What time is it at the North Pole?
Edward Zotti
Pole--and South Pole for that matter? All the time zones come to a point at
these locations. I suspect GMT, but would like to hear (ideally) from someone
who's been there, or knows who the definitive source would be on this. Doing
research for a newspaper column. Replies by e-mail appreciated. -Ed
PS: what time do the astronauts use while in orbit--GMT? Houston?
Pat
The other question, is which waay is south at the north pole?
but for space missions, i think they use Mission Elapsed time.
they aren't synced to any time zone. why bother, their day
is only 90 minutes long, and for apollo missions, i don't think they had a
day.
pat
--
-----------------------------------------------------------------------------
No matter how dire the situation, don't panic -- LLIB #280
richard graham
>Not the most profound question in the world, but what time is it at the North
>Pole--and South Pole for that matter? All the time zones come to a point at
>these locations. I suspect GMT, but would like to hear (ideally) from someone
>who's been there, or knows who the definitive source would be on this. Doing
>research for a newspaper column. Replies by e-mail appreciated. -Ed
McMurdo, the main U.S. base (small frontier town actually) is on New Zealand
standard time, as is South Pole Station. The reason being that flights to
and from the Antarctic orginate from there. Scott Base ~4 km from McMurdo is
likewise on New Zealand Standard Time as are all the other bases (that I know
of in the Ross Sea region). Field parties are expected to answer daily 'comms'
at 7:30am; beyond this day/night is mostly illrelevent. Most parties stay on
this schedule out of convience. However, if one is a geologist working on the
south facing slope of a valley, one might invert this schedule so as to work
in the sun. Day vs. night temps in 24 hr sunlight are not too far different;
however, sunlight vs shade temps can be *vastly* different. For example, one
season I worked in the Dominion Range (Beardmore Glacier Region) we stayed
on on McMurdo time the entire season--including a 3 day trip to The Cluodmaker
(north side of Beardmore Gl). Had we spent more than 3 days there I'm certain
we would have inverted our schedule.
Seasonal stations: Byrd Surface, CASERTZ or Dome C often work 'round the clock.
This is particularly true if the work concerns ice core drilling or air-bourne
geophysics. GPS satellites can cause another constraint. Given the
incomplete compliment of satellites, windows exist in which the minimum number
of satellites are in view to get the desired accuracy (as I recall sub-meter
accuracy requires 4 satellites to be in view). This condition bears little in
relation to GMT or any other time for that matter.
The other year-round US station--Palmer Station (on the Antarctic Pensula)--I
think stays on the same time as McMurdo and South Pole.
I would suspect the other countries would follow suite...that is to say their
stations would be on the time of the location of their logistic center. So
Casey Station (Australia) would be on Sydney (or Melbourne) time (?).
Richard Graham OAE
Henry Spencer
>... Most parties stay on this
>schedule out of convience. However, if one is a geologist working on the
>south facing slope of a valley, one might invert this schedule so as to work
Another example: Amundsen inverted his schedule on leaving the South Pole,
so that he'd have the Sun behind him, rather than in his eyes, during the
"day" on the return trip.
--
Belief is no substitute | Henry Spencer @ U of Toronto Zoology
for arithmetic. | he...@zoo.toronto.edu utzoo!henry
Christina Hulbe
>
>>Not the most profound question in the world, but what time is it at the North
>>Pole--and South Pole for that matter? All the time zones come to a point at
>
>McMurdo, the main U.S. base (small frontier town actually) is on New Zealand
I like to think of it as a western (U.S.) mining town
>standard time, as is South Pole Station. The reason being that flights to
>and from the Antarctic orginate from there. Scott Base ~4 km from McMurdo is
>likewise on New Zealand Standard Time as are all the other bases (that I know
>of in the Ross Sea region). Field parties are expected to answer daily 'comms
[more stuff deleted]
>Seasonal stations: Byrd Surface, CASERTZ or Dome C often work 'round the clock
hey, you left out the *most* important camp in the region, UPB, on Ice Stream
B! (which this year moved south a cople of km && is called OUTB). My
field team's main work is surveying with GPS, which uses GMT, so that's
the time we adopt, it is simply shifted 12 hours. That was fine in 91/92,
when McMurdo used NZ standard time but in 92/93, they decided to use
NZ daylight time so they differed from GMT by 13, rather than 12, hours.
(at least I think it was 13, maybe 11)
We stuck with the 12 hour shift, && had our own time zone out there.
We put an extra hour hand on the clock, one for UpB && one for McMurdo,
so we wouldn't miss comms.
>This is particularly true if the work concerns ice core drilling or air-bourne
>geophysics. GPS satellites can cause another constraint. Given the
>incomplete compliment of satellites, windows exist in which the minimum number
actually, it is a full compliment now. A problem with Antarctica though
is that GPS satellites never go directly over-head. Of course, even
with a large # of satellites, the geometry can still be poor.
>of satellites are in view to get the desired accuracy (as I recall sub-meter
>accuracy requires 4 satellites to be in view). This condition bears little i
>relation to GMT or any other time for that matter.
[stuff deleted]
>
>Richard Graham OAE
>
Christina Hulbe, YAE
richard graham
>In article <2ei98e$5...@crcnis1.unl.edu> rgr...@unlinfo.unl.edu (richard graham
>) writes:
>>ezo...@merle.acns.nwu.edu (Edward Zotti) writes:
>>
>>McMurdo, the main U.S. base (small frontier town actually) is on New Zealand
>I like to think of it as a western (U.S.) mining town
I was trying to be a bit more PC ;)....I'd originally written 'South Pole (that
geopolitical statement) but had deleted it out of my post.
>>Seasonal stations: Byrd Surface, CASERTZ or Dome C often work 'round the clock
>hey, you left out the *most* important camp in the region, UPB, on Ice Stream
...I wasn't trying to slight you....It's just that I heard UPB had been
swollowed by 'The Snake'... :]. Oh well, I gues the rumour of it's demise
had been greatly exaggerated. Shouldn't take long, with surface velocities
approaching a klick per year, though ;).
>NZ daylight time so they differed from GMT by 13, rather than 12, hours.
>(at least I think it was 13, maybe 11)
If it's today here and tommarow there when was it yesterday?
>>Richard Graham OAE
Yeah I guess YAE is what I am too....I'm only 30.
>Christina Hulbe, YAE
Frank Crary
>but for space missions, i think they use Mission Elapsed time.
>they aren't synced to any time zone. why bother, their day
>is only 90 minutes long, and for apollo missions, i don't think they had a
>day.
It depends on the mission. Manned missions use Central time, since the
people at mission control in Huston are on it. For deep space missions,
Elapsed time is often inconvienient (who wants to write all four
digits of a Voyager elapsed time, e.g. Day 2307...) It's more
common to see SET, Spacecraft Event Time, set to zero at some
important event in the mission. That keeps the numbers fairly
small and easy to remember. So for example the Voyager flyby of Io was
(if memory serves) 1430 of Day 14, SET.
Frank Crary
CU Boulder
Michael Moroney
>It depends on the mission. Manned missions use Central time, since the
>people at mission control in Huston are on it. For deep space missions,
Why then did the Hubble repair mission astronauts seem to start their
workdays about 10PM Eastern time and work through the night?
-Mike
Josh Hopkins
>fcr...@ucsu.Colorado.EDU (Frank Crary) writes:
Because of the launch window to rendezvous with Hubble, Endeavour had to
launch very early in the morning (and the astronauts had to be up well before
that). In cases like this, NASA prefers not to confuse the astronaut's
internal clock more than necessary. Once the astronauts shifted their
schedules for launch, they kept them that way.
--
Josh Hopkins jbh5...@uxa.cso.uiuc.edu
"Things get worse under pressure"
- Murphy's Law of Thermodynamics
danny burstein
in teh book, "Nautilus 90 degrees North", written by teh commander of teh
first ship (or are submarines boats?) to make it to teh North Pole,
Greenwich Mean Time is used throughout.
(The title refers to the navigation/location signal they sent when getting
there. With one other exception, every location on the Earth requires two
data points, latitude and longitude.
two brownie points to the first person who guesses the other one)
--
----------------------------------
dan...@panix.com adds: all the usual disclaimers regarding liability,
intelligence, accuracy apply. spelling disclaimer is doubled.
David Tholen
>> Not the most profound question in the world, but what time is it at the North
>> Pole--and South Pole for that matter? All the time zones come to a point at
>> these locations. I suspect GMT, but would like to hear (ideally) from someone
>> who's been there, or knows who the definitive source would be on this. Doing
>> research for a newspaper column. Replies by e-mail appreciated. -Ed
> in teh book, "Nautilus 90 degrees North", written by teh commander of teh
> first ship (or are submarines boats?) to make it to teh North Pole,
> Greenwich Mean Time is used throughout.
This reminds me of a recent colloquium during which the speaker, who was
talking about some research project at Antarctica, mentioned with a straight
face that the winds are very consistent at the South Pole: they're always
out of the north! After a round of laughter from the audience, he had to
explain that the convention at the South Pole is that the Greenwich
meridian represents north for them.
Robert Casey
>
>in the book, "Nautilus 90 degrees North", written by the commander of teh
>first ship (or are submarines boats?) to make it to the North Pole,
>Greenwich Mean Time is used throughout.
>
>(The title refers to the navigation/location signal they sent when getting
>there. With one other exception, every location on the Earth requires two
>data points, latitude and longitude.
> two brownie points to the first person who guesses the other one)
>
David Halliwell
>in teh book, "Nautilus 90 degrees North", written by teh commander of teh
>first ship (or are submarines boats?) to make it to teh North Pole,
>Greenwich Mean Time is used throughout.
The way I heard it, it's a boat if you can put it on a ship....
>(The title refers to the navigation/location signal they sent when getting
>there. With one other exception, every location on the Earth requires two
>data points, latitude and longitude.
> two brownie points to the first person who guesses the other one)
With an additional two brownie points for pointing out that we would
never expect to get a radio message sent from that location by someone in
a submarine....
...and since I have yet to see an actual answer to the question in the
subject heading...
I belive that the international agreements establishing concepts of
standard time and time zones stipulate that the polar regions do not have
any legal time. People are free to do whatever they wish!
--
Dave Halliwell
Department of Geography
University of Alberta
Edmonton, Alberta
John Hutton Cooper
richard graham <rgr...@unlinfo.unl.edu> wrote:
>chu...@magnus.acs.ohio-state.edu (Christina Hulbe) writes:
>I was trying to be a bit more PC ;)....I'd originally written
'South Pole (that
>geopolitical statement) but had deleted it out of my post.
I don't think the term "South Pole" is politically incorrect . . . .
it's electromagnetically incorrect (the South geographically is the
North magnetic pole of the Earth), but I don't think South pole
suggests Northern centricism - it's not as if we call the North Pole
"The Near Pole" and the South Pole "The Distant Pole." Not like
the term "Down Under." Is it true that Australians call the US
"Yankee Land"? Those British-centric Australians!
--
My own opinions, etc. John Hutton Cooper
jhco...@ocf.Berkeley.EDU
Greg Stewart-Nicholls
>Is it true that Australians call the US
>"Yankee Land"? Those British-centric Australians!
America :-)
-----------------------------------------------------------------
Greg Nicholls ... : Vidi
ni...@vnet.ibm.com or : Vici
ni...@olympus.demon.co.uk : Veni
Christina Hulbe
Christina Hulbe
chu...@magnus.acs.ohio-state.edu
Byrd Polar Research Center, *Some* Ohio State University
Henry Spencer
>>(The title refers to the navigation/location signal they sent when getting
>
> With an additional two brownie points for pointing out that we would
>never expect to get a radio message sent from that location by someone in
>a submarine....
Sorry, only one brownie point for you, David. Submarines can and do surface
in the vicinity of the Pole. In summer, ice-free patches of surface
occur with some frequency. In summer or winter, a suitably-designed
submarine can surface through thin ice. US subs do this sort of thing
now and then.
David does get one brownie point because the Nautilus did not do any of
this. It was the USS Skate, a year or two later, that ran the first tests
of surfacing in the icecap region, including at the Pole.
Andrew L. Alden
-"This reminds me of a recent colloquium during which the speaker, who was
-"talking about some research project at Antarctica, mentioned with a straight
-"face that the winds are very consistent at the South Pole: they're always
-"out of the north! After a round of laughter from the audience, he had to
-"explain that the convention at the South Pole is that the Greenwich
-"meridian represents north for them.
That convention also explains how to tell East Antarctica from West
Antarctica.
--
Andrew L. Alden | Backward I see in my own days where I sweated
al...@netcom.com | through fog with linguists and contenders...
al...@well.sf.ca.us | --Walt Whitman, years before Usenet
Matthew R. Feulner
|> In article <2eishc$9...@crcnis1.unl.edu>,
|> richard graham <rgr...@unlinfo.unl.edu> wrote:
|> >chu...@magnus.acs.ohio-state.edu (Christina Hulbe) writes:
|> >I was trying to be a bit more PC ;)....I'd originally written
|> 'South Pole (that
|> >geopolitical statement) but had deleted it out of my post.
|>
|> I don't think the term "South Pole" is politically incorrect . . . .
|> it's electromagnetically incorrect
No it isn't, the north pole of a compass magnet points North. :-)
Matthew Feulner All comments are strictly my own.
mfeu...@draper.com
Gary Coffman
>
>Sorry, only one brownie point for you, David. Submarines can and do surface
>in the vicinity of the Pole. In summer, ice-free patches of surface
>occur with some frequency. In summer or winter, a suitably-designed
>submarine can surface through thin ice. US subs do this sort of thing
>now and then.
Oh dear, this is an off day for you Henry. In the part you cut, he's
refering to the *other* pole. I don't think any US subs have surfaced
at the *South Pole*.
Gary
--
Gary Coffman KE4ZV | I kill you, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | You kill me, | uunet!rsiatl!ke4zv!gary
534 Shannon Way | We're the Manson Family | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244 | -sorry Barney |
Stan Bischof
: Oh dear, this is an off day for you Henry. In the part you cut, he's
: refering to the *other* pole. I don't think any US subs have surfaced
: at the *South Pole*.
Would be a good trick, since there is solid rock below the South Pole
(unlike the North Pole, which is indeed a floating mass of ice)
--
Stan Bischof
HPSR
DaveHatunen
>>>(The title refers to the navigation/location signal they sent when getting
>>>there...
>>
>> With an additional two brownie points for pointing out that we would
>>never expect to get a radio message sent from that location by someone in
>>a submarine....
>
>Sorry, only one brownie point for you, David. Submarines can and do surface
>in the vicinity of the Pole. In summer, ice-free patches of surface
>occur with some frequency. In summer or winter, a suitably-designed
>submarine can surface through thin ice. US subs do this sort of thing
>now and then.
Um. I think the reference was to the South Pole. I haven't heard of any
subs making it all the way.
--
********** DAVE HATUNEN (hat...@netcom.com) **********
* Daly City California: *
* where San Francisco meets The Peninsula *
* and the San Andreas Fault meets the Sea *
*******************************************************
Cleo Coles
JH> it's electromagnetically incorrect (the South geographically is the
JH> North magnetic pole of the Earth), but I don't think South pole
JH> suggests Northern centricism - it's not as if we call the North Pole
JH> "The Near Pole" and the South Pole "The Distant Pole." Not like
JH> the term "Down Under." Is it true that Australians call the US
JH> "Yankee Land"? Those British-centric Australians!
JH> --
JH> My own opinions, etc. John Hutton Cooper
Is the a joke? Is the dreaded PC disease spreading even to here?
Please, say it isn't so!
---
* MikeMayl v1.0 * TOE: Device for finding furniture in the dark...
David Halliwell
>In article <CI36q...@zoo.toronto.edu> he...@zoo.toronto.edu (Henry Spencer) writes:
>>
>>Sorry, only one brownie point for you, David. Submarines can and do surface
>>in the vicinity of the Pole. In summer, ice-free patches of surface
>>occur with some frequency. In summer or winter, a suitably-designed
>>submarine can surface through thin ice. US subs do this sort of thing
>>now and then.
>Oh dear, this is an off day for you Henry. In the part you cut, he's
>refering to the *other* pole. I don't think any US subs have surfaced
>at the *South Pole*.
It does appear that I was being a bit too subtle. I was indeed
referring to the other pole, implying that I knew the answer to the
original puzzle and could provide a hint to those that had not yet figured
it out!
Charles Allen
Buzz - Wrong!
Opposite poles of magnets attract.
Since the north pole of a magnet is attracted to the north direction
on the earth, it is by definition attracted to the south magnetic
pole of the earth. The south magnetic pole of the earth is in the
north, and the north magnetic pole of the earh is in the south.
Charles A.
cba...@hubcap.clemson.edu
Matthew R. Feulner
|> mrf...@egbsun18.NoSubdomain.NoDomain (Matthew R. Feulner) writes:
|>
|> >In article <2emeun$8...@agate.berkeley.edu>, jhco...@uclink.berkeley.edu (John Hutton Cooper) writes:
|> >|> In article <2eishc$9...@crcnis1.unl.edu>,
|> >|> richard graham <rgr...@unlinfo.unl.edu> wrote:
|> >|> >chu...@magnus.acs.ohio-state.edu (Christina Hulbe) writes:
|> >|> >I was trying to be a bit more PC ;)....I'd originally written
|> >|> 'South Pole (that
|> >|> >geopolitical statement) but had deleted it out of my post.
|> >|>
|> >|> I don't think the term "South Pole" is politically incorrect . . . .
|> >|> it's electromagnetically incorrect
|>
|> >No it isn't, the north pole of a compass magnet points North. :-)
|>
|> >Matthew Feulner All comments are strictly my own.
|> >mfeu...@draper.com
|>
|> Buzz - Wrong!
|> Opposite poles of magnets attract.
|> Since the north pole of a magnet is attracted to the north direction
|> on the earth, it is by definition attracted to the south magnetic
|> pole of the earth. The south magnetic pole of the earth is in the
|> north, and the north magnetic pole of the earh is in the south.
|>
|> Charles A.
|> cba...@hubcap.clemson.edu
Ok, Chuck, you tell me what the difference is between my version and yours.
Keep in mind that the word "North" ("N" is capitalized) means "in the north
direction on the earth." Also note the smiley which means that it was a joke.
It's called a play on words.
Bing Bing Bing - Right!
I'll take the trip for two to Hawaii for $1200, the ceramic pig for $200, and
the rest on account, please.
Andrew L. Alden
-"... I don't think any US subs have surfaced
-"at the *South Pole*.
A sub of an unknown nation surfaced there over a hundred years ago, as
documented in _20,000 Leagues Under the Sea_.
Charles Allen
Somewhere back in this bizzare discussion someone said that the
south pole is electromagnetically incorrect, which you disputed.
You were wrong. If you view earth as a magnet, the north magnetic
pole is near the south geographic pole (at the present time). That's
why the south pole
of your compass is attracted to it.
I'll take the bonus trip to Antarctica to verify my postulations... :-)
Now, Let's see how many people know anything about this:
How many times do we know of the earth swapping it's magnetic field?
How frequently does it happen? why? how? etc...
What would happen to us if it occurred tomorrow (technologically
speaking). Do we still depend on the magnetic field of the earth for
anything like navigation, or has the GPS satellites taken over?
- Charles A.
cba...@hubcap.clemson.edu
Rick Mollenkopf
Greetings from Bakersfield CA.,
You have piqued my curiosity. Where did the apparently arbitrary
conventions of North and South or even East and West come from?
I always believed the concept of geographic North predated that
of magnetic North. Perhaps when this is answered it will be TIME
to seek a new topic regardless of one's geographic position.
Rick "Got-a dime?" Mollenkopf
Henry Spencer
>How many times do we know of the earth swapping it's magnetic field?
>What would happen to us if it occurred tomorrow (technologically
>speaking). Do we still depend on the magnetic field of the earth for
>anything like navigation, or has the GPS satellites taken over?
Having the poles swap would be a *massive* inconvenience. Magnetic
compasses are still in very wide use, especially in low-tech applications
like ocean navigation. (Ordinary GPS receivers, incidentally, will tell
you position but *not* direction, so you still need a compass of some
type.) It wouldn't be just a case of cranking in a 180-degree bias,
because the transition is probably rather gradual and the field is
probably a hopeless mess for most of it.
J. Porter Clark
--
J. Porter Clark j...@avdms8.msfc.nasa.gov or j...@gaia.msfc.nasa.gov
NASA/MSFC Flight Data Systems Branch
DaveHatunen
>You have piqued my curiosity. Where did the apparently arbitrary
>conventions of North and South or even East and West come from?
>I always believed the concept of geographic North predated that
>of magnetic North. Perhaps when this is answered it will be TIME
>to seek a new topic regardless of one's geographic position.
>
>Rick "Got-a dime?" Mollenkopf
When the magnet was first discovered to work as a compass, one end was
the "north-seeking" pole, the other the "south-seeking" pole. These
became the N and S poles. By definition, since the opposites attract,
the magnetic pole near the north geographic pole, is a south magnet
pole, not to be confused with the South Magnetic Pole.
Of course the direction North was defined a very long time ago...
although different words were used, like "borealis". So what do you
mean by "the arbitrary conventions of North and South.."?
Ken Wallewein
>Sorry, only one brownie point for you, David. Submarines can and do surface
>in the vicinity of the Pole. In summer, ice-free patches of surface
>occur with some frequency. In summer or winter, a suitably-designed
>submarine can surface through thin ice. US subs do this sort of thing
>now and then.
Oh dear, this is an off day for you Henry. In the part you cut, he's
refering to the *other* pole. I don't think any US subs have surfaced
at the *South Pole*.
Gary
Sorry, I can't resist this ;-)
It reminds me of the old story about WWII ships taking out submarines with
anti-aircraft guns and green paint. Seems they would pour green paint on
the water, and when the subs tried to surface, the paint would coat the
periscope lens so they would think they were still under water and keep
rising. Then the ships would shoot them down with the anti-aircraft guns.
Well, it's _one_ way to get a submarine to the south pole...
/kenw
--
/kenw (as me)
Ken Wallewein
ke...@skyler.arc.ab.ca
(403) 274-7848
Kopal Jha
>the water, and when the subs tried to surface, the paint would coat the
>periscope lens so they would think they were still under water and keep
>rising. Then the ships would shoot them down with the anti-aircraft guns.
They had no pressure guages? Wierd.
Kopal
David Cosenza
Ever forward,
David
--
--------------------------------------------------------------------------
David Cosenza dcos...@netcom.com
PGP Public Key available by finger or upon request
Key fingerprint = FF C1 ED B2 39 1C E7 43 50 B2 F5 64 C3 8F E4 8C
Pat
i suspect the depth gauges weren't supremely accurate. being off by ten feet
put enough of the sail up that one can get some ordinance in it, then they
are screwed.
pat
--
-----------------------------------------------------------------------------
No matter how dire the situation, don't panic -- LLIB #280
Gary Coffman
>In article <1993Dec18.0...@hubcap.clemson.edu> cba...@hubcap.clemson.edu (Charles Allen) writes:
>>What would happen to us if it occurred tomorrow (technologically
>>speaking). Do we still depend on the magnetic field of the earth for
>>anything like navigation, or has the GPS satellites taken over?
>
>Having the poles swap would be a *massive* inconvenience. Magnetic
>compasses are still in very wide use, especially in low-tech applications
>like ocean navigation. (Ordinary GPS receivers, incidentally, will tell
>you position but *not* direction, so you still need a compass of some
>type.) It wouldn't be just a case of cranking in a 180-degree bias,
>because the transition is probably rather gradual and the field is
>probably a hopeless mess for most of it.
GPS does tell you time, 3D position, *direction*, and velocity. My
little handheld tracks well with my speedometer and compass in the
truck. It can't tell direction when it's stationary, but at a walking
pace or higher it is quite good. Ships use *2* GPS receivers, one at
the bow and the other at the stern to give direction. That works even
if you're stationary.
During a field reversal, it appears that the field declines slowly,
remains essentially zero for a fairly long time, and then gradually
builds back up again. By a fairly long time, I mean centuries, not days.
A field reversal should play hob with the Van Allen belts. That would
have consequences for satellites. It would also mess up the navigation
of certain migratory animals. It might have other biological consequences,
that's a matter under dispute.
Henry Spencer
>>Having the poles swap would be a *massive* inconvenience. Magnetic
>> (Ordinary GPS receivers, incidentally, will tell
>
>GPS does tell you time, 3D position, *direction*, and velocity. My
>little handheld tracks well with my speedometer and compass in the
>truck. It can't tell direction when it's stationary, but at a walking
Uh, Gary, this doesn't contradict what I said. It doesn't tell you
direction; rotate the receiver and the reading won't change. It gives
you velocity, as a vector, but won't tell you which way you're pointing
unless that has a known relation to your velocity vector, which is not
necessarily the case.
>Ships use *2* GPS receivers, one at
>the bow and the other at the stern to give direction. That works even
>if you're stationary.
Actually, the sophisticated version of this is GPS interferometry, with
multiple antennas but one (sophisticated) receiver. That's been used
experimentally on aircraft. That's why I said "*ordinary* GPS receivers"
(emphasis added).
>>... It wouldn't be just a case of cranking in a 180-degree bias,
>>because the transition is probably rather gradual and the field is
>>probably a hopeless mess for most of it.
>
>During a field reversal, it appears that the field declines slowly,
>remains essentially zero for a fairly long time, and then gradually
>builds back up again...
However, that's the main field, the dipole field. At full strength,
it dominates the other odds and ends. There is considerable suspicion
that they *don't* shrink to zero when the dipole field does, so they
will dominate during the transition. And they are, um, complicated.
George Herbert
he...@zoo.toronto.edu (Henry Spencer) writes:
>Actually, the sophisticated version of this is GPS interferometry, with
>multiple antennas but one (sophisticated) receiver. That's been used
>experimentally on aircraft. That's why I said "*ordinary* GPS receivers"
>(emphasis added).
I have Trimble ads and info on TANS VECTOR position/attitude system,
which is the same size as their TANS P(Y) box with four antennas
for the interferometry. Things like thing bring joy to small spacecraft
designers like me 8-)
--
george william herbert g...@crl.com
Work: System / Net Administrator, CR Labs Home/Play: Retro Aerospace
KD6WUQ g...@crl.com g...@soda.berkeley.edu gwh@{isu,exec}.isunet.edu
deltaV = g * Isp * ln(Mr) ... it's not just a good idea, it's the Law
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