next couple of flights proving that a GSM phone is not required, that would save considerable mass and money.
"Studies have shown that people who eat peanuts live longer than those who do not eat."
They should have just placed a P4 cpu on that rig to keep it warm, and if it starts getting cold, slow down the fan
or stop it. If the box is well insulated, then the real problem would more likely be TOO much heat that cant
be got ridden off because of the low presure in air. Paint the 'probe' white too btw to reflect the suns heat if its too hot
or black if its too cold.
Liberty freedom are no1, not dicks in suits.
Nasa ages ago used a long long tether to generate power, but it made too much and blew (http://en.wikipedia.org/wiki/Space_tether)
So attach something like that to your rocket, get the power to 'push' yourself somehow using all those megawatts. Strong electro magnets?
Liberty freedom are no1, not dicks in suits.
Tell me one insurance company that can bring people back from the dead, and talking to them doesn't count. Not
that they would say anything usefull, as all ghosts are NOT helpfull and will never reveal the truth/life/everything
about the afterlife, or what they do, if they sleep or not, or if they time travel or if they have a govt of sorts
or leaders that say "you cannot reveal much to living souls"
If a darn ghost was that usefull, Einstein would have told someone the answers too all. Unless they
dont know any more than when they died. But if the soul gets reborn into another human, then
contacting your dead relative might be fruitless as they cannot 'return the call' if they are 3 years old
in a baby somewhere in India, unless they are timeless but then that gets too wierd to imagine.
Liberty freedom are no1, not dicks in suits.
I actually worked in the same lab as these guys, so here's my input: The reason that this was an important launch was not the photos, although those are cool, but to test the electronics of the tracker devices they'dd designed and built. If you read their website at http://www.cuspaceflight.co.uk/ you'll see the other projects - the rocket to space, but also a controllable parachute that can descend to within 100m of a given location. All fairly impressive stuff, given that they've only jsut finished their 1st year of study. As for costs - only a couple of hundred pounds...
It seems on the photos like they recovered their craft with no trouble at all, however wouldn't a such balloon usually land a long way from where it ascended due to jet streams in the atmosphere? They probably tracked the thing well with GPS and could follow it on the ground, however it seems like pure luck that they were able to pick up the craft before someone else found it in a neighbouring state or something?
Manned flight? Already done in 1982.
Space On a Shoestring?
Aren't they going to need something stronger than shoestring for a space elevator?
It's called a rockoon, and it's been used since the earliest days of the space race.
http://www.astronautix.com/lvs/rockoon.htm
"Cornflakes are not the innocent critters they seem"- Sterling Morrison
1) Get an untraceable PAYG mobile
2) Load it onto a remote-controlled plane
3) Fly it around over central London at lunchtime
4) ???
5) Try to explain to Hastur and Ligur exactly how this constitutes
6) Profit!
Real Daleks don't climb stairs - they level the building.
In the research center where I work, one of the guys who had worked on the GSM spec gave a talk on this.
He said that the big problem was that it is very tricky for an airborne phone to decide what cell it's closest to, since it can see loads of them and they're all pretty much the same distance (the downward distance is now very large compared to the on-ground inter-cell distance). This means your phone keeps jumping between cells, which incurs quite a lot of overhead on the network (and if you had a planeload of people doing it, it would be very chaotic!).
I'm sure Dr. Van Allen would be glad to see people continuing to follow in his (impressive) footsteps.
Village idiot in some extremely smart villages.
Bandwidth isn't the issue. It's the server hosting it, that belongs to the Student Run Computing Facility, that is
Check out the fleet of strange craft in shots 63 and 64, and the tentacle examining the balloon in 69!
Maybe they can get something into orbit for the 50th anniversary of Sputnik? They still have a bit more than a year to make it happen.
#naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
Could you have a valve on the balloon to release gas?
a)This might allow you to go higher by releasing a little gas to avoid bursting the balloon.
b)When you want to descend you can just release all the gas and reuse the balloon.
Any chance of more details on how the guidance system works - I tried to build a UAV once with a large kite, picaxe processor and servos but ran into weight and intelligence (mine not the picaxe's) problems. I'm very impressed by the project.
Mike
I don't think Hastur and Ligur really grasps the possibilities.
And I don't think guys like Crowley care about being traced...
In the US, notice/permission to launch ballons such as this can usually be done by calling the nearest FAA ATC facility 6 to 24 hours before beginning the operation and giving them the particulars. The applicable regulation is FAR Part 101. http://www.faa.gov/regulations_policies/faa_regula tions/
Please.
Perhaps life really is full of possibilities.
Bang on right - this is the reason you can't use phones on planes, it causes mayhem for the routing algorithms on the network, as your phone can be seen by literally hundreds of bases.
several other universities have already done similar projects in the past few years.... http://www.engr.uky.edu/news/archives/2005/BIGBLUE IIIlaunch.htm
please tell me uve seen the guys mobile number in the second picture and that someones phoned him and asked if anyones told him he looks like rolf harris?
I'm sure there are a good number of space geeks that could do something similar to this, only more coordinated.
I am sure that all of the fat cats at NASA and other CEOs involved in lucrative contracts (beats working for a living) - are pucking their guts today. On the other hand they all could be trying to figure out how to strap a Cruise missile onto the Brits Space Rocket.
Shazam
At least one of the X-Prize competitors was planning to balloon launch. I'd post their website, but it is no longer "on the air".
When our name is on the back of your car, we're behind you all the way!
Cells phones in general are MUCH less likely to work at high altitude then in years past. Base stations have moved closer together and use antennas that concentrate signals DOWNWARD. They tend to be quite insensitive to signals arriving from high angles.
no text
you had me at #!
that it's easy to forget that /. is still a public forum.
First, let me say congratulations and welcome to the high altitude ballooning community.
In defense of some of the other posts, this has been done in the States for many years. Some of the older groups such as HABET (Iowa State) have been doing just this for over a decade.
Maryland Space Grant will be launching a balloon on September 30th (dates do change due to weather) that will be carrying a number of university built payloads along with digital stills and video. Three transmitters will be providing GPS positions for the entire flight along with digital telemetry downlink. We will be posting directions, in the next week, on how to follow the launch online in real time. For updates, check www.NearSpace.net as it gets closer.
I guy who lives down the street from me, Ky Michaelson, has already done this. In 2004 he launched a home-made rocket to 100 km. He was the first amateur to do it, but it's nice to see these kids getting into the act as well.
I hear just like any 35 year old vehicle they had to fool with the starter to even get the engine to fire http://msnbc.msn.com/id/14705397//, and once it was in orbit parts started falling off http://www.chron.com/disp/story.mpl/ap/nation/4201 025.html/.
I'd jump off a a baloon with a $1200 rocket strapped to my back before I'd go into orbit with that piece of junk.
I've seen very simular problems on mountain top. On top of South Sister in Centeral Oregon (Western US) at 10,350 feet I've seen hapless users try to use their cell phones to no avail. As much as some twit on cell phones in a wilderness area chokes me I told him to just drop off the summit - any direction - and sure enough he was able to connect. His problem was too many cells. Dropping even a few meter below the summit limited his line of sight to a reasonable (and planned for) number of cells.
Just a thought, but putting a pressure valve on the balloon intake hose would allow a higher altitude?
And just a question, at what altitude would an Ion Engine be useful? The I saw a prototype in the 1970's that was half the size of a hand.
Surley you travel faster than 50knts when your on a high speed train or even in a car going down a motorway?
Wow, how about adding room for a passenger, a parachute, and an air tank? I'd pay $3000 for a trip up to the stratosphere!
As for thinking? I totally disagree with you there. Most people don't think AT ALL. Try talking to someone about legalizing pot. Regardless of which side you have, the other person will amost definitely have some knee-jerk reaction and ignore any sort of reason whatsoever. For instance, if you are on the pro-legalization side, talking someone who is against it, they'll ignore any of the following reasonable arguments: pot is not addictive, less physically habituating than even coffee, it's easier for children to get illegal drugs than legal ones (more children smoke pot than cigarettes, for example). I'm sure there are at least a few flimsy arguments the other way, although I've never heard them. Most people you talk to will have a completely emotional response though, and not actually think about any of the facts you provide. Emotion is one of the alternatives to thinking. And it's the main way that people approach the world.
With governments, I do exaggerate somewhat. Still, corrupt, hishonest leadership is by far the most common situation in government of any kind.
Time beomes the issue ... cell towers are designed to have a fixed range ... say 1 mile for example. Your phone will not be able to register with the tower if the rount-trip-time is longer than for the maximum intended range of the tower. I've been out at several miles off the coast with full signal strength but no service because I was too far away to register on the network.
dropping a nuke on all the CA wildfires would put them out but just because it's effective doesn't mean it's not overkill. But yeah planes can't just take off and keep going. The answer is simple: "Beam me up, ISS" *star trek teleporter noise*
Is it just me or is it not going to upgrade to Vista in here?
Some of those shots were up high enough that you could see space, which I assume means the atmosphere is thin enough that it doesn't diffuse the light and such. Can a ballooon really go up into atmosphere that thin??? I've heard of jets that can do that (COO of mine once rode on the Blackhawk :P), but not balloons. Can someone enlighten me?
Love many, trust a few, do harm to none.
Yeah, those radio waves can take a lonnnng time to travel a few miles. :)
But seriously. The problem you had is that your phone could hear the tower but not vice versa. Your phone's signal indicator shows how well the tower signals are received, but says nothing about how well the tower can hear your phone's reply.
FATMOUSE + YOU = FATMOUSE
This is sooooo 20th century...
The Wise adapts himself to the world. The Fool adapts the world to himself. Therefore, all progress depends on the Fool.
Were you using a full GSM phone, or a module? This module weighs 23 grams. There's a variant with a GPS radio included, and some of them also have an on-board python interpreter, so you don't even need a separate microcontroller.
I thought the point of the whole "rockoon" idea was to help the early rockets reach higher altitudes by launching the rocket from a balloon rather than from the ground. Today, sounding rockets can reach the same altitudes without the need to launch from a balloon.
As for people following in Van Allen's footsteps, there is still a group at the University of Iowa that launches sounding rockets. Other schools in the U.S., such as the University of New Hampshire and Dartmouth College, also have research groups that launch sounding rockets on a regular basis. The rockets launched by these groups cost a considerable amount of money, as they have very complicated suites of instruments on board that measure charged particles, magnetic fields, and electric fields. A lot of the work on these sounding rockets is done by graduate students or recent Ph.D. recipients.
The balloon flown by the students in the article seems to have just taken snapshot photos, and did not make any other measurements, such as the temperature, pressure, wind speed, etc. in the upper atmosphere. Even though this sort of thing has been done before and the instrumentation was not terribly complex, it will still give the students valuable experience planning and executing a mission. I think this is the real benefit of their project, not a way of providing low-cost access to space or new scientific data.
I always carry a callphone when flying a cessna 172, and
have often made GSM calls and and sent/received text messages
at 115kts and 5000ft. I get reasonable good reception
most places except over the mountains.
In fact, all private pilots I know of carry cellphones as
a backup communication device.
No compliants from Vodaphone NZ yet.
There Is More Than One Way To Do It (TIMTOWDI)
Everybody knows 3 people with my name.
There will be an ascent Saturday in Northern Colorado. This one is planned to reach "only" 70,000 feet (21km); others by this group have reached over 100,000. Listen for it if you're in UHF radio range.
Cell towers are built with that in mind ... there's little use being able to transmit to a phone if you can't hear it's reply - That's just wasting power. The timing thing is for real, it's how the cell tower knows that you are outside it's designated area.
How can a tower differentiate between the radiowave propagation time (~nanoseconds) versus the processing delays incurred inside the handset (~milliseconds) ?
And why should the tower care? The handset is limited to 0.6W of transmit power, so it will self-limit its own maximum range.
FATMOUSE + YOU = FATMOUSE
Surley you travel faster than 50knts when your on a high speed train or even in a car going down a motorway?
Well, 50kts is about 60mph, so yes, about twice that. However, you can't (generally) see more than a handful of cells at the same time, and they will all be expecting to see the same phone. This is how handoffs work. From a couple of thousand feet, you can see many more cells, some of which aren't expecting to be in range of the same phone.
Wow. That's incredible. Especially this picture! (currently using it for my desktop background)
http://www.moonraker.com.au/techni/cel.htm
The base station regularly sends a signal to the mobile which is echoed back to base and, based on the time taken, the mobile is instructed to advance or retard transmission. Any signals that arrive after the maximum time limit are ignored as being foreign to the cell. For this reason, if there is not another cell to hand the signal on to, the signal drops out at the boundary.
Ah, you're right. I found a patent (6754502) for exactly that.
The patent explains how the towers deal with the uncertainty introduced by the handset's internal processing delay: each phone self-reports its own delay to the tower. I should've known. :)
FATMOUSE + YOU = FATMOUSE
then how exactly all those 9/11 passengers called home about the hijacking? we know they did for a fact, since you cannot fake that many relative's accounts.
Obama likes poor people so much, he wants to make more of them.
then how exactly all those 9/11 passengers called home about the hijacking?
They called after the plane lost altitude. Many of the calls were placed as 2 planes were skyscaper high, not at 35,000 feet. They were in close range of just a few towers and not close to the same strength to towers over a very large geographic area such as 10 miles. At lower altitude, they were considerably closer to some towers than many other towers.
The system works at 800 feet. It has problems at 40,000 feet.
The truth shall set you free!