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Message no. 1
From: Helge_DiernÊs <hedi93ac@*******.ECON.CBS.DK>
Subject: Ultrasonic underwater?
Date: Mon, 26 Aug 1996 20:15:22 +0200
Hi folks,

Excuse the fussy subject line, but I do as usual have a question;

if I want a submerged diver to be able to pinpoint exactly the spot
where something or someone above water is put or standing, would some
ultrasonic goggles do the trick, that is, ignoring light distortion?
Or does something special have to be developed....

--
Regards,

Sil
Message no. 2
From: Mike Elkins <MikeE@*********.com>
Subject: Ultrasonic underwater? -Reply
Date: Mon, 26 Aug 1996 14:28:13 -0500
AFAIK, the water/air boundary reflects soundwaves very well. As a result, it would
look like a mirror to ultrasonic goggles, assuming they could function underwater
at all (which has a very different speed of sound etc. than air).

Radar might work (from a depth of only a few feet at least).

Maybe someone else might have some better ideas...

Double-Domed Mike
Message no. 3
From: GRANITE <granite@**.net>
Subject: Re: Ultrasonic underwater?
Date: Mon, 26 Aug 1996 13:41:53 -0700
> if I want a submerged diver to be able to pinpoint exactly the spot
> where something or someone above water is put or standing, would some
> ultrasonic goggles do the trick, that is, ignoring light distortion?
> Or does something special have to be developed....
> Well there are a number of possiblilities..Radar, Sonar, Some kind of Laser
finder sort of gizmo..I would simply create a varient of the UltraSonic
Goggle that only operates correctly under water..The normal varient would not
necessarily be water proofed and as someone else said sound travels at
differing speeds through water..The UltraSonic Goggles V2.1 could be water
proof to a predetermined depth and be able to compensate for the speed
changes by water temperature variations..that is the simplest way to fix your
problem IMHO...
--
-------------------------------GRANITE
=================================================================
Lord, Grant Me The Serinity To Accept The Things I Cannot Change,
The Courage To Change The Things I Can,
And The Wisdom To Hide The Bodies Of Those People I Had To Kill
Because They Pissed Me Off.
~~~~~~~~~~~~~~ShadowRunner's Serinity Prayer
Message no. 4
From: "Paul J. Adam" <shadowrn@********.demon.co.uk>
Subject: Re: Ultrasonic underwater?
Date: Mon, 26 Aug 1996 19:44:28 +0100
<hedi93ac@*******.ECON.CBS.DK> writes
>Hi folks,
>if I want a submerged diver to be able to pinpoint exactly the spot
>where something or someone above water is put or standing, would some
>ultrasonic goggles do the trick, that is, ignoring light distortion?

Nope. Sound doesn't leave water at all well and it wouldn't be
effective. Looking at the surface with ultrasound goggles would give you
a horrible headache very quickly (the effects of surface reflection on
HF sonar can only be described as interesting)

>Or does something special have to be developed....

Definitely. A periscope, perhaps? :)


--
"There are four kinds of homicide: felonious, excusable, justifiable and
praiseworthy."
Ambrose Bierce, "The Devil's Dictionary"
Paul J. Adam paul@********.demon.co.uk
Message no. 5
From: Peter Leitch <pleitch_hpcs@*******.com.au>
Subject: Re: Ultrasonic underwater?
Date: Tue, 27 Aug 1996 16:46:05 +1000
At 20:15 26/08/96 +0200, Helge Diernæs wrote:
>Hi folks,
>
>Excuse the fussy subject line, but I do as usual have a question;
>
>if I want a submerged diver to be able to pinpoint exactly the spot
>where something or someone above water is put or standing, would some
>ultrasonic goggles do the trick, that is, ignoring light distortion?
>Or does something special have to be developed....

Ultrasound wouldn't work; I think the defraction caused by leaving the=
water,
bouncing off the target and entering the water again would fuzz up the
signal too much to allow anything to be pinpointed. I mean, ultrasonics
underwater is sonar, right? Have you heard of a sub locating a plane by
sonar? Never; only by radar or visual sighting. If the object to be=
located
was touching the water, and the ultrasonic goggles were waterproof and
calibrated for underwater work, then yes you could pinpoint the object,
not otherwise.
PML

***************************************
Peter Leitch
<pleitch_hpcs@*******.com.au>
Canberra, Australia
Message no. 6
From: "Mark Steedman" <M.J.Steedman@***.rgu.ac.uk>
Subject: Re: Ultrasonic underwater?
Date: Tue, 27 Aug 1996 11:21:45 GMT
Helge Diernees writes
>
> Excuse the fussy subject line, but I do as usual have a question;
>
> if I want a submerged diver to be able to pinpoint exactly the spot
> where something or someone above water is put or standing, would some
> ultrasonic goggles do the trick, that is, ignoring light distortion?
> Or does something special have to be developed....
>
Basically any attempt to propogate some sort of signal throught the
air/water interface will cause you loads of problems. Your problem is
refraction at the surface, this is why goldfish are so difficult to
catch, due to refraction they appear to you to be somewhere they are
not, put your arm in a bucket of water and from the side it appears
to bend at the surface. Doesn't really matter what you try you will
have horrible problems with this. If you want to target things above
the surface you best bet is a periscope, or a comms link with a
remote tracking device [above the surface] (but if you want that sort
of stuff you'll get milspec very very fast). Otherwise you'll be
inaccurate at best, assuming you even get a signal through the water
surface and back.

Mark
Message no. 7
From: Helge_DiernÊs <hedi93ac@*******.ECON.CBS.DK>
Subject: RE: Ultrasonic underwater?
Date: Wed, 28 Aug 1996 00:15:13 +0200
>
>>if I want a submerged diver to be able to pinpoint exactly the spot
>>where something or someone above water is put or standing, would some
>>ultrasonic goggles do the trick, that is, ignoring light distortion?
>>Or does something special have to be developed....
>
>Ultrasound wouldn't work; I think the defraction caused by leaving the
>water,
>bouncing off the target and entering the water again would fuzz up the
>signal too much to allow anything to be pinpointed. I mean,
>ultrasonics
>underwater is sonar, right? Have you heard of a sub locating a plane
>by
>sonar? Never; only by radar or visual sighting. If the object to be
>located
>was touching the water, and the ultrasonic goggles were waterproof and
>calibrated for underwater work, then yes you could pinpoint the object,
>not otherwise.

Hrm, so the advice of my erstwhile contributors is to utilize a
periscope or some comlink.....
Fuzzy. What I need is basically to have a diver equipped with some
special sighting device and a powerful harpoon to be able to shoot a
harbour guard from 3 meters below surface in a standard Londonian
twilight.
As light ampfl is worth nada as light corrector, thermographic should be
mighty unco-operative and ultrasonic won't work, it seems that my only
option is either to invent some seriously advanced tech - think of all
these surface ripples and their effects on light distortion - or simply
present my man with a target number modifier which can be felt - like
+4.

Well, can't be helped. Thanks for the input, fellas :)

--
Regards,

Sil
>
>
Message no. 8
From: GRANITE <granite@**.net>
Subject: Re: Ultrasonic underwater?
Date: Thu, 29 Aug 1996 22:43:02 -0700
> Fuzzy. What I need is basically to have a diver equipped with some
> special sighting device and a powerful harpoon to be able to shoot a
> harbour guard from 3 meters below surface in a standard Londonian
> twilight.

Why does the diver need a special sighting device??? Put a light source
behind the careless guard [After all he isn't paying enough attention to the
shapes moving around in the water] and clean up the water so that it is
clear..There should not be any problems spotting the guard as well as
shooting him/her with a harpoon provided it has enough power behind it...To
poke the guy to death..Afterall haven't you ever gone swimming and looked up
at the people standing around through a diving mask lens??? I am fairly
certain I could pick one of those people off with the appropriate weapon..How
about you??? I realise this is a low tech solution but it also saves you from
creating a new piece of equipment that could be used against you some time in
the future.. :)
--
-------------------------------GRANITE
=================================================================
Lord, Grant Me The Serinity To Accept The Things I Cannot Change,
The Courage To Change The Things I Can,
And The Wisdom To Hide The Bodies Of Those People I Had To Kill
Because They Pissed Me Off.
~~~~~~~~~~~~~~ShadowRunner's Serinity Prayer
Message no. 9
From: Helge_DiernÊs <hedi93ac@*******.ECON.CBS.DK>
Subject: RE: Ultrasonic underwater?
Date: Mon, 2 Sep 1996 18:37:54 +0200
>From: GRANITE[SMTP:granite@**.net]
>
>> Fuzzy. What I need is basically to have a diver equipped with some
>> special sighting device and a powerful harpoon to be able to shoot a
>> harbour guard from 3 meters below surface in a standard Londonian
>> twilight.
>
[snip]

>Afterall haven't you ever gone swimming and looked up
>at the people standing around through a diving mask lens??? I am fairly
>
>certain I could pick one of those people off with the appropriate
>weapon..How
>about you???

Well, I've been diving quite a lot in my youth, but I've not actual
experience with estimating how a person is stationed vertically when i'm
under water :)

> I realise this is a low tech solution but it also saves you from
>creating a new piece of equipment that could be used against you some
>time in
>the future.. :)

Crude tech is totally cool if it works - do you have any TN mod advive?

--
>Helge
Message no. 10
From: GRANITE <granite@**.net>
Subject: Re: Ultrasonic underwater?
Date: Mon, 02 Sep 1996 21:33:25 -0700
Helge_Diernæs wrote:
> Well, I've been diving quite a lot in my youth, but I've not actual
> experience with estimating how a person is stationed vertically when i'm
> under water :)
> Crude tech is totally cool if it works - do you have any TN mod advive?

I used to check out the women relatively unobserved from a submerged
position..What can I say I was a walking/swimming hormone.. :)
Anyway..With a little prepatory practice a PC should be able to take out
a stationary NPC with say a straight +2 visibility modifier as for mist
with the excemption Of for lowlight +2/+2 and Thermo +2/+2. I would keep
this all the way across in order to account to refraction rippling and
waves..Also In the event of turbidity in the water I would treat it as
smoke on the visibility table..wether light or heavy would depend on the
turbidity of the water...
--
-------------------------------GRANITE
=================================================================
Lord, Grant Me The Serinity To Accept The Things I Cannot Change,
The Courage To Change The Things I Can,
And The Wisdom To Hide The Bodies Of Those People I Had To Kill
Because They Pissed Me Off.
~~~~~~~~~~~~~~ShadowRunner's Serinity Prayer
Message no. 11
From: Robert Watkins <robertdw@*******.net.au>
Subject: Re: Ultrasonic underwater?
Date: Tue, 3 Sep 96 19:59:22 +1100
>Why does the diver need a special sighting device??? Put a light source
>behind the careless guard [After all he isn't paying enough attention to the
>shapes moving around in the water] and clean up the water so that it is
>clear..There should not be any problems spotting the guard as well as
>shooting him/her with a harpoon provided it has enough power behind it...To
>poke the guy to death..Afterall haven't you ever gone swimming and looked up
>at the people standing around through a diving mask lens??? I am fairly
>certain I could pick one of those people off with the appropriate
>weapon..How
>about you??? I realise this is a low tech solution but it also saves you
>from
>creating a new piece of equipment that could be used against you some time
>in
>the future.. :)

A little experiment, Granite: Stick a rod, or stick, into a pool, and
look at it BEND... unless you are extremely familiar with the situation,
over a distance of 3 meters, you're so likely to miss as to forget about
it.


--
_______________________________________________________________________
/ \
| "As soon as we started programming, we found to our surprise that it |
| wasn't as easy to get programs right as we had thought. Debugging |
| had to be discovered. I can remember the exact instant when I |
| realized that a large part of my life from then on was going to be |
| spent in finding mistakes in my own programs." -- Maurice Wilkes |
| Robert Watkins robertdw@*******.com.au |
\_______________________________________________________________________/
Message no. 12
From: GRANITE <granite@**.net>
Subject: Re: Ultrasonic underwater?
Date: Tue, 03 Sep 1996 22:49:04 -0700
Robert Watkins wrote:
> A little experiment, Granite: Stick a rod, or stick, into a pool, and
> look at it BEND... unless you are extremely familiar with the situation,
> over a distance of 3 meters, you're so likely to miss as to forget about
> it.
>

Yes, I know all about refraction and all that bending of light waves..I also
sugested that the PCs practice this tactic before they need to use it..Thus a
+2 visual target modifier for lowlight and thermo..Which if you check are
different for a normal oxy environment...If the PCs do not practice this
maneuver I would give them a +4 to account for the lack of practical
knowledge..I have [When I was young and trying to impress the young ladies]
popped out of the water directly in front of the girl who had my attention at
that time...It took only a short time before I was profficient at this
maneuver..So IMHO i believe with a little practice a PC should be able to
fire a weapon and take out a target on the land..If he were to fire a spear
with a cord attached..The guard could be drawn right into the water the
instant after he got hit in order to conceal the body...
--
-------------------------------GRANITE
=================================================================
Lord, Grant Me The Serinity To Accept The Things I Cannot Change,
The Courage To Change The Things I Can,
And The Wisdom To Hide The Bodies Of Those People I Had To Kill
Because They Pissed Me Off.
~~~~~~~~~~~~~~ShadowRunner's Serinity Prayer
Message no. 13
From: "Sascha Pabst" <Sascha.Pabst@**********.Uni-Oldenburg.DE>
Subject: Re: Ultrasonic underwater?
Date: Mon, 9 Sep 1996 20:52:41 +0000
On 3 Sep 96 at 22:49, GRANITE wrote:
[snip]
>.I have [When I was young and trying to impress the young ladies]
> popped out of the water directly in front of the girl who had my attention at
> that time...It took only a short time before I was profficient at this
> maneuver..
Hm... do you mean bumping into 'em or NOT bumping into them? :-)

Sascha
--
+---___---------+----------------------------------------+--------------------+
| / / _______ | Jhary-a-Conel aka Sascha Pabst |The one who does not|
| / /_/ ____/ |Sascha.Pabst@**********.Uni-Oldenburg.de| learn from history |
| \___ __/ | | is bound to live |
|==== \_/ ======| *Wearing hats is just a way of life* | through it again. |
|LOGOUT FASCISM!| - Me | G. Santayana |
+------------- http://www.informatik.uni-oldenburg.de/~jhary -----------------+
Message no. 14
From: GRANITE <granite@**.net>
Subject: Re: Ultrasonic underwater?
Date: Mon, 09 Sep 1996 17:51:10 -0700
Sascha Pabst wrote:
> > ......It took only a short time before I was profficient at this
> > maneuver..
> Hm... do you mean bumping into 'em or NOT bumping into them? :-)


Well, that all depended on what approach was deemed appropriate at the time
:) ..Of course if the young lady was trying to combat a tan line the
objective was to dump as much cold water on her as possible in order to get
them to react by jumping up and of course leaving their bikini top lying by
the pool... ;)
--
-------------------------------GRANITE
=================================================================
Lord, Grant Me The Serinity To Accept The Things I Cannot Change,
The Courage To Change The Things I Can,
And The Wisdom To Hide The Bodies Of Those People I Had To Kill
Because They Pissed Me Off.
~~~~~~~~~~~~~~ShadowRunner's Serinity Prayer
Message no. 15
From: Helge_DiernÊs <hedi93ac@*******.ECON.CBS.DK>
Subject: RE: Ultrasonic underwater?
Date: Tue, 10 Sep 1996 15:26:56 +0200
>From: GRANITE[SMTP:granite@**.net]
>Sent: 10. september 1996 02:51
>Sascha Pabst wrote:
>> > ......It took only a short time before I was profficient at this
>> > maneuver..
>> Hm... do you mean bumping into 'em or NOT bumping into them? :-)
>
>
>Well, that all depended on what approach was deemed appropriate at the
>time
>:) ..Of course if the young lady was trying to combat a tan line the
>objective was to dump as much cold water on her as possible in order to
>get
>them to react by jumping up and of course leaving their bikini top
>lying by
>the pool... ;)

You must have been very young or very much in love :) - I'd call that
kind of behaviour a tad juvenile :O, but ofcourse that depends on the
behvioural pattern of the target models.... :)
If I tried that kind of stunts with the women I fancy, then I'd either
get slapped or at least quite surely not getting any further with that
particular lady :Q

--
Regards,

Helge

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