Most probably using either LIDAR at a sufficiently small (non-visible) wavelength (quite susceptible to atmospheric effects), or RADAR -- _much_ smaller wavelength, therefore higher potential resolution. IIRC both these technologies are used to collect elevation info.
Was the receiver new? Often, with a new GPS unit, the first time it is used when new (or after not being used for a long time), it will need to refresh it's ephemeris and almanac data, and determine just where it is. Especially if, say, you buy a Garmin, and you live in Australia. The last time the GPS receiver looked, it was in Kansas, now it doesn't know _where_ it is. I've seen the little GPS-12 OEM boards take 3 or 4 hours to initialise the first time. (I'm nowhere _near_ Kansas).
If you want to see a _real_ flying toilet seat, look for the Cypher, the Dragon Warrior's predecessor.
Re:Another book on the topic...
on
Enigma
·
· Score: 2, Informative
I found 'Codebreakers - the inside story of Bletchley Park" (Hinsley & Stripp) pretty good. It is best read in concert with the Enigma chapters in Singh's 'The Code Book', though, as they leave the technical description of Enigma 'till fairly late in the book, so in some of the early chapters you have _no_ idea what they're talking about until you skip forward a bit.
My 'Yuck' was mainly due to the fact that it's physically nasty to work with - ie. the fume factor, (and the 'goo factor), and sometimes it's curing is somewhat unpredictable (mainly due to going off while you're working with it). Epoxy does have somewhat better mechanical properties (if your application demands it), and you can generally tailor the cure to your needs (most epoxies have different hardeners for different tasks). Also you can get epoxies with _very_ low viscosity (almost like water) for tricky jobs. Epoxy _is_, however, even nastier than polyester chemically (physiologically), and is _way_ more expensive.
You could always use that as a 'plug' (male model) from which to make a female mold (out of glassfibre or plaster). You can then make a thin shell casing from the female mold, in glassfibre or carbon (looks _very_ cool).
Hydrocal is a hard plaster/cement type compound that works _really_ well for short run molds, or for one-off parts, generic plaster works well. If the shape is complex, eg. has undercuts, then you'll need to make the mold from silicone. Check out Special Effect Supply, they seem to stock a lot of the stuff.
Once you have the mold, you can then lay up a part using polyester (Yuck!) or epoxy resin and glass, carbon or kevlar fabric. Glass fabrics are now also available in colors (I've seen red, silver and blue) if you don't want to paint the final part. Another option is to cast the part using a polyurethane resin, (try ProCast ) You will probably have to make a multi-part mold in order to define a wall thickness, though.
There are _much_ more elegant ways to do this (eg. CNC machining), but molded glass or polyurethane is probably about the easiest / cheapest method of prototyping this sort of thing. With a bit of effort, you can get _really_ professional looking results.
I fly R/C Sailplanes, and this is great not only for getting outdoors, but also involves (If you so choose) a fair bit of theoretical work (Aerodynamics, structures, etc), _and_ getting your hands dirty with building (Either wood, or for the fancy stuff, carbon fiber, kevlar, etc.). Also some electronics and software (if you use one of the neat computerized radios). And can fulfil the _need_for_speed_. (The world speed record for R/C sailplanes is around 390 Km/h -- 243 mph).
Actually, the _default_ Tk look and feel sucks rocks.
However -- the nice thing about Tk is that the widgets are _extremely_ customisable. A bit of tweaking of the widget options and you can make it look pretty much like anything. (Obviously within reason -- you can't change widget shapes, ferinstance).
All my Tk apps, for example, have the JFC/Swing 'Metal' look 'n feel, for a bit of consistency across Java and Tcl/Tk apps.
At first glance, this looks pretty straightforward.
There is always the issue though - how much is your time worth? Can you afford the time to develop (and debug) something like this from scratch, or would it be simpler (& cheaper in the long run) to use a commercial, turnkey solution?
If you figure it _is_ worth developing from scratch - here's what I'd use:
Linux, with a fairly recent kernel (nice BT8x8 vidcap drivers), an el cheapo video capture card (or more), 'streamer' frame capture software (infinitely configurable for framerate, size, etc), 'XawTV' for live viewing, and a whole bunch of 'glue' code (my preference is Tcl/TK), -- and Bob's yer uncle.
IIRC Vectran is a 'Liquid Crystal Polymer' fibre, quite frequently mentioned during the last two(?) or so America's Cup events. Seems to mainly be used in competition sails.
Uh, I haven't seen any reports on Raven construction in quite a few years, but generally when they talk 'paper honeycomb'they mean Nomex.
Nomex is a (IIRC) Meta-Aramid fibre, same family as kevlar. Nomex is used for fireproof articles (coveralls, like racing drivers use, etc.), and also made into a honeycomb. Believe me - if you've had to _work_ with Nomex honeycomb, you'll understand it is _nothing_ like paper as we know it;-)
With a normal V-tail, when rudder input is used, the required control deflection produces the correct yaw moment, but an *opposite* rolling moment (adverse roll), which fights the aileron (roll) input required to initiate the turn.
An inverted Vee (sometimes known as a lambda or 'A' tail), produces a rolling moment in the same direction as the yaw, helping roll the aircraft into the turn.
This seems to be quite popular in UAVs, eg. Aerosonde and a few others (whose names escape me right now....)
Well - one thing that comes to mind is *no tether*. A > 100 000ft long tether (or rather a whole bunch of them) could tend to get in the way now and again.
Slashdot Mirror
Reminds me of DNS LOC
Also, check out RFC 1876 - A Means for Expressing Location Information in the Domain Name System
How about This?
(Look for 'Thunderwell').
Maybe not, but makes for a neat story, though!
Most probably using either LIDAR at a sufficiently small (non-visible) wavelength (quite susceptible to atmospheric effects), or RADAR -- _much_ smaller wavelength, therefore higher potential resolution. IIRC both these technologies are used to collect elevation info.
Also, try the Perry-Castañeda Library at UTexas. - a good collection of both
vintage _and_ current interest / events related maps.
Mmm. A bus with forty _lawyers_ on board (preferably entertainment industry lawyers).
Now _that_ would be a _good start_.....
Was the receiver new?
Often, with a new GPS unit, the first time it is used when new (or after not being used for a long time), it will need to refresh it's ephemeris and almanac data, and determine just where it is. Especially if, say, you buy a Garmin, and you live in Australia. The last time the GPS receiver looked, it was in Kansas, now it doesn't know _where_ it is.
I've seen the little GPS-12 OEM boards take 3 or 4 hours to initialise the first time. (I'm nowhere _near_ Kansas).
Erm. seems someone has the _wrong_ Dragon Warrior.
Look Here
If you want to see a _real_ flying toilet seat, look for the Cypher, the Dragon Warrior's predecessor.
I found 'Codebreakers - the inside story of Bletchley Park" (Hinsley & Stripp) pretty good.
It is best read in concert with the Enigma chapters in Singh's 'The Code Book', though, as they leave the technical description of Enigma 'till fairly late in the book,
so in some of the early chapters you have _no_ idea what they're talking about until you skip forward a bit.
Mmm..
Here is a link to an interesting article on the fine-structure constant, and Sir Arthur's related exploits (5th para on).
My 'Yuck' was mainly due to the fact that it's physically nasty to work with - ie. the fume factor, (and the 'goo factor), and sometimes it's curing is somewhat unpredictable (mainly due to going off while you're working with it).
Epoxy does have somewhat better mechanical properties (if your application demands it), and you can generally tailor the cure to your needs (most epoxies have different hardeners for different tasks). Also you can get epoxies with _very_ low viscosity (almost like water) for tricky jobs.
Epoxy _is_, however, even nastier than polyester chemically (physiologically), and is _way_ more expensive.
You could always use that as a 'plug' (male model) from which to make a female mold (out of glassfibre or plaster).
You can then make a thin shell casing from the female mold, in glassfibre or carbon (looks _very_ cool).
Hydrocal is a hard plaster/cement type compound that works _really_ well for short run molds, or for one-off parts, generic plaster works well. If the shape is complex, eg. has undercuts, then you'll need to make the mold from silicone. Check out Special Effect Supply, they seem to stock a lot of the stuff.
Once you have the mold, you can then lay up a part using polyester (Yuck!) or epoxy resin and glass, carbon or kevlar fabric. Glass fabrics are now also available in colors (I've seen red, silver and blue) if you don't want to paint the final part. Another option is to cast the part using a polyurethane resin, (try ProCast
)
You will probably have to make a multi-part mold in order to define a wall thickness, though.
Maybe check out FibreGlast for some ideas.
There are _much_ more elegant ways to do this (eg. CNC machining), but molded glass or polyurethane is probably about the easiest / cheapest method of prototyping this sort of thing. With a bit of effort, you can get _really_ professional looking results.
I agree totally.
I fly R/C Sailplanes, and this is great not only for getting outdoors, but also involves (If you so choose) a fair bit of theoretical work (Aerodynamics, structures, etc), _and_ getting your hands dirty with building (Either wood, or for the fancy stuff, carbon fiber, kevlar, etc.). Also some electronics and software (if you use one of the neat computerized radios). And can fulfil the _need_for_speed_.
(The world speed record for R/C sailplanes is around 390 Km/h -- 243 mph).
Check Here for some info.
Actually, IIRC, ROX-filer is entirely C. It _does_ provide some sort of hooks for writing extensions or desktop panel applets in Python, though.
Actually, the _default_ Tk look and feel sucks rocks.
However -- the nice thing about Tk is that the widgets are
_extremely_ customisable. A bit of tweaking of the widget options and you can make it look pretty much like anything.
(Obviously within reason -- you can't change widget shapes, ferinstance).
All my Tk apps, for example, have the JFC/Swing 'Metal' look 'n feel, for a bit of consistency across Java and Tcl/Tk apps.
Mmm.....
To carry an analogy to the extreme:
Who remembers the _second_ person to climb mount Everest?
How about the _second_ person to break the sound barrier?
The character you are probably thinking of is "Gustave (sp?) Whitehead (Weisskopf)" a German immigrant in the US, somewhere in the North-East, IIRC.
He apparently flew (manned, controlled, and powered,) in 1901.
See here.
At first glance, this looks pretty straightforward.
There is always the issue though - how much is your time worth?
Can you afford the time to develop (and debug) something like this from scratch, or would it be simpler
(& cheaper in the long run) to use a commercial, turnkey solution?
If you figure it _is_ worth developing from scratch - here's what I'd use:
Linux, with a fairly recent kernel (nice BT8x8 vidcap drivers), an el cheapo video capture card (or more),
'streamer' frame capture software (infinitely configurable for framerate, size, etc),
'XawTV' for live viewing, and a whole bunch of 'glue' code (my preference is Tcl/TK),
-- and Bob's yer uncle.
IIRC Vectran is a 'Liquid Crystal Polymer' fibre, quite frequently mentioned during the last two(?) or so America's Cup events.
Seems to mainly be used in competition sails.
Uh.. found a link:
Vectran fibres
Karma be damned.
Listening to these fucking insane rants posted here, I'm just thankful I'm not american.
Fucking arrogant Yanks.
Welcome to the _real_ world.
Actually, NeXTSTEP also ran on all architectures (x86, HP, Sparc and NeXT Motorola) - from v3.0 up, IIRC.
As for the 'feel' - definitely.
'Back in the day' I ran NeXTSTEP 3.2 on a 486/66, and it was *dog* slow compared with a NeXT cube (25 MHz 68040).
Uh, I haven't seen any reports on Raven construction in quite a few years, but generally when they talk 'paper honeycomb'they mean Nomex. ;-)
Nomex is a (IIRC) Meta-Aramid fibre, same family as kevlar. Nomex is used for fireproof articles (coveralls, like racing drivers use, etc.), and also made into a honeycomb. Believe me - if you've had to _work_ with Nomex honeycomb, you'll understand it is _nothing_ like paper as we know it
I already get a headache watching rugby on TV.
So what's new ?
Actually, I'd better keep my mouth shut.
As a white South African male I could be lynched for dissing rugby in public....
With a normal V-tail, when rudder input is used, the required control deflection produces the correct yaw moment, but an *opposite* rolling moment (adverse roll), which fights the aileron (roll) input required to initiate the turn.
An inverted Vee (sometimes known as a lambda or 'A' tail), produces a rolling moment in the same direction as the yaw, helping roll the aircraft into the turn.
This seems to be quite popular in UAVs, eg. Aerosonde
and a few others (whose names escape me right now....)
Well - one thing that comes to mind is *no tether*.
A > 100 000ft long tether (or rather a whole bunch of them)
could tend to get in the way now and again.
Uh.. actually, that is *almost* one of the proposed
uses for these things. Check out:
SkyTower Telecommunications
or
AeroVironment