[request] Someone have a sonic bang wav ?

[DanSteph]

all is in the title... even if it look bad it's just to give me an idea
how to make the sound, I heard it one or two time in my life
but I was young.

Dan

[Orbiter Fan]

Dan, I can e-mail you an enhanced recording of the Shuttle twin-sonic boom if you want. It's not
that good but it's something to base the OrbiterSound boom on.

[ChristopherT]

I have a couple of those double boom .wav files too.  I have a single one also but it's not as
clear.  Let me keep looking.  

   Christopher

[DanSteph]

Yes thanks I have made one already but based on an explosion reworked with  double bang and reverb....

Just to have a look at how it must sound.

Dan

[DanSteph]

Thanks Chris I take them all

Dan

[Orbiter Fan]

Dan, I have now sent you my twin sonic boom sound file. Hope it's to any help.

[ChristopherT]

 Dan, email me at tarana@bluemarble.net and I'll send them to you.  It's a 1.4 meg .rar file
that includes a short mpeg of an F-14 breaking the sound barrier next to the video
camera.  
 
       Christopher

[canadave]

OK, and in searching, I found a video where you can actually SEE the sonic boom!  Plane flies by,
vapour is compressed by the waves, you can see it...absolutely wild!  Check it out:

http://gpsinformation.net/exe/boom.html

By the way, my search is NOT being helped by the fact that there's a band out there called "Sonic
Boom"

Dave

[Pierre, LFPG]

Hi DanSteph!

I have a MP3 file with a sonic Bang from Concorde, it may help! It was recorded from a ship in the
Atlantic Ocean and sounds great!

Pierre, LFPG, STV1010

[DanSteph]

Thanks everyone, to send me just click on "contact" button on the left
it will open your mailer with my adress ready to send.

My e-mail is limited to 25 mo so I think there is no size problem.

Dan

[reekchaa]

I'm sure you already know doing a "sonic boom" quick search on http://www.sounddogs.com has some nice samples.
Hmm.. this f18 snapshot looks amazingly close to the existing particle puffs that we can generate
now, eH?  http://antwrp.gsfc.nasa.gov/apod/ap010221.html
& This little Java Applet might help Build a BOOM, based on ear location http://www.phy.ntnu.edu.tw/java/airplane/airplane.html
and finally.. If you wanna be amazed or amused...  
http://bcornet.homestead.com/files/LynchFT/FT-VA.htm



Post Edited (02-29-04 22:05)

[DanSteph]

Thanks to all I have all the material needed
Some sound are amazing I think they will fit well.

Please be warned (before you get deceived) that making a real sonic boom
from location is an absolute "no no"  it would mean that I record several time by second
the source of the sound (aircraft) and that I "raytrace" all those sound point with complex
calculus to see wich one reach you and when. No need to say that your Orbiter may run
20FPS below what it run usually just for a sonic sound. (and not run at all on lower
machine than mine)

For now I have just a sonic boom that is sent when craft pass mach 1
and the litle fact that it have realistic delay (speed of sound 340ms) make it
look ... unrealistic.  Due to view distortion or whatewer in Orbiter the sound *seem* to
come incredibly late (a distance of only 10 km make a delay of 30 second wich seem
incredibly long in Orbiter) So I seriously thing to "speed up" the speed of sound
or to null it.

Also usually aicraft flight somewhat straight when in supersonic speed while in Orbiter
I'm sure you will make a lot of flyby around a ground observer, in this case the real
behaviour is to hear several time the hypersonic bang.... not really appealing.

Anyway the way it work *now* in my code you will have hypersonic bang after
the lift off of the shuttle (don't tested but I think at 10km alt) and you may have one
also when the shuttle slow down below mach 1 if your a ground observer.
In flyby you will have one when the craft pass mach 1 and when it slowdown below
mach 1.
I think our brain is waiting that more then several bang as if it was the war in Orbiter.
(also don't forget the 20fps it may take in calculus)

Graphist or sound effect maker in film know that: sometime the reality sound less
real than faked things... (80% of film we watch are totally unrealistic the other
are often qualified as "boring"

Anyway many thanks again for the material.

Dan

[DanSteph]

Reechka: Ufo subject is a sensible one to me also

to quote someone: "the best proof that there is intteligent life in
the universe is that they never tried to approach us"

I'm the one to be SURE that there is other hinabited planet
in the universe, statistically it's almost impossible that there is no life
elesewhere, anyway  the relativity (travel time) render contact almost
impossible.

And if they did find a way to travel at greater speed than light, why
come here ? it make 200 years only that we send radio wave.
I was loving those story when I was young but now it seem
that 99% of them are incredibly dumb....

Logically & scientifically  ther is life elsewhere but logically also they
didn't come on earth.
(my damn english , why you all don't learn french so we can discuss ?

I put ufo story in the same bag than "faked moon land" "astrology" and
some *others* things that some(many?) men believe ....

Die hard science here

(I always wonder why men need always incredible fake story to feel well,
the simple fact how the universe is is thousand time more marvelous)
(perhaps it's because THIS universe don't turn around us ??

Dan

[MattNW]

I don't think it has to be perfect. A sonic boom is something that is mostly only experienced by an
observer. The crew on supersonic aircraft don't experience it the way a person on the ground
would. Since the viewpoint of the observer is limited then a simple delay when the ship flys past
before the sonic shockwave hits would be realistic enough. An observer wouldn't have the
knowledge of the instruments so the length of delay wouldn't be apparent except only as a very
general thing (ie, ship flys by, wait a second and then BOOM!). The exact timing wouldn't be
known unless the observer had detailed real time telemetry from the ship.

That is an interesting observation about the condensation effect. I wonder if it couldn't be worked
into the DG III or even all the ships in general. It'd make some cool screen shots if it could. I got a
chance to observe the phenomenon this summer at the Indy Airshow in Indianapolis IN while
watching the Blue Angels performing. Quite impressive.

Can't find the picture on their site anymore but I saved it when they did have it up.

Indy airshow: http://www.indyairshow.com

[reekchaa]

Funny how they always look the same.  A boom is a boom, eh?  Cloud creates & dissipates.

a rapid cone dispersal of particles just before (or at) the 'boom' sound would be delicious.

[DanSteph]

The smoke may be intteresting for a DGIII howewer I'm in sound now

I just achieved the *exact* effect as showed in your video:
silent until the aircraft flyby in front of you then sonic boom and reactor
sound back... amazing !

But BAD THINGS this may be only a programmer "behind the scene"
experience as I may discard it for various reason (one of them is that
I must calculate myself the delta speed of the ship/camera and Orbiter
return an innacurate delta time so the speed vary constantly about +/- 20ms)
And also for others problems.

Off topic but fun about "programmer behind the scene" experience:
this recall me when I implemented sea bird in my sail sim: there was
something wrong with their AI and they never returned to fly around
you after a while so I mounted a camera on the sea bird's head to see
where those sea bird did going....

Amazing because as they flapped with their wing the camera moved up/down
also.... So I visited "my world" on the top of a bird LOL

Well, err... mhh.. lets return to code.. damn I'm not satisfied

Dan

[MattNW]

That doesn't sound like that much variation to me. If I understand the way a sonic wave works the
faster the ship is flying when it passes the longer the delay will be between flyby and hearing the
shockwave. The delay of +/-20ms would only be a knot or two difference in speed. To an outside
observer that wouldn't even be noticeable.

I haven't studied it in depth but that seems quite acceptable. I doubt that any normal person
would notice if a jet passed by and the sonic boom was just a few milliseconds later than it should
be.

Actually when I suggested a sonic boom I wasn't invisioning anything more than just a "BOOM"
sound when the ship passed Mach 1 but since someone mentioned the idea I thought it would be
even cooler to have the ship pass in silence and then a boom since I've seen jets do that but the
exact timing isn't going to be too apparent either way.



reekchaa:

 I think the reason they look so similar is due to the aerodynamics of the aircraft. If you'll notice
both pictures are of F-15s which have similar aerodynamics although one has a load and the other
is clean. The position of the shockwave is very carefully calculated in designing the jet so two
similar airframes will produce similar condensation effects. Actually it was this effect that led to so
many lost pilots back before they finally broke the sound barrier. Supersonic aerodynamics is a
precise art so each airframe will have it's own characteristic shockwave as the airplane
approaches the speed of sound.

Actually the condensation effect (I think it's called a Q wave) is somewhat rare to see. It takes
certain meterlogical conditions for it to appear in it's visible form.


NOOOO! DAN!! STOP!! (Dan = )  I'm not suggesting that we calculate the atmospheric
composition and decide whether it's correct for a Q wave condensation. Just something I picked up
reading about it last summer.

[ChristopherT]

MattNW wrote:

>  I think the reason they look so similar is due to the
> aerodynamics of the aircraft. If you'll notice
> both pictures are of F-15s which have similar aerodynamics
> although one has a load and the other
> is clean.
  Uh, Matt?  I'm only Ex-NYANG, but aren't those F-18 Hornets?  

 The position of the shockwave is very carefully
> calculated in designing the jet so two
> similar airframes will produce similar condensation effects.
> Actually it was this effect that led to so
> many lost pilots back before they finally broke the sound
> barrier. Supersonic aerodynamics is a

 When Chuck Yeager and Bob Hoover were flying the X-1, Chuck recounts an incident when he
was flying at .97-.98 Mach and the elevators refused to pitch the aircraft.  He slowed down and
the controls returned to normal.  When he flew at Mach .98 again the elevators locked up again.
  He slowed down and landed at Edwards and the slide-rule guys went over the telemetry data
during the night.  It turned out that the shockwave was balanced right on the elevator hinges
and not allowing the elevator to move, so they spent the next few days ground testing the
trim system to see if moving the whole stabilizer would allow Chuck to fly up to .99 Mach.  On the
next flight when he got to .98 Mach and the elevators locked up, he was able to use the trim to
control the aircraft while he pushed the speed up to .99.

    (Yeager by Yeager)


             Christopher

[Arkalius]

Remember, the smoke doesn't happen at the "boom", it happens when the plane crosses the
sound barrier (either speeding up or slowing down).

[DocHoliday]

*Doc sits in wonder at the compex Q wave and sonic boom discussion*

You'ssa think'n lotsa. Me'ssa just a barely being able to follow what you'ssa sayin'. Me'ssa thinka
you'ssa sooo smartee!

kidding. I'm learning new stuff here. Carry on.

[David Smit -- davidsmit]

Sounds like a good idea, Dan! Sorry, couldn't resist... Or help you with the file... GREAT SHIP!!
I don't know  if a visible boom would add very much to the ship.

David Smit

[DanSteph]

what is really odd and that some may don't know is that the bang is continuous it's not only when you pass the sonic barrier at mach 1.
You ear it when the shockwave reach you.

This is why the bang in OrbiterSound will be a complete fake as the sound
play when the ship pass mach 1. There is no coding way to calcul the real
shokwave unless Orbiter become a "sonic bang" sim that run at 10 FPS.

Anyway it doesn't look to bad yet. IT ***sound*** somewhat as real
(at least the sound is really cool)

I'll add an option to disable it for some that don't like fake stuff.

Dan

[reekchaa]

What's really bizarre is that you hear the sound which happened later, and THEN hear the sound
which happened earlier.  It's loudest when these times overlap.  Great applet tool to explain...
http://www.phy.ntnu.edu.tw/java/airplane/airplane.html

[DanSteph]

Sound logicall to me the sound travel at 330m/s

Dan

[Arkalius]

The sonic boom effect is kind of strange. It will be silent until you hear the boom, but then the
sound you hear after that will appear to be coming from the direction of the plane, as well as from
where the plane came from awhile back. You actually hear both the delayed current sound of the
plane mixed with the past sound of the plane in reverse. It's a very strange phenomenon.