RE: How far can radio signals penetrate through ice?

2004-10-13 Thread Paul Lavin


Forgive me if I haven't been paying attention but it seems we need an
antenna on the surface and data collection down below.  The cable
connecting the two is likely to be a significant portion of the landed
mass if it is armoured in any way (which seems a good idea giving the
tectonic and abrasion unknowns).   And if it is posited that
there will be a breakthrough into a sub-ice liquid, then the probe will
be hanging on that thread.  It had better be beefy!
Why not consider a configuration that deploys an anchored antenna
array/transmitter while the main, cable-laden part of the lander 
melts its way down into the ice via bottom mounted radiators. 
Assuming the availability of a nuclear power source in the probe, you
could generate as much heat as you needed to make a penetrable slurry
bubble of reasonable size.  Fins on top would give it some steering
capability.  A lateral drill/sampler could extend to periodically
take uncooked samples.
Comms is maintained, great sonar and compositional data can be collected
on the way down and if there is a disconnect, we get all the data right
up until the Europans hacksaw the cable.
If there is some sensing capability in the cable itself, the transmitter
package left topside would at least be able to provide some further,
albeit greatly reduced, data.
We have off-the-shelf bathyscaph technology and marine cable technology
and would be fools to reinvent those wheels. 
My 2p's worth
Paul
At 09:10 13/10/2004, you wrote:
The
probe ought to be able to move and steer, as the possibility of
encountering way-blocking anisotropies in the ice is likely fairly
high.
 
The weak point in the return to
surface plan is the dead comm time.  Too expensive to not know
what's going on.
 
As for sonic transmission
ideas, one thing we might have a huge problem with is noise.  It may
well be that the Europan ice sphere is a profoundly noisy place due to
ice flexion and tectonic activity.  

Jack W. Reeve 
-Original Message-
From: Michael Turner
[mailto:[EMAIL PROTECTED]]

Sent: Wednesday 13 October 2004 13:17 
To: [EMAIL PROTECTED]
Subject: Re: How far can radio signals penetrate through
ice?
Good points, and I'd forgotten about the idea of a string of puck
transceivers.  They would probably be distributed so that if one
fails, the whole network doesn't go down.
 
OK, here's a really dumb idea: don't communicate.  Just
return to the surface with your data payload.
 
We're assuming something that can melt its way down. 
Why can't it also melt its way up?  Presumably it has an onboard
nuclear reactor, with a long MTBF.  If you evacuate a ballast tank
(filled with liquid water, which of course is denser than ice) and point
the thing up instead of down, it'll melt its way back up, right? 
That makes the whole thing bigger, because you need a large ballast tank,
but not much heavier as a delivered product, since that tank will mostly
be either empty volume or volume filled with either locally derived water
(on the way down) or water vapor (on the way up.)
 
Against this is the argument that you won't know what's
going on for long periods of time.  If something goes wrong with the
basic transport mechanism - melting through ice whether gravity-assisted
or buoyancy-assisted - you probably won't find out what the problem was,
short of visiting the failed probe using something like the same
technology that failed on you.  I guess if there's some backup
power, the acoustic transmission idea could work in a pinch (as it
were).  Low bit rates that would be unacceptable for large-scale
oceanography data dumps might still be tolerable for hardware
diagnosis.  (I know, because I've written diagnostics that talked
over some slow channels.)
 
One argument against this return-trip idea would seem to be
the massive lateral pressures.  How could water melted from the top,
on the return trip, make its way around the sides?  Well, you have
to solve this problem for going down as well.  I think if you just
let the melted water go through a channel inside the probe from the
leading head to the tail, it works for going up or down..
 
While you're at it, speed up the propulsion system by
generating steam behind the probe, regardless of which direction it's
going.  The ice will close up over the probe in short order on the
way down, so having a steam-filled cavity will push the probe like a
piston in a cylinder, with the probe boiling the water behind it. 
You already have to melt very cold ice (which will have roughly the same
specific heat as water), so going the extra mile and boiling the water as
well probably isn't going to cramp your energy budget much, and it may be
the faster way, compared to simply having a hotter heating element. This
would also work even better on the return trip, because coming back up
there will be no gravity-assist.  There's the bootstrap point where
it's initially melting

RE: How far can radio signals penetrate through ice?

2004-10-13 Thread Reeve, Jack W.
Title: Message



The 
probe ought to be able to move and steer, as the possibility of encountering 
way-blocking anisotropies in the ice is likely fairly high.
 
The 
weak point in the return to surface plan is the dead comm time.  Too 
expensive to not know what's going on.
 
As for 
sonic transmission ideas, one thing we might have a huge problem with is 
noise.  It may well be that the Europan ice sphere is a profoundly noisy 
place due to ice flexion and tectonic activity.  
Jack W. 
Reeve 

-Original Message-From: Michael Turner 
[mailto:[EMAIL PROTECTED] Sent: Wednesday 13 October 2004 13:17 
To: [EMAIL PROTECTED]Subject: Re: How far can radio signals 
penetrate through ice?
Good points, and I'd forgotten about the idea 
of a string of puck transceivers.  They would probably be distributed so 
that if one fails, the whole network doesn't go down.
 
OK, here's a really dumb idea: don't 
communicate.  Just return to the surface with your data 
payload.
 
We're assuming something that can melt its way 
down.  Why can't it also melt its way up?  Presumably it has an 
onboard nuclear reactor, with a long MTBF.  If you evacuate a ballast tank 
(filled with liquid water, which of course is denser than ice) and point the 
thing up instead of down, it'll melt its way back up, right?  That makes 
the whole thing bigger, because you need a large ballast tank, but not much 
heavier as a delivered product, since that tank will mostly be either empty 
volume or volume filled with either locally derived water (on the way down) 
or water vapor (on the way up.)
 
Against this is the argument that you won't 
know what's going on for long periods of time.  If something goes 
wrong with the basic transport mechanism - melting through ice whether 
gravity-assisted or buoyancy-assisted - you probably won't find out what the 
problem was, short of visiting the failed probe using something like the same 
technology that failed on you.  I guess if there's some backup power, the 
acoustic transmission idea could work in a pinch (as it were).  Low bit 
rates that would be unacceptable for large-scale oceanography data dumps might 
still be tolerable for hardware diagnosis.  (I know, because I've written 
diagnostics that talked over some slow channels.)
 
One argument against this return-trip idea 
would seem to be the massive lateral pressures.  How could water melted 
from the top, on the return trip, make its way around the 
sides?  Well, you have to solve this problem for going down as 
well.  I think if you just let the melted water go through a channel inside 
the probe from the leading head to the tail, it works for going up or 
down..
 
While you're at it, speed up the propulsion 
system by generating steam behind the probe, regardless of which direction it's 
going.  The ice will close up over the probe in short order on the way 
down, so having a steam-filled cavity will push the probe like a piston in a 
cylinder, with the probe boiling the water behind it.  You already have to 
melt very cold ice (which will have roughly the same specific heat as water), so 
going the extra mile and boiling the water as well probably isn't going to cramp 
your energy budget much, and it may be the faster way, compared to simply having 
a hotter heating element. This would also work even better on the return trip, 
because coming back up there will be no gravity-assist.  
There's the bootstrap point where it's initially melting upward while still 
suspended in water under the ice ceiling.  I suppose you could have a rear 
steam jet for that purpose.  Or a ballast tank that you'd need anyway for 
underwater maneuvers might provide enough buoyancy to get you 
started.
 
Here's an idea for EXTREMELY low-bit-rate 
communication in the meantime.  The probe can dissociate the hydrogen and 
oxygen in the frozen H2O it's melting through.  It can leave behind pockets 
of H2 and O2 gas, with a small disposable igniter or an igniter attached to a 
wire that that the probe drags behind it.  Or it can even just use space 
immediately behind it as the explosion cavity, with a reusable igniter built 
into the probe.  That way, even if it gets wedged, it still has a chance of 
communicating.  Ignition will cause an explosion/implosion.  And a 
powerful one: the H2/O2 mix will be very dense, just to compensate for the 
pressures down there.  Ignition could be triggered on a schedule given by 
an onboard clock, with a clock-tick granularity of, say, a few seconds, to 
compensate for any acoustic variability in the ice.  A probe on the surface 
hears an explosion, reads its own synchronized clock value, subtracts 
some frequently-adjusted value based speed-of-sound and current depth, and takes 
the low-order 8 bits of the result.  Voila: you've received a byte.  
By the nature of the arrangement, it'll be a while before you ca

Re: How far can radio signals penetrate through ice?

2004-10-12 Thread Michael Turner
- Original Message ----- 

  From: 
  Reeve, Jack W. 
  To: [EMAIL PROTECTED] 
  Sent: Wednesday, October 13, 2004 1:06 
  PM
  Subject: RE: How far can radio signals 
  penetrate through ice?
  
  We're re-inventing the wheel here.  Seems that 
  there was a plan wherein a series of puck-like transceivers could be left in 
  the ice upon descent, one every so many hundred or thousand meters.  Not 
  a bad idea, except for the dead batteries issue sooner or 
  later.
   
  Re 
  the cable.  no way it needs to be that big.  Assuming an optical 
  data line (0.75 mm), a primary conductor (2 mm, aluminum? - good weight vs. 
  conductivity ratio), and a heating element/shroud (0.5 mm thick, stainless or 
  titanium weave, each say 50 m electrically isolated, representing individual 
  elements), I can't see why the cable would have to be more than 3 - 4 mm 
  diameter = 07. - 1.26  line m3 @ 100 km.  Regularly heating the 
  cable would allow it to always seek its slackest situation in the ice, 
  eliminating tectonic shearing of the cable.  Element heating could be 
  cycled, or even activated based upon in-situ cable stress - reacting to 
  tectonics when required.  The cable would unspool from the probe upon 
  descent.
   
  In 
  truth, a 2nd signal could piggy-back on the primary conductor, so its got 
  built in redundancy.
   
  Sounds like off-the-shelf stuff to me.
  Jack W. 
  Reeve 
   -Original Message-----From: Sean McCutcheon 
  [mailto:[EMAIL PROTECTED] Sent: Wednesday 13 October 
  2004 02:39 To: [EMAIL PROTECTED]Subject: RE: How far can 
  radio signals penetrate through ice?
  
  Some good ideas being floated 
  around here... but if the lander 
  was prepared for the worst-case 
  depth of 100 km and the tether was only 2 cm thick (which probably would not be good enough without 
  exotic materials), that would be over 30 cubic meters of 
  cable. Sounds like a very heavy lander.
  Sean
   
  
-Original Message-From: [EMAIL PROTECTED] 
    [mailto:[EMAIL PROTECTED]On Behalf Of Gary 
    McMurtrySent: Tuesday, October 12, 2004 2:14 PMTo: 
[EMAIL PROTECTED]Subject: Re: How far can radio signals penetrate 
through ice?
Paul's humorous example was merely aimed at faulty processor speeds 
after the signals were transmitted, they got there at appropriately fast 
rates.  Seriously folks, we already have the capability to signal 
process out random noise, so not to worry.  Michael's point about power 
is a good one.  Whatever makes it as a lander on Europa will likely not 
be power limited in the sense that NASA probes are today.  BUT, it 
would have to be a pretty strong cable to hold up a fiber connection through 
all that ice, unless it was very stable, which it might not be.  The 
Loihi Seamount HUGO fiber cable lasted about 3 months.  It had some 
plastic and steel armor, but not enough.  It was about 1 inch in 
diameter.  See the SOEST web site for HUGO details: 
www.soest.hawaii.edu

Gary


Let's not conflate signals 
  and information with knowledge and wisdom, people.  It took 
  me two decades of ostensibly adult life before I developed the habit 
  (still observed more in the breach) of facing life's quandaries with the 
  question: "What would Dad do?"  My batting average went up to match 
  his level, modest as that has been.
 
Anyway, I go with an 
  acoustic solution, if it turns out to be impossible to cable a submarine 
  probe to surface communications.  Tap signals underneath, and listen 
  for them on top.  If you tap hard enough (and remember, we're talking 
  about a lot of power just to get through the ice, so power will be 
  available under the ice), the sound might be picked out out all the noise 
  from shifting, grinding ice.  The bit rate might be low, but 
  eventually the message would get out.
 
However, is there any reason 
  to think optical fiber couldn't be made strong enough to 
  withstand the crushing pressures, as the bore closed up behind the probe 
  melting its way through the ice?  Underwater acoustic communications 
  with a transceiver attached to that fiber on the underside of the ice 
  might keep the probe in contact with the surface.
 
-michael 
turner
[EMAIL PROTECTED]
      - Original Message -----
      From: Paul 
Lavin
  To: [EMAIL PROTECTED]
  Sent: Tuesday, October 12, 2004 11:35 PM
  Subject: RE: How far can radio signals penetrate 
through ice?
  
  A skeptic that is not an acute observer of life?  
(Europan or otherwise) ;-)Obviously Mickey has not yet tried to 
get an idea into a teenager's head...It takes years, believe 
me!  The transmission rate doesn't seem to increase appreciably 
with age in some subjects.PaulAt

RE: How far can radio signals penetrate through ice?

2004-10-12 Thread Reeve, Jack W.
Title: Message



We're 
re-inventing the wheel here.  Seems that there was a plan wherein a series 
of puck-like transceivers could be left in the ice upon descent, one every so 
many hundred or thousand meters.  Not a bad idea, except for the dead 
batteries issue sooner or later.
 
Re the 
cable.  no way it needs to be that big.  Assuming an optical data line 
(0.75 mm), a primary conductor (2 mm, aluminum? - good weight vs. conductivity 
ratio), and a heating element/shroud (0.5 mm thick, stainless or titanium weave, 
each say 50 m electrically isolated, representing individual elements), I can't 
see why the cable would have to be more than 3 - 4 mm diameter = 07. - 
1.26  line m3 @ 100 km.  Regularly heating the cable would allow it to 
always seek its slackest situation in the ice, eliminating tectonic shearing of 
the cable.  Element heating could be cycled, or even activated based upon 
in-situ cable stress - reacting to tectonics when required.  The cable 
would unspool from the probe upon descent.
 
In 
truth, a 2nd signal could piggy-back on the primary conductor, so its got built 
in redundancy.
 
Sounds 
like off-the-shelf stuff to me.
Jack W. 
Reeve 
 -Original Message-From: Sean McCutcheon 
[mailto:[EMAIL PROTECTED] Sent: Wednesday 13 October 2004 
02:39 To: [EMAIL PROTECTED]Subject: RE: How far can radio 
signals penetrate through ice?

Some good ideas being floated 
around here... but if the lander 
was prepared for the worst-case 
depth of 100 km and the tether was only 2 cm thick (which probably would not be good enough without 
exotic materials), that would be over 30 cubic meters of 
cable. Sounds like a very heavy lander.
Sean
 

  -Original Message-From: [EMAIL PROTECTED] 
  [mailto:[EMAIL PROTECTED]On Behalf Of Gary McMurtrySent: 
  Tuesday, October 12, 2004 2:14 PMTo: 
  [EMAIL PROTECTED]Subject: Re: How far can radio signals penetrate 
  through ice?
  Paul's humorous example was merely aimed at faulty processor speeds after 
  the signals were transmitted, they got there at appropriately fast 
  rates.  Seriously folks, we already have the capability to signal process 
  out random noise, so not to worry.  Michael's point about power is a good 
  one.  Whatever makes it as a lander on Europa will likely not be power 
  limited in the sense that NASA probes are today.  BUT, it would have to 
  be a pretty strong cable to hold up a fiber connection through all that ice, 
  unless it was very stable, which it might not be.  The Loihi Seamount 
  HUGO fiber cable lasted about 3 months.  It had some plastic and steel 
  armor, but not enough.  It was about 1 inch in diameter.  See the 
  SOEST web site for HUGO details: www.soest.hawaii.edu
  
  Gary
  
  
  Let's not conflate signals 
and information with knowledge and wisdom, people.  It took 
me two decades of ostensibly adult life before I developed the habit (still 
observed more in the breach) of facing life's quandaries with the question: 
"What would Dad do?"  My batting average went up to match his level, 
modest as that has been.
   
  Anyway, I go with an acoustic 
solution, if it turns out to be impossible to cable a submarine probe to 
surface communications.  Tap signals underneath, and listen for them on 
top.  If you tap hard enough (and remember, we're talking about a lot 
of power just to get through the ice, so power will be available under the 
ice), the sound might be picked out out all the noise from shifting, 
grinding ice.  The bit rate might be low, but eventually the message 
would get out.
   
  However, is there any reason 
to think optical fiber couldn't be made strong enough to withstand 
the crushing pressures, as the bore closed up behind the probe melting its 
way through the ice?  Underwater acoustic communications with a 
transceiver attached to that fiber on the underside of the ice might keep 
the probe in contact with the surface.
   
  -michael 
  turner
  [EMAIL PROTECTED]
- Original Message -
From: Paul 
  Lavin
To: [EMAIL PROTECTED]
Sent: Tuesday, October 12, 2004 11:35 PM
    Subject: RE: How far can radio signals penetrate 
  through ice?

A skeptic that is not an acute observer of life?  
  (Europan or otherwise) ;-)Obviously Mickey has not yet tried to 
  get an idea into a teenager's head...It takes years, believe 
  me!  The transmission rate doesn't seem to increase appreciably with 
  age in some subjects.PaulAt 15:27 12/10/2004, you 
  wrote:
  I am skeptic 
about the signal in bone rate. Sound travels through bone very rapidly 
akin to dense wood. Think of the hearing aids that send signals through 
the bone.  Diamond only slows light down 50% or 
so. Mickey -Original Message-From: [EMAIL PROTECTED] 
[mailto:[EMAIL PROTECTED] On B

RE: How far can radio signals penetrate through ice?

2004-10-12 Thread Sean McCutcheon
Title: Re: How far can radio signals penetrate through ice?




Some good ideas being floated 
around here... but if the lander 
was prepared for the worst-case 
depth of 100 km and the tether was only 2 cm thick (which probably would not be good enough without 
exotic materials), that would be over 30 cubic meters of 
cable. Sounds like a very heavy lander.
Sean
 

  -Original Message-From: [EMAIL PROTECTED] 
  [mailto:[EMAIL PROTECTED]On Behalf Of Gary McMurtrySent: 
  Tuesday, October 12, 2004 2:14 PMTo: 
  [EMAIL PROTECTED]Subject: Re: How far can radio signals penetrate 
  through ice?
  Paul's humorous example was merely aimed at faulty processor speeds after 
  the signals were transmitted, they got there at appropriately fast 
  rates.  Seriously folks, we already have the capability to signal process 
  out random noise, so not to worry.  Michael's point about power is a good 
  one.  Whatever makes it as a lander on Europa will likely not be power 
  limited in the sense that NASA probes are today.  BUT, it would have to 
  be a pretty strong cable to hold up a fiber connection through all that ice, 
  unless it was very stable, which it might not be.  The Loihi Seamount 
  HUGO fiber cable lasted about 3 months.  It had some plastic and steel 
  armor, but not enough.  It was about 1 inch in diameter.  See the 
  SOEST web site for HUGO details: www.soest.hawaii.edu
  
  Gary
  
  
  Let's not conflate signals 
and information with knowledge and wisdom, people.  It took 
me two decades of ostensibly adult life before I developed the habit (still 
observed more in the breach) of facing life's quandaries with the question: 
"What would Dad do?"  My batting average went up to match his level, 
modest as that has been.
   
  Anyway, I go with an acoustic 
solution, if it turns out to be impossible to cable a submarine probe to 
surface communications.  Tap signals underneath, and listen for them on 
top.  If you tap hard enough (and remember, we're talking about a lot 
of power just to get through the ice, so power will be available under the 
ice), the sound might be picked out out all the noise from shifting, 
grinding ice.  The bit rate might be low, but eventually the message 
would get out.
   
  However, is there any reason 
to think optical fiber couldn't be made strong enough to withstand 
the crushing pressures, as the bore closed up behind the probe melting its 
way through the ice?  Underwater acoustic communications with a 
transceiver attached to that fiber on the underside of the ice might keep 
the probe in contact with the surface.
   
  -michael 
  turner
  [EMAIL PROTECTED]
- Original Message -
From: Paul 
  Lavin
To: [EMAIL PROTECTED]
Sent: Tuesday, October 12, 2004 11:35 PM
    Subject: RE: How far can radio signals penetrate 
  through ice?

A skeptic that is not an acute observer of life?  
  (Europan or otherwise) ;-)Obviously Mickey has not yet tried to 
  get an idea into a teenager's head...It takes years, believe 
  me!  The transmission rate doesn't seem to increase appreciably with 
  age in some subjects.PaulAt 15:27 12/10/2004, you 
  wrote:
  I am skeptic 
about the signal in bone rate. Sound travels through bone very rapidly 
akin to dense wood. Think of the hearing aids that send signals through 
the bone.  Diamond only slows light down 50% or 
so. Mickey -Original Message-From: [EMAIL PROTECTED] 
[mailto:[EMAIL PROTECTED] On Behalf Of Paul 
LavinSent: Monday, October 11, 2004 3:11 AMTo: 
    [EMAIL PROTECTED]Subject: RE: How far can radio signals 
penetrate through ice? I'm not sure that the whales 
"communicate" over 100s of miles but their vocalisations can probably be 
heard that far away.Let's not forget that it takes some signals 
years to penetrate a quarter of an inch of bone... even at close 
range.;-)PaulAt 02:41 11/10/2004, you 
wrote:In the oil and gas business, seismic (sonar) 
description of rock formations is pretty accurate down to around 20,000 
feet, then starts to get a bit fuzzy. On earth, elephants 
use low frequency sound to communicate over 10's of miles, through 
air. In the oceans, many whale species utilize the lower 
frequencies of sound to communicate over vast distances, apparently in 
the 100's of miles, perhaps further. Best bet for sound 
answers (sorry), check with a whale person. Any whale 
people listening?  I'm typing at a really low frequency 
... Incidentally, I'm back in SE Asia, so I'll be sharing 
the same clock as Michael T for a few years.Jack W. Reeve-Original Message-From: LARRY KLAES 
[m

Re: How far can radio signals penetrate through ice?

2004-10-12 Thread Gary McMurtry
Title: Re: How far can radio signals penetrate through
ice?


Paul's humorous example was merely aimed at faulty processor
speeds after the signals were transmitted, they got there at
appropriately fast rates.  Seriously folks, we already have the
capability to signal process out random noise, so not to worry. 
Michael's point about power is a good one.  Whatever makes it as
a lander on Europa will likely not be power limited in the sense that
NASA probes are today.  BUT, it would have to be a pretty strong
cable to hold up a fiber connection through all that ice, unless it
was very stable, which it might not be.  The Loihi Seamount HUGO
fiber cable lasted about 3 months.  It had some plastic and steel
armor, but not enough.  It was about 1 inch in diameter. 
See the SOEST web site for HUGO details: www.soest.hawaii.edu

Gary


Let's not conflate
signals and information with knowledge and wisdom, people. 
It took me two decades of ostensibly adult life before I developed the
habit (still observed more in the breach) of facing life's quandaries
with the question: "What would Dad do?"  My batting
average went up to match his level, modest as that has
been.
 
Anyway, I go with an
acoustic solution, if it turns out to be impossible to cable a
submarine probe to surface communications.  Tap signals
underneath, and listen for them on top.  If you tap hard enough
(and remember, we're talking about a lot of power just to get through
the ice, so power will be available under the ice), the sound might be
picked out out all the noise from shifting, grinding ice.  The
bit rate might be low, but eventually the message would get
out.
 
However, is there any
reason to think optical fiber couldn't be made strong enough
to withstand the crushing pressures, as the bore closed up behind the
probe melting its way through the ice?  Underwater acoustic
communications with a transceiver attached to that fiber on the
underside of the ice might keep the probe in contact with the
surface.
 
-michael
turner
[EMAIL PROTECTED]
- Original Message -
From: Paul
Lavin
To: [EMAIL PROTECTED]
Sent: Tuesday, October 12, 2004 11:35
PM
Subject: RE: How far can radio signals penetrate
through ice?

A skeptic that is not an acute observer of life? 
(Europan or otherwise) ;-)

Obviously Mickey has not yet tried to get an idea into a teenager's
head...

It takes years, believe me!  The transmission rate doesn't seem
to increase appreciably with age in some subjects.

Paul

At 15:27 12/10/2004, you wrote:
I am
skeptic about the signal in bone rate. Sound travels through bone very
rapidly akin to dense wood. Think of the hearing aids that send
signals through the bone.  Diamond only slows light down 50% or
so.
 
Mickey
 
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Paul Lavin
Sent: Monday, October 11, 2004 3:11 AM
To: [EMAIL PROTECTED]
Subject: RE: How far can radio signals penetrate through
ice?
 
I'm not sure that the whales "communicate" over 100s of
miles but their vocalisations can probably be heard that far away.

Let's not forget that it takes some signals years to penetrate a
quarter of an inch of bone... even at close range.

;-)

Paul

At 02:41 11/10/2004, you wrote:


In the oil and gas business, seismic (sonar) description of rock
formations is pretty accurate down to around 20,000 feet, then starts
to get a bit fuzzy.
 
On earth, elephants use low frequency sound to communicate over 10's
of miles, through air.
 
In the oceans, many whale species utilize the lower frequencies of
sound to communicate over vast distances, apparently in the 100's of
miles, perhaps further.
 
Best bet for sound answers (sorry), check with a whale person.
 
Any whale people listening?  I'm typing at a really low frequency
...
 
Incidentally, I'm back in SE Asia, so I'll be sharing the same clock
as Michael T for a few years.

Jack W. Reeve
-Original Message-
From: LARRY KLAES [mailto:[EMAIL PROTECTED]
Sent: Saturday 09 October 2004
16:00
To: [EMAIL PROTECTED]
Subject: Re: How far can radio signals penetrate through
ice?

So maybe we can drop a large flat antenna on Icepick's landing
site on Europa first, one that can be folded up for the trip and
deployed when on the moon's surface.  No, I am not trying to be
funny.
 
But wait - how big will Icepick have to be to receive and send
data?
 
Larry
 
- Original Message -----
From: James McEnanly
To: [EMAIL PROTECTED]
Sent: Saturday, October 09, 2004 2:57 PM
Subject: Re: How far can radio signals penetrate through ice?
Usually it is by way of Extremely Low Frequencies. The antennae y=used
for this are often acres, if not square miles in size.
LARRY KLAES <[EMAIL PROTECTED]> wrote:
I know this may be under the Classified category, but have submarines
found ways to send signals through the ice packs when in the Arctic
Ocean?  I am just wonde

Re: How far can radio signals penetrate through ice?

2004-10-12 Thread Michael Turner



Let's not conflate signals 
and information with knowledge and wisdom, people.  It took me 
two decades of ostensibly adult life before I developed the habit (still 
observed more in the breach) of facing life's quandaries with the question: 
"What would Dad do?"  My batting average went up to match his level, modest 
as that has been.
 
Anyway, I go with an acoustic solution, if it 
turns out to be impossible to cable a submarine probe to surface 
communications.  Tap signals underneath, and listen for them on top.  
If you tap hard enough (and remember, we're talking about a lot of power just to 
get through the ice, so power will be available under the ice), the sound might 
be picked out out all the noise from shifting, grinding ice.  The bit rate 
might be low, but eventually the message would get out.
 
However, is there any reason to think 
optical fiber couldn't be made strong enough to withstand the crushing 
pressures, as the bore closed up behind the probe melting its way through the 
ice?  Underwater acoustic communications with a transceiver attached to 
that fiber on the underside of the ice might keep the probe in contact with the 
surface.
 
-michael turner
[EMAIL PROTECTED]

  - Original Message - 
  From: 
  Paul 
  Lavin 
  To: [EMAIL PROTECTED] 
  Sent: Tuesday, October 12, 2004 11:35 
  PM
  Subject: RE: How far can radio signals 
  penetrate through ice?
  A skeptic that is not an acute observer of life?  (Europan 
  or otherwise) ;-)Obviously Mickey has not yet tried to get an idea 
  into a teenager's head...It takes years, believe me!  The 
  transmission rate doesn't seem to increase appreciably with age in some 
  subjects.PaulAt 15:27 12/10/2004, you wrote:
  I am skeptic about the signal in bone rate. Sound travels through 
bone very rapidly akin to dense wood. Think of the hearing aids that send 
signals through the bone.  Diamond only slows light down 50% or 
so. Mickey  -Original Message-From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Paul 
LavinSent: Monday, October 11, 2004 3:11 AMTo: 
    [EMAIL PROTECTED]Subject: RE: How far can radio signals penetrate 
through ice? I'm not 
sure that the whales "communicate" over 100s of miles but their 
vocalisations can probably be heard that far away.Let's not forget 
that it takes some signals years to penetrate a quarter of an inch of 
bone... even at close range.;-)PaulAt 02:41 
11/10/2004, you wrote:In the oil and gas business, seismic 
(sonar) description of rock formations is pretty accurate down to around 
20,000 feet, then starts to get a bit fuzzy. On earth, 
elephants use low frequency sound to communicate over 10's of miles, through 
air. In the oceans, many whale species utilize the lower 
frequencies of sound to communicate over vast distances, apparently in the 
100's of miles, perhaps further. Best bet for sound answers 
(sorry), check with a whale person. Any whale people 
listening?  I'm typing at a really low frequency 
... Incidentally, I'm back in SE Asia, so I'll be sharing the 
same clock as Michael T for a few years.Jack W. Reeve -Original Message-From: LARRY KLAES [mailto:[EMAIL PROTECTED]] 
    Sent: Saturday 09 October 2004 16:00 To: 
    [EMAIL PROTECTED]Subject: Re: How far can radio signals penetrate 
through ice?So maybe we can drop a large flat antenna on 
Icepick's landing site on Europa first, one that can be folded up for the 
trip and deployed when on the moon's surface.  No, I am not trying to 
be funny. But wait - how big will Icepick have to be to receive 
and send data? Larry - Original Message - From: James McEnanly To: [EMAIL PROTECTED] Sent: Saturday, October 
09, 2004 2:57 PMSubject: Re: How far can radio signals penetrate through 
ice?Usually it is by way of Extremely Low Frequencies. The antennae 
y=used for this are often acres, if not square miles in size.LARRY KLAES 
<[EMAIL PROTECTED]> wrote: I know 
this may be under the Classified category, but have submarines found ways to 
send signals through the ice packs when in the Arctic Ocean?  I am just 
wondering if a similar technique could be used for Icepick so it doesn't 
have to drag a long cable after itself from the Europan 
surface. Thanks, Larry   Sincerely 
 James 
McEnanly__Do You 
Yahoo!?Tired of spam? Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com Paul LavinThe 
inventor of the phonograph thought he was inventing voicemail.Alexander 
Graham Bell was trying to invent muzak, not the telephone.  Whatis 
obvious now was far from obvious then.  What is obvious now is 
verylikely to be wrong in twenty years.+44 (0) 78 5541 1391 
mobile+4

RE: How far can radio signals penetrate through ice?

2004-10-12 Thread Paul Lavin


A skeptic that is not an acute observer of life?  (Europan or
otherwise)  ;-)
Obviously Mickey has not yet tried to get an idea into a teenager's
head...
It takes years, believe me!  The transmission rate doesn't seem to
increase appreciably with age in some subjects.
Paul
At 15:27 12/10/2004, you wrote:
I
am skeptic about the signal in bone rate. Sound travels through bone very
rapidly akin to dense wood. Think of the hearing aids that send signals
through the bone.  Diamond only slows light down 50% or so.
 
Mickey 
 
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]
On Behalf Of Paul Lavin
Sent: Monday, October 11, 2004 3:11 AM
To: [EMAIL PROTECTED]
Subject: RE: How far can radio signals penetrate through 
ice?
 
I'm not sure that the whales "communicate" over 100s of miles
but their vocalisations can probably be heard that far away.
Let's not forget that it takes some signals years to penetrate a quarter
of an inch of bone... even at close range.
;-)
Paul
At 02:41 11/10/2004, you wrote:

In the oil and gas business, seismic (sonar) description of rock
formations is pretty accurate down to around 20,000 feet, then starts to
get a bit fuzzy.
 
On earth, elephants use low frequency sound to communicate over 10's of
miles, through air.
 
In the oceans, many whale species utilize the lower frequencies of sound
to communicate over vast distances, apparently in the 100's of miles,
perhaps further.
 
Best bet for sound answers (sorry), check with a whale person.
 
Any whale people listening?  I'm typing at a really low frequency
...
 
Incidentally, I'm back in SE Asia, so I'll be sharing the same clock as
Michael T for a few years.
Jack W. Reeve

-Original Message-
From: LARRY KLAES
[mailto:[EMAIL PROTECTED]]

Sent: Saturday 09 October 2004 16:00 
To: [EMAIL PROTECTED]
Subject: Re: How far can radio signals penetrate through
ice?
So maybe we can drop a large flat antenna on Icepick's landing
site on Europa first, one that can be folded up for the trip and deployed
when on the moon's surface.  No, I am not trying to be funny.
 
But wait - how big will Icepick have to be to receive and send 
data?
 
Larry
 
- Original Message - 
From: James McEnanly 
To: [EMAIL PROTECTED] 
Sent: Saturday, October 09, 2004 2:57 PM
Subject: Re: How far can radio signals penetrate through ice?
Usually it is by way of Extremely Low Frequencies. The antennae y=used
for this are often acres, if not square miles in size.
LARRY KLAES <[EMAIL PROTECTED]> wrote:

I know this may be under the Classified category, but have submarines
found ways to send signals through the ice packs when in the Arctic
Ocean?  I am just wondering if a similar technique could be used for
Icepick so it doesn't have to drag a long cable after itself from the
Europan surface.
 
Thanks,
 
Larry
 
 
 
Sincerely 
 
James McEnanly
__
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around 
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Paul Lavin
The inventor of the phonograph thought he was inventing voicemail.
Alexander Graham Bell was trying to invent muzak, not the telephone.  What
is obvious now was far from obvious then.  What is obvious now is very
likely to be wrong in twenty years.

+44 (0) 78 5541 1391 mobile
+44 (0) 20 7291 0991 London office
+44 (0) 15 8246 2720 home office
+44 (0) 15 8246 2536 home fax 

Paul Lavin
The inventor of the phonograph thought he was inventing voicemail.
Alexander Graham Bell was trying to invent muzak, not the telephone.  What
is obvious now was far from obvious then.  What is obvious now is very
likely to be wrong in twenty years.

+44 (0) 78 5541 1391 mobile
+44 (0) 20 7291 0991 London office
+44 (0) 15 8246 2720 home office
+44 (0) 15 8246 2536 home fax 



RE: How far can radio signals penetrate through ice?

2004-10-12 Thread Schmidt Mickey D Civ HQ USAFA/DF








I am skeptic about the signal in bone
rate. Sound travels through bone very rapidly akin to dense wood. Think of the
hearing aids that send signals through the bone.  Diamond only slows light
down 50% or so.

 

Mickey 

 

-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Paul
Lavin
Sent: Monday, October 11, 2004
3:11 AM
To: [EMAIL PROTECTED]
Subject: RE: How far can radio
signals penetrate through ice?

 

I'm not sure that the whales "communicate"
over 100s of miles but their vocalisations can probably be heard that far away.

Let's not forget that it takes some signals years to penetrate a quarter of an
inch of bone... even at close range.

;-)

Paul

At 02:41 11/10/2004, you wrote:




In the oil and gas business, seismic (sonar)
description of rock formations is pretty accurate down to around 20,000 feet,
then starts to get a bit fuzzy.
 
On earth, elephants use low frequency sound to communicate over 10's of miles,
through air.
 
In the oceans, many whale species utilize the lower frequencies of sound to
communicate over vast distances, apparently in the 100's of miles, perhaps
further.
 
Best bet for sound answers (sorry), check with a whale person.
 
Any whale people listening?  I'm typing at a really low frequency ...
 
Incidentally, I'm back in SE Asia, so I'll be sharing the same clock as Michael
T for a few years.

Jack W. Reeve 
-Original Message-
From: LARRY KLAES [mailto:[EMAIL PROTECTED]] 
Sent: Saturday 09 October 2004
16:00 
To: [EMAIL PROTECTED]
Subject: Re: How far can radio
signals penetrate through ice?

So maybe we can drop a large flat antenna on Icepick's landing
site on Europa first, one that can be folded up for the trip and deployed when
on the moon's surface.  No, I am not trying to be funny.
 
But wait - how big will Icepick have to be to receive and send data?
 
Larry
 

- Original Message - 

From: James
McEnanly 

To: [EMAIL PROTECTED]


Sent: Saturday, October 09, 2004 2:57 PM

Subject:
Re: How far can radio signals penetrate through ice?

Usually
it is by way of Extremely Low Frequencies. The antennae y=used for this are
often acres, if not square miles in size.

LARRY KLAES <[EMAIL PROTECTED]>
wrote: 

I know this may be under the Classified category, but
have submarines found ways to send signals through the ice packs when in the
Arctic Ocean?  I am just wondering if a similar technique could be used
for Icepick so it doesn't have to drag a long cable after itself from the
Europan surface.

 

Thanks,

 

Larry

 

 

 

Sincerely


 

James
McEnanly

__

Do You Yahoo!?

Tired of spam? Yahoo! Mail has the best spam
protection around 

http://mail.yahoo.com


Paul Lavin

The inventor of the phonograph thought he was inventing voicemail.
Alexander Graham Bell was trying to invent muzak, not the telephone.  What
is obvious now was far from obvious then.  What is obvious now is very
likely to be wrong in twenty years.


+44 (0) 78 5541 1391 mobile
+44 (0) 20 7291 0991 London office
+44 (0) 15 8246 2720 home office
+44 (0) 15 8246 2536 home fax 








RE: How far can radio signals penetrate through ice?

2004-10-11 Thread Paul Lavin


I'm not sure that the whales "communicate" over 100s of miles
but their vocalisations can probably be heard that far away.
Let's not forget that it takes some signals years to penetrate a quarter
of an inch of bone... even at close range.
;-)
Paul
At 02:41 11/10/2004, you wrote:
In the oil and gas business,
seismic (sonar) description of rock formations is pretty accurate down to
around 20,000 feet, then starts to get a bit fuzzy.
 
On earth, elephants use low frequency sound to communicate over 10's of
miles, through air.
 
In the oceans, many whale species utilize the lower frequencies of sound
to communicate over vast distances, apparently in the 100's of miles,
perhaps further.
 
Best bet for sound answers (sorry), check with a whale person.
 
Any whale people listening?  I'm typing at a really low frequency
...
 
Incidentally, I'm back in SE Asia, so I'll be sharing the same clock as
Michael T for a few years.
Jack W. Reeve
  
-Original Message-
From: LARRY KLAES [mailto:[EMAIL PROTECTED]] 
Sent: Saturday 09 October 2004 16:00 
To: [EMAIL PROTECTED]
Subject: Re: How far can radio signals penetrate through ice?
So maybe we can drop a large flat antenna on Icepick's landing site on Europa first, one that can be folded up for the trip and deployed when on the moon's surface.  No, I am not trying to be funny.
 
But wait - how big will Icepick have to be to receive and send data?
 
Larry
 


- Original Message - 

From: James McEnanly 

To: [EMAIL PROTECTED] 

Sent: Saturday, October 09, 2004 2:57 PM

Subject: Re: How far can radio signals penetrate through ice?

Usually it is by way of Extremely Low Frequencies. The antennae y=used for this are often acres, if not square miles in size.

LARRY KLAES <[EMAIL PROTECTED]> wrote: 


I know this may be under the Classified category, but have submarines found ways to send signals through the ice packs when in the Arctic Ocean?  I am just wondering if a similar technique could be used for Icepick so it doesn't have to drag a long cable after itself from the Europan surface.

 

Thanks,

 

Larry

 

 



Sincerely 

 

James McEnanly

__

Do You Yahoo!?

Tired of spam? Yahoo! Mail has the best spam protection around 

http://mail.yahoo.com 



Paul Lavin
The inventor of the phonograph thought he was inventing voicemail.
Alexander Graham Bell was trying to invent muzak, not the telephone.  What
is obvious now was far from obvious then.  What is obvious now is very
likely to be wrong in twenty years.

+44 (0) 78 5541 1391 mobile
+44 (0) 20 7291 0991 London office
+44 (0) 15 8246 2720 home office
+44 (0) 15 8246 2536 home fax 



RE: How far can radio signals penetrate through ice?

2004-10-10 Thread Reeve, Jack W.
Title: Message



In the oil and gas business, seismic (sonar) 
description of rock formations is pretty accurate down to around 20,000 feet, 
then starts to get a bit fuzzy.
 
On earth, elephants use low frequency sound 
to communicate over 10's of miles, through air.
 
In the oceans, many whale species utilize 
the lower frequencies of sound to communicate over vast distances, apparently in 
the 100's of miles, perhaps further.
 
Best bet for sound answers (sorry), check 
with a whale person.
 
Any whale people listening?  I'm typing 
at a really low frequency ...
 
Incidentally, I'm back in SE Asia, so I'll 
be sharing the same clock as Michael T for a few years.
Jack W. 
Reeve   

-Original Message-From: LARRY KLAES 
[mailto:[EMAIL PROTECTED] Sent: Saturday 09 October 2004 16:00 
To: [EMAIL PROTECTED]Subject: Re: How far can radio signals 
penetrate through ice?

So maybe we can drop a large flat antenna on Icepick's landing site on 
Europa first, one that can be folded up for the trip and deployed when on the 
moon's surface.  No, I am not trying to be funny.
 
But wait - how big will Icepick have to be to receive and send data?
 
Larry
 

  - Original Message - 
  From: James McEnanly 
  To: [EMAIL PROTECTED] 
  Sent: Saturday, October 09, 2004 2:57 
  PM
  Subject: Re: How far can radio signals 
  penetrate through ice?
  
  Usually it is by way of Extremely Low Frequencies. The antennae y=used 
  for this are often acres, if not square miles in size.LARRY 
  KLAES <[EMAIL PROTECTED]> wrote: 
  



I know this may be under the Classified category, but have submarines 
found ways to send signals through the ice packs when in the Arctic 
Ocean?  I am just wondering if a similar technique could be used for 
Icepick so it doesn't have to drag a long cable after itself from the 
Europan surface.
 
Thanks,
 
Larry
 
 
  Sincerely 
   
  James McEnanly
  __Do You 
  Yahoo!?Tired of spam? Yahoo! Mail has the best spam protection around 
  http://mail.yahoo.com 


Re: How far can radio signals penetrate through ice?

2004-10-09 Thread LARRY KLAES




So maybe we can drop a large flat antenna on Icepick's landing site on 
Europa first, one that can be folded up for the trip and deployed when on the 
moon's surface.  No, I am not trying to be funny.
 
But wait - how big will Icepick have to be to receive and send data?
 
Larry
 

  - Original Message - 
  From: James McEnanly 
  To: [EMAIL PROTECTED] 
  Sent: Saturday, October 09, 2004 2:57 
  PM
  Subject: Re: How far can radio signals 
  penetrate through ice?
  
  Usually it is by way of Extremely Low Frequencies. The antennae y=used 
  for this are often acres, if not square miles in size.LARRY 
  KLAES <[EMAIL PROTECTED]> wrote: 
  



I know this may be under the Classified category, but have submarines 
found ways to send signals through the ice packs when in the Arctic 
Ocean?  I am just wondering if a similar technique could be used for 
Icepick so it doesn't have to drag a long cable after itself from the 
Europan surface.
 
Thanks,
 
Larry
 
 
  Sincerely 
   
  James McEnanly
  __Do You 
  Yahoo!?Tired of spam? Yahoo! Mail has the best spam protection around 
  http://mail.yahoo.com 


Re: How far can radio signals penetrate through ice?

2004-10-09 Thread James McEnanly
Usually it is by way of Extremely Low Frequencies. The antennae y=used for this are often acres, if not square miles in size.LARRY KLAES <[EMAIL PROTECTED]> wrote:




I know this may be under the Classified category, but have submarines found ways to send signals through the ice packs when in the Arctic Ocean?  I am just wondering if a similar technique could be used for Icepick so it doesn't have to drag a long cable after itself from the Europan surface.
 
Thanks,
 
Larry
 
 Sincerely 
 
James McEnanly__Do You Yahoo!?Tired of spam?  Yahoo! Mail has the best spam protection around http://mail.yahoo.com 

Re: How far can radio signals penetrate through ice?

2004-10-09 Thread Michael Turner



If radar worked through ice, it would probably work 
through water.  Submarines echolocate by sonar, rather than radar.  
That should tell you something.  (This, by the way, may be a flaw in 
Deception Point.  I'd been assuming that the meteorite buried deep in 
Arctic ice in that novel was detected by gravitometry, but the novel has radar 
as the detection medium. Hm, iffy.  But what do you expect of a novel 
predicated on this: that NASA scientists had to download and analyze BY HAND the 
radar data that they expected would be analyzed in the satellite using uploaded 
software that turned out to be buggy.  Har!  As if there were analysis 
software that could only run in a satellite.  And this is not to speak of 
the Roadrunner Physics in the action sequences.  Why, I could write a book 
... )
 
Maybe some kind of submarine clapper could send sound 
signals through the ice, but if that ice is as deep as suspected, and constantly 
shifting, it might be a major exercise in signal filtering, and require a lot of 
energy.  The energy requirement is already a problem that has to be solved, 
however.  Melting/boring through that ice is probably going to require an 
onboard nuclear reactor.
 
There's been talk of neutrino communications - not 
just underwater, but through the earth - but nothing like anything that could be 
practical as far as I know.  You need gigantic receiver arrays, and the 
transmission rates would be pathetic.
 
-michael

  - Original Message - 
  From: 
  LARRY KLAES 
  To: europa 
  Sent: Sunday, October 10, 2004 12:46 
  AM
  Subject: How far can radio signals 
  penetrate through ice?
  
  I know this may be under the Classified category, but have submarines 
  found ways to send signals through the ice packs when in the Arctic 
  Ocean?  I am just wondering if a similar technique could be used for 
  Icepick so it doesn't have to drag a long cable after itself from the Europan 
  surface.
   
  Thanks,
   
  Larry
   
   


How far can radio signals penetrate through ice?

2004-10-09 Thread LARRY KLAES



I know this may be under the Classified category, but have submarines found 
ways to send signals through the ice packs when in the Arctic Ocean?  I am 
just wondering if a similar technique could be used for Icepick so it doesn't 
have to drag a long cable after itself from the Europan surface.
 
Thanks,
 
Larry