Detecting people from orbit
Space Cadet
An a human population of 100,000 - 1,000,000
Living in small hunter/gather groups or small agraian groups, spread
out over the whole planet.
If you were in a spacecraft in Low Planetary Orbit
With a full suite of remote sensing gear that is only slightly more
advance that what is commerically available, ie Not military grade
hardware.
1) Asumming that you don't suspect they are their and not actively
looking for them and they don't know you are in orbit and are not
trying to hide themselves
And all you are looking for is a good spot to set down your
colony(ies)/settlement(s)
How easy or hard would it be to detect the presence of hunter/gather
groups or small family farms?
Would thermal imaging systems be able to tell the difference from
human body heat and that of a large native mammal? How big would a
camp/cook fire have to be to be detectible from orbit?
How large would a family garden or cultivated field have to be to be
distinquished from just an ordinary open field?
2)You suspect they are people down on the planet and they don't know
you are there and you are actively looking for them, how hard or easy
would that be?
3)Same as 1, but they somehow know that you are up there, they see a
new 'star' in the sky and reconize it for what it is a ship in orbit
and take efforts to conceal themselves, how hard or easy to do that?
4)You suspect they are down there and they know you are upthere, so
you are actively looking for them, whle they are actively hidding? How
hard or easy would that make things?
Just my $0.02
Keith W of St. Louis AKA Space Cadet
http://www.geocities.com/the_wetzels/
ncw...@hotmail.com
> Given a fully human habitable Earth like world
> An a human population of 100,000 - 1,000,000
> Living in small hunter/gather groups or small agraian groups, spread
> out over the whole planet.
>
> If you were in a spacecraft in Low Planetary Orbit
> With a full suite of remote sensing gear that is only slightly more
> advance that what is commerically available, ie Not military grade
> hardware.
>
That's a strange restriction. An exploration mission is quite likely
to have hardware that is as good as military grade. For example, I
don't think that NASA is restricted to what is commercially
available. In fact, the explorers could well be military.
Cheers,
Nigel.
Charles...@gmail.com
In some cases commercially available sensors are superior to what the
military is using. When it comes to sensors I don't think there is a
meaningful difference between civilian and military, not any more.
johnma...@yahoo.com
> Given a fully human habitable Earth like world
> An a human population of 100,000 - 1,000,000
> Living in small hunter/gather groups or small agraian groups, spread
> out over the whole planet.
>
> If you were in a spacecraft in Low Planetary Orbit
> With a full suite of remote sensing gear that is only slightly more
> advance that what is commerically available, ie Not military grade
> hardware.
>
> 1) Asumming that you don't suspect they are their and not actively
> looking for them and they don't know you are in orbit and are not
> trying to hide themselves
>
> And all you are looking for is a good spot to set down your
> colony(ies)/settlement(s)
>
> How easy or hard would it be to detect the presence of hunter/gather
> groups or small family farms?
It would be very hard to detect the difference between non-
technological humans and non-sapient animals of similar body size from
orbit. If they are at the level of building houses and warming them by
fires, these could be detected from orbit, but might perhaps be
misinterpreted if the observer isn't expecting and looking for them.
But I would think that any reasonable exploration team "looking for is
a good spot to set down your colony(ies)/settlement(s)" would do a
fair amount of surface-level survey, in which framers or even hunter-
gatherers would be quite likely to be noticed.
(You don't make it clear, are the observers assumed to be a different
species then the observed low-tech sapients, or are we to assume a
"lost colony" or something of the sort?)
>
> Would thermal imaging systems be able to tell the difference from
> human body heat and that of a large native mammal?
Not readily. If you explicitly know you are looking for a human, and
know what they look like, visual imagery from orbit could possibly
tell the difference, but if you don't know what the various animals
look like, such observation is not very helpful.
>How big would a
> camp/cook fire have to be to be detectible from orbit?
This depends critically on the exact performance of the sensors, but
more important is how good the analysis programs are. How well can a
campfire be distinguished from random hot spots (stone outcrops heated
in the sun and slow to cool, for example) or lightning-set fires. How
well do the explorers know the detailed environment and what is
plausible there?
> How large would a family garden or cultivated field have to be to be
> distinquished from just an ordinary open field?
There are lots of local, small micro environments in many non-
cultivated settings. For the field to be distinguishable is one thing,
for it to be recognized for what it is, the product of sapient
technology is quite another.
>
> 2)You suspect they are people down on the planet and they don't know
> you are there and you are actively looking for them, how hard or easy
> would that be?
Depends on their tech level, the quality of the sensors, and the
amount of effort you take, and how well you know what to expect. If
they are farmers, and you are looking for farmers, you will probably
find them. Hunter-gatherers, particularly ones that don't use fire,
will be hard to find unless you know exactly what they look like
compared to other animals of similar size.
>
> 3)Same as 1, but they somehow know that you are up there, they see a
> new 'star' in the sky and reconize it for what it is a ship in orbit
> and take efforts to conceal themselves, how hard or easy to do that?
>
If they had legends/memories of high-tech, they might be able to
conceal themselves fairly well, depending on their lifestyle. If they
can stay in caves during daylight, and not make fire outside at night,
they would be quite hard to find for orbit, IMO. But how would they
figure out that that is the way to hide without some fairly accurate
knowledge of tech and what it can and cannot do?
What is the point or context of these various speculations?
-JM
Steven L.
> Given a fully human habitable Earth like world
> An a human population of 100,000 - 1,000,000
> Living in small hunter/gather groups or small agraian groups, spread
> out over the whole planet.
>
> If you were in a spacecraft in Low Planetary Orbit
> With a full suite of remote sensing gear that is only slightly more
> advance that what is commerically available, ie Not military grade
> hardware.
>
> 1) Asumming that you don't suspect they are their and not actively
> looking for them and they don't know you are in orbit and are not
> trying to hide themselves
>
> And all you are looking for is a good spot to set down your
> colony(ies)/settlement(s)
>
> How easy or hard would it be to detect the presence of hunter/gather
> groups or small family farms?
With just the resolution you can get via Google Maps, a small family
farm is real easy to spot from orbit. Just type in the address of a
known farm and see for yourself. There was a farm next door to where I
used to live, and I have had fun looking at a photo of it from space. A
baseball diamond, which is even smaller than a family farm, is easy to
spot from space too.
A hunter-gatherer group wouldn't make its presence known quite as
easily. If they lived in large lodges or large tents, those might just
show up. Yes, you might pick up the thermal imaging from any bonfire
they set. But you wouldn't be able to know if the fire was a naturally
occurring brush fire or not. Naturally occurring brush fires come in
all sizes. Unless you saw it being lit again and again in the same
place, night after night.
> Would thermal imaging systems be able to tell the difference from
> human body heat and that of a large native mammal? How big would a
> camp/cook fire have to be to be detectible from orbit?
> How large would a family garden or cultivated field have to be to be
> distinquished from just an ordinary open field?
Not big at all. It's the *shape* that gives it away--more or less
rectangular or circular, suggesting the human propensity to surveying by
Euclidean geometry, rather than some irregular naturally occurring
shape. Even more so if the field contained irrigation ditches or roads,
which are usually straight.
> 3)Same as 1, but they somehow know that you are up there, they see a
> new 'star' in the sky and reconize it for what it is a ship in orbit
> and take efforts to conceal themselves, how hard or easy to do that?
They could hide themselves, fleeing into a nearby forest or jungle. But
erasing all evidence of their existing civilization would be much tougher.
Like I said, try browsing the satellite photos on Google Maps. You'll
soon see how to tell man-made objects from naturally occurring ones.
--
Steven L.
Email: sdli...@earthlinkNOSPAM.net
Remove the NOSPAM before replying to me.
Peter Bruells
> Space Cadet wrote:
>> How easy or hard would it be to detect the presence of hunter/gather
>> groups or small family farms?
>
> With just the resolution you can get via Google Maps, a small family
> farm is real easy to spot from orbit. Just type in the address of a
> known farm and see for yourself. There was a farm next door to where
> I used to live, and I have had fun looking at a photo of it from
> space. A baseball diamond, which is even smaller than a family farm,
> is easy to spot from space too.
Uncharted worlds seldom come with addresses databases compatible with
Google. :-)
...
> Like I said, try browsing the satellite photos on Google Maps.
> You'll soon see how to tell man-made objects from naturally
> occurring ones.
A very simple experiment would be to try to find low tech villages in
Siberia or the Amazon - only by visual.
Don Bruder
wrote:
> "Steven L." <sdli...@earthlink.net> writes:
>
> > Space Cadet wrote:
>
> >> How easy or hard would it be to detect the presence of hunter/gather
> >> groups or small family farms?
> >
> > With just the resolution you can get via Google Maps, a small family
> > farm is real easy to spot from orbit. Just type in the address of a
> > known farm and see for yourself. There was a farm next door to where
> > I used to live, and I have had fun looking at a photo of it from
> > space. A baseball diamond, which is even smaller than a family farm,
> > is easy to spot from space too.
>
> Uncharted worlds seldom come with addresses databases compatible with
> Google. :-)
However, his point remains valid: With technology no different than what
we have *RIGHT NOW* (AKA "High altitude photography" - the Google
interface just makes the mechanics of doing it easier) it's fairly
trivial to spot cultivated fields and similar macro-objects/features
that are, if not all-out signposts reading "intelligent life somewhere
in this vicinity" in ten foot tall flaming letters, a very strong hint
to take a closer look at the area.
--
Don Bruder - dak...@sonic.net - If your "From:" address isn't on my whitelist,
or the subject of the message doesn't contain the exact text "PopperAndShadow"
somewhere, any message sent to this address will go in the garbage without my
ever knowing it arrived. Sorry... <http://www.sonic.net/~dakidd> for more info
cryptoguy
> In article <m2od5ehjyg....@rogue.de>, Peter Bruells <user...@rogue.de>
> wrote:
>
>
>
>
>
> > "Steven L." <sdlit...@earthlink.net> writes:
>
> > > Space Cadet wrote:
>
> > >> How easy or hard would it be to detect the presence of hunter/gather
> > >> groups or small family farms?
>
> > > With just the resolution you can get via Google Maps, a small family
> > > farm is real easy to spot from orbit. Just type in the address of a
> > > known farm and see for yourself. There was a farm next door to where
> > > I used to live, and I have had fun looking at a photo of it from
> > > space. A baseball diamond, which is even smaller than a family farm,
> > > is easy to spot from space too.
>
> > Uncharted worlds seldom come with addresses databases compatible with
> > Google. :-)
>
> However, his point remains valid: With technology no different than what
> we have *RIGHT NOW* (AKA "High altitude photography" - the Google
> interface just makes the mechanics of doing it easier) it's fairly
> trivial to spot cultivated fields and similar macro-objects/features
> that are, if not all-out signposts reading "intelligent life somewhere
> in this vicinity" in ten foot tall flaming letters, a very strong hint
> to take a closer look at the area.
Most of the 'civilized' portions of the world in Google Earth are
not satellite photos, but aerial. In the portions that are still
satellite. a small population of hunter-gatherers would go
unnoticed, especially in forested areas. Agrarian groups
*might* be noticed, if their fields are large enough, and
enough intelligence examined the right spot.
I can see my car on Google Earth. Twice.
Peter Trei
Peter Bruells
> In article <m2od5eh...@rogue.de>, Peter Bruells <use...@rogue.de>
> wrote:
>
>> Uncharted worlds seldom come with addresses databases compatible with
>> Google. :-)
>
> However, his point remains valid: With technology no different than what
> we have *RIGHT NOW* (AKA "High altitude photography" - the Google
> interface just makes the mechanics of doing it easier) it's fairly
> trivial to spot cultivated fields and similar macro-objects/features
> that are, if not all-out signposts reading "intelligent life somewhere
> in this vicinity" in ten foot tall flaming letters, a very strong hint
> to take a closer look at the area.
It's possible - not trivial. Note that Google concentrates of places
of interest of internet users. Lots of Google-Earth is still unmapped
- even fairly attractive touris places like the small island at the
coast of Northern Germany have a very bad resulation. I tried to find
the remains of a concrete bunker where I used to play. Walls 3 meters
high, 1,5 metres wide, angular shape. Couldn't make it out, the
resolution is too bad.
Also: Clouds. At any given moment large parts of Earth are obcured by
clouds.
It took years to create the data Google is using right now, the
by-product of a fairly large industrial base.
The tech may be sufficient to chart a wild planet and to find
hunter-gatherer groups, but it's simply not trivial. Or rather,
perhaps trivial compared to getting to such a planet.
cryptoguy
I'm not sure of how thorough the coverage is, but goodly
chunks of mars have been photographed at resolutions
of 30 cm by HiRise. You can see the wheel tracks of the
rovers, and the shadows of their instrument masts. For
Phoenix (the polar lander) you can see the two solar
panels. Astonishingly, it managed to capture an image
of Phoenix as it was descending under its parachute.
You could probably make out a human only if he/she
were casting a long shadow, but any dwelling would
be visible.
The satellite portions of Google Earth are at 1m
resolution, far worse. Of course, Mars doesn't have
vegetation cover, and not much in the way of clouds
(it does have occastional dust storms).
Peter Trei
Space Cadet
> That's a strange restriction. An exploration mission is quite likely
> to have hardware that is as good as military grade. For example, I
> don't think that NASA is restricted to what is commercially
> available. In fact, the explorers could well be military.
>
> Cheers,
> Nigel.
anything commericaly available,
but I see that may be in error.
Space Cadet
> On Jul 3, 10:17 am, Space Cadet <kaw...@gmail.com> wrote:
> But I would think that any reasonable exploration team "looking for is
> a good spot to set down your colony(ies)/settlement(s)" would do a
> fair amount of surface-level survey, in which framers or even hunter-
> gatherers would be quite likely to be noticed.
Well, true, but I was assuming a million people, broke up into small
hunter/gather groups,
what is a reasonable size, 100? And then spread them over a large
area, haven't decide if I
should limit them to one major continent or have them spread out over
all the planet.
Depending on where the survey teams land, it might be very easy to
land in an under/unpopulated area
>
> (You don't make it clear, are the observers assumed to be a different
> species then the observed low-tech sapients, or are we to assume a
> "lost colony" or something of the sort?)
Yes they are humans, both groups, inhabitants & the Surveyors
The inhabitants, arrived 200 years ago, they wanted to get away from
opressive Earth gov and very anti-tech back to nature types
SOP at the time was when a colony world was settled colony ship would
deploy a com/relay/beacon sat, over time its orbit degraded and burned
up
years later a SETI tech notice the beacon going silent and incorrectly
assumed
the colony had failed, most colonies would try to retain or build up
their tech
and prior investigations of colonies going silent were the result of
the colony failing
It needs work, but that is what I'm noddling with for now
>
> If they had legends/memories of high-tech, they might be able to
> conceal themselves fairly well, depending on their lifestyle. If they
> can stay in caves during daylight, and not make fire outside at night,
> they would be quite hard to find for orbit, IMO. But how would they
> figure out that that is the way to hide without some fairly accurate
> knowledge of tech and what it can and cannot do?
>
> What is the point or context of these various speculations?
>
> -JM
Well, I wasn't going to make this a lost colony that forgot Earth
They knew where they came from and why their ancestors left Earth
and it was colonist/inhabitants desire to live a simple life and not a
case of backsliding like in so many other stories. Seeing a new
moving
star in the sky and identifying as a ship from Earth might be bit of
stretch
and knowing what the sensors/imaging system can do. They could have
legends
"The Earthers have eyes of an eagle", what would be an appropriate
analog for heat?
Mike Dworetsky
news:dqydnXWnt9JfgvDV...@earthlink.com...
> Space Cadet wrote:
>>
>> How easy or hard would it be to detect the presence of hunter/gather
>> groups or small family farms?
>
> With just the resolution you can get via Google Maps, a small family farm
> is real easy to spot from orbit. Just type in the address of a known farm
> and see for yourself. There was a farm next door to where I used to live,
> and I have had fun looking at a photo of it from space. A baseball
> diamond, which is even smaller than a family farm, is easy to spot from
> space too.
>
> A hunter-gatherer group wouldn't make its presence known quite as easily.
> If they lived in large lodges or large tents, those might just show up.
> Yes, you might pick up the thermal imaging from any bonfire they set. But
> you wouldn't be able to know if the fire was a naturally occurring brush
> fire or not. Naturally occurring brush fires come in all sizes. Unless
> you saw it being lit again and again in the same place, night after night.
>
>
A camp fire or cooking fire outdoors would be easy to spot from orbit by
infrared. Fires are pretty hot. If they stay small they are probably not
natural. On Earth, wild animals tend to stay away from fires, but people
will gather around them. Look for small fires with animal-temperature
bodies huddled around them at night. If the warm bodies keep their
distance then you are seeing wild animals and perhaps a natural source of
fire. Sitting around a fire is one of the oldest human social habits.
Also, by definition a hunter-gatherer tribe does not plant crops.
Hunter-gatherers, well, they hunt, and gather, but they do not cultivate.
--
Mike Dworetsky
(Remove pants sp*mbl*ck to reply)
Quadibloc
> If you were in a spacecraft in Low Planetary Orbit
> With a full suite of remote sensing gear that is only slightly more
> advance that what is commerically available, ie Not military grade
> hardware.
I agree with others that this is an odd restriction. I'd be expecting
a restriction to sensing equipment only slightly more advanced than
achievable with our technology - just to keep the discussion
meaningful; of course, anyone with FTL travel is likely to be *far*
beyond us.
> 1) Asumming that you don't suspect they are their and not actively
> looking for them and they don't know you are in orbit and are not
> trying to hide themselves
>
> And all you are looking for is a good spot to set down your
> colony(ies)/settlement(s)
>
> How easy or hard would it be to detect the presence of hunter/gather
> groups or small family farms?
>
> Would thermal imaging systems be able to tell the difference from
> human body heat and that of a large native mammal? How big would a
> camp/cook fire have to be to be detectible from orbit?
I suspect that even a small fire would be easy to detect from orbit on
a clear day at night, and small fires would be an indication of
intelligent life.
Intelligent aliens versus animals on a planet would be hard to tell
apart without obvious technology; fire probably is it.
John Savard
Howard Brazee
>It would be very hard to detect the difference between non-
>technological humans and non-sapient animals of similar body size from
>orbit. If they are at the level of building houses and warming them by
>fires, these could be detected from orbit, but might perhaps be
>misinterpreted if the observer isn't expecting and looking for them.
The reason we value sapience is because that is our characteristic and
we value humans.
In the past we did not count humans who did not have our technological
ability as being our equals, I suspect we wouldn't find it too hard to
do the same thing with aliens.
David Johnston
<kaw...@gmail.com> wrote:
>Given a fully human habitable Earth like world
>An a human population of 100,000 - 1,000,000
>Living in small hunter/gather groups or small agraian groups, spread
>out over the whole planet.
>
>If you were in a spacecraft in Low Planetary Orbit
>With a full suite of remote sensing gear that is only slightly more
>advance that what is commerically available, ie Not military grade
>hardware.
>
>1) Asumming that you don't suspect they are their and not actively
>looking for them and they don't know you are in orbit and are not
>trying to hide themselves
>
>And all you are looking for is a good spot to set down your
>colony(ies)/settlement(s)
>
>How easy or hard would it be to detect the presence of hunter/gather
>groups or small family farms?
>
>Would thermal imaging systems be able to tell the difference from
>human body heat and that of a large native mammal?
No probably not.
How big would a
>camp/cook fire have to be to be detectible from orbit?
I think a cook fire would be easily detectable from orbit.
>How large would a family garden or cultivated field have to be to be
>distinquished from just an ordinary open field?
We can get a clear picture of a single house and yard from a satellite
now.
>
>2)You suspect they are people down on the planet and they don't know
>you are there and you are actively looking for them, how hard or easy
>would that be?
Pretty easy if they'd passed beyond the hunter-gatherer stage.
Difficult if they hadn't, I think. While campfires could be seen from
orbit they wouldn't necessarily be distinguished from natural fires in
a hurry .
>
>3)Same as 1, but they somehow know that you are up there, they see a
>new 'star' in the sky and reconize it for what it is a ship in orbit
>and take efforts to conceal themselves, how hard or easy to do that?
Impossible if they have permanent surface settlements of more than a
few hundred people.
Robert Martinu
> Intelligent aliens versus animals on a planet would be hard to tell
> apart without obvious technology; fire probably is it.
If they use agriculture radar mapping would give deviating readings for
freshly plowed fields. As this kind of survey would be handy to avoid
landing on a surface that can't support your vessel...
Robert
Don Bruder
wrote:
> Don Bruder <dak...@sonic.net> writes:
>
> > In article <m2od5eh...@rogue.de>, Peter Bruells <use...@rogue.de>
> > wrote:
> >
> >> Uncharted worlds seldom come with addresses databases compatible with
> >> Google. :-)
> >
> > However, his point remains valid: With technology no different than what
> > we have *RIGHT NOW* (AKA "High altitude photography" - the Google
> > interface just makes the mechanics of doing it easier) it's fairly
> > trivial to spot cultivated fields and similar macro-objects/features
> > that are, if not all-out signposts reading "intelligent life somewhere
> > in this vicinity" in ten foot tall flaming letters, a very strong hint
> > to take a closer look at the area.
>
> It's possible - not trivial. Note that Google concentrates of places
> of interest of internet users. Lots of Google-Earth is still unmapped
> - even fairly attractive touris places like the small island at the
> coast of Northern Germany have a very bad resulation.
I'd hazard a guess that more than half of the "bad resolution" areas are
political at the source - Much of my hometown, for instance, is (quite
obviously deliberately) "fogged out" on Google Earth. Not because they
don't have good quality images - In one area, the "fog" starts in the
middle of a mosaic piece that includes my childhood home. The part of
the tile that contains said home is so crystal clear that I can almost
count the shingles on the roof of the house. And I *CAN* count the
elements of the TV antenna on the roof. Hell, I can even see the remains
of the tree-fort I built 30-some-years ago in the old tree in teh back
yard. However, a few hundred yards away, which, coincidentally, is
pretty darn close to being the exact location of the "City Limits" sign
just up the road, the "fog" picks up, and it's literally impossible to
tell if "that darkish blob" is the next-door-neighbor's house, or a
tree...
Why would a city be fogged out like that? Hmmm... Could it have
something to do with the fact that said city is the home port of a piece
of pretty high-end hardware that would make a decent target should one
want to hamstring a *MAJOR* shipping channel? ("MAJOR" as in knocking
out that piece of hardware, even for a short time, would have a
potentially devastating impact on multiple BILLIONS of dollars worth of
national and international commerce)
We also know (not suppose - KNOW) that Google deliberately fogs out the
data on request of various agencies - Try getting a clear view of
various military bases, for example - You can't - You get the fogged-out
version.
Assuming the image quality that is *KNOWN* to be available were used in
all locations, locating cultivated areas would be, as I said, trivial.
David DeLaney
>Well, I wasn't going to make this a lost colony that forgot Earth
>They knew where they came from and why their ancestors left Earth
>and it was colonist/inhabitants desire to live a simple life and not a
>case of backsliding like in so many other stories.
Just remember that the colonists are gonna have kids, and those kids are gonna
have kids, and there's no real way to make sure that the original colonists'
desires get inherited at the same level...
>They could have legends
>"The Earthers have eyes of an eagle", what would be an appropriate
>analog for heat?
Rattlesnake / pit viper.
Dave
--
\/David DeLaney posting from d...@vic.com "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
http://www.vic.com/~dbd/ - net.legends FAQ & Magic / I WUV you in all CAPS! --K.
Jacey Bedford
<sdli...@earthlink.net> writes
>With just the resolution you can get via Google Maps, a small family
>farm is real easy to spot from orbit. Just type in the address of a
>known farm and see for yourself. There was a farm next door to where I
>used to live, and I have had fun looking at a photo of it from space.
>A baseball diamond, which is even smaller than a family farm, is easy
>to spot from space too.
Hell, you can spot our red car on google earth and the small patch of
lawn that got burned off when we had a bonfire after chopping down a
dead tree. The patch is only three or four feet across.
Jacey
--
Jacey Bedford
jacey at artisan hyphen harmony dot com
posting via usenet and not googlegroups, ourdebate
or any other forum that reprints usenet posts as
though they were the forum's own
Quadibloc
> In the past we did not count humans who did not have our technological
> ability as being our equals, I suspect we wouldn't find it too hard to
> do the same thing with aliens.
I think we will be on our best behavior in space. But we will leave
aliens alone whose status is indeterminate. After all, aliens being
_alien_, to be able to tell if they're reasoning beings, we may well
need something obvious like technological ability.
John Savard
Space Cadet
> On Thu, 3 Jul 2008 13:54:38 -0700 (PDT), Space Cadet <kaw...@gmail.com> wrote:
> >Well, I wasn't going to make this a lost colony that forgot Earth
> >They knew where they came from and why their ancestors left Earth
> >and it was colonist/inhabitants desire to live a simple life and not a
> >case of backsliding like in so many other stories.
>
> Just remember that the colonists are gonna have kids, and those kids are gonna
> have kids, and there's no real way to make sure that the original colonists'
> desires get inherited at the same level...
knowledge of living off the land and no other works, like chemistry,
mathematics or physic texts and the original colonist have no desire
to pass that on or expertise in those fields. Then the next generation
or so, would have to start from scratch. Yes they could go to farming
and small settlements, but all pretty much preindustrial.
Just my $0.02
Keith W of St. Louis AKA Space Cadet
http://www.geocities.com/the_wetzels/
>
> >They could have legends
> >"The Earthers have eyes of an eagle", what would be an appropriate
> >analog for heat?
>
> Rattlesnake / pit viper.
>
> Dave
> --
> \/David DeLaney posting from d...@vic.com "It's not the pot that grows the flower
> It's not the clock that slows the hour The definition's plain for anyone to see
> Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>http://www.vic.com/~dbd/- net.legends FAQ & Magic / I WUV you in all CAPS! --K.
Mark Zenier
Space Cadet <kaw...@gmail.com> wrote:
>Given a fully human habitable Earth like world
>An a human population of 100,000 - 1,000,000
>Living in small hunter/gather groups or small agraian groups, spread
>out over the whole planet.
>
>If you were in a spacecraft in Low Planetary Orbit
>With a full suite of remote sensing gear that is only slightly more
>advance that what is commerically available, ie Not military grade
>hardware.
Military grade = 10 centimeters, Commercial grade = 1 to 3 meter resolution.
Not that much difference.
>1) Asumming that you don't suspect they are their and not actively
>looking for them and they don't know you are in orbit and are not
>trying to hide themselves
>
>And all you are looking for is a good spot to set down your
>colony(ies)/settlement(s)
>
>How easy or hard would it be to detect the presence of hunter/gather
>groups or small family farms?
If they use slash and burn agriculture, you could probably detect
them from Mars, or with the naked eye, as has been show by some
of those "the world at night" whole earth pictures.
>Would thermal imaging systems be able to tell the difference from
>human body heat and that of a large native mammal?
Probably not from orbit.
>How big would a
>camp/cook fire have to be to be detectible from orbit?
Even a small campfire is a couple of kilowatts of near-infared.
Check out what they use for detecting hidden hot spots after forest
fires, although I think those are on aircraft.
>How large would a family garden or cultivated field have to be to be
>distinquished from just an ordinary open field?
By comparing pictures taken over time, very small. One day there's
a fallow field, next week it's ploughed. Or harvested. Or a block
of woodland is felled in time to make up the winter's woodpile.
Or a herd of large animals take an unpredictable path from one
area to another with good grazing. Or an area is burned without
any possible lightning occuring in the area when it ignited.
>2)You suspect they are people down on the planet and they don't know
>you are there and you are actively looking for them, how hard or easy
>would that be?
If you have time, very easy.
>3)Same as 1, but they somehow know that you are up there, they see a
>new 'star' in the sky and reconize it for what it is a ship in orbit
>and take efforts to conceal themselves, how hard or easy to do that?
By then, it's probably too late, as agriculture has time cycles.
For hunter gatherers, optical resolution is high enough that you can
see people or groups of people. That makes going out into the
field and digging up tubers a bit difficult unless the population
is not identified by species and the observers have to figure out
if they're intelligent or not.
>4)You suspect they are down there and they know you are upthere, so
>you are actively looking for them, whle they are actively hidding? How
>hard or easy would that make things?
I remember a couple examples of this in SF,
one was in L. Sprague De Camp's _Divide and Rule_, where the underground
was living in the woods using container gardens. Another was in one
of John Barnes "Resuna?" books (that I could not finish).
Or, look at how the professional dope farmers do it.
Mark Zenier mze...@eskimo.com
Googleproofaddress(account:mzenier provider:eskimo domain:com)
Crown-Horned Snorkack
> In article <19edbbd9-9bf0-46d2-932e-4e3d34c6f...@u36g2000prf.googlegroups.com>,
them, and additional reasons to avoid if you are hiding deliberately.
> >2)You suspect they are people down on the planet and they don't know
> >you are there and you are actively looking for them, how hard or easy
> >would that be?
>
> If you have time, very easy.
>
> >3)Same as 1, but they somehow know that you are up there, they see a
> >new 'star' in the sky and reconize it for what it is a ship in orbit
> >and take efforts to conceal themselves, how hard or easy to do that?
>
> By then, it's probably too late, as agriculture has time cycles.
> For hunter gatherers, optical resolution is high enough that you can
> see people or groups of people. That makes going out into the
> field and digging up tubers a bit difficult unless the population
> is not identified by species and the observers have to figure out
> if they're intelligent or not.
>
> >4)You suspect they are down there and they know you are upthere, so
> >you are actively looking for them, whle they are actively hidding? How
> >hard or easy would that make things?
>
> I remember a couple examples of this in SF,
> one was in L. Sprague De Camp's _Divide and Rule_, where the underground
> was living in the woods using container gardens. Another was in one
> of John Barnes "Resuna?" books (that I could not finish).
>
> Or, look at how the professional dope farmers do it.
>
Viet Nam Cong San were busy defeating air photography. Then there are
the Yahi of California, who lived before aircraft, but did deal with
threat of being seen from mountaintops.
Scott Fluhrer
"Space Cadet" <kaw...@gmail.com> wrote in message
news:19edbbd9-9bf0-46d2...@u36g2000prf.googlegroups.com...
> Given a fully human habitable Earth like world
> An a human population of 100,000 - 1,000,000
> Living in small hunter/gather groups or small agraian groups, spread
> out over the whole planet.
>
> If you were in a spacecraft in Low Planetary Orbit
> With a full suite of remote sensing gear that is only slightly more
> advance that what is commerically available, ie Not military grade
> hardware.
>
> 1) Asumming that you don't suspect they are their and not actively
> looking for them and they don't know you are in orbit and are not
> trying to hide themselves
>
> And all you are looking for is a good spot to set down your
> colony(ies)/settlement(s)
>
> How easy or hard would it be to detect the presence of hunter/gather
> groups or small family farms?
>
> Would thermal imaging systems be able to tell the difference from
> human body heat and that of a large native mammal? How big would a
> camp/cook fire have to be to be detectible from orbit?
> How large would a family garden or cultivated field have to be to be
> distinquished from just an ordinary open field?
One of the things that I suspect people have missed on this thread is just
how big a planet is, and how easily a group this size can get lost in the
vastness (unless the people in the spacecraft is looking *very* carefully
for them). The Earth has a land mass of 149 million square kilometers, a
high resolution photo (high enough to be able to distinguish things that
would indicate sapience) might cover 1 square kilometer (and military grade
resolution won't help; you'll see an even smaller area to better
resolution). Unless you happen to hit (and analyze) one of the few square
kilometers that happen to have some evidence, you'll never see it via
orbiting photography.
On the other hand, Space Cadet did specify that this was a recolonization
mission; the new mission knows that there was a previous mission that
apparently failed. I would expect that one of the goals of the
recolonization mission would be to determine why the first mission 'failed'
(it might be something quite pertinent, such as a disease endemic to that
planet, or a subtle toxin that is fatal over a period of decades), and so I
would expect them to make an attempt to find the first landing site (if they
don't know where that is already). I would expect some of the remaining
humans to be not that far from that site (unless the author Space Cadet
gives some specific reason why not).
--
poncho
Crown-Horned Snorkack
If you want to land a spacecraft on an uninhabited planet, what you
want is quite likely an empty field with flat and firm surface - which
is already lacking large plants like trees or bushes. Preferrably in a
region where you can rely on lack of clouds and good visibility most
of time.
But when you want a reliable year-round supply of food with low
technology, you would likely pick a place with year round sufficient
precipitation, where plants grow well.
Which means that once the colonists have landed and no longer depend
on their initial landing field to unload their supplies, they better
leave the place and move somewhere they can live. Which would be some
distance away, and not necessarily obvious from the landing field.
W. Citoan
Those two areas are not necessarily mutually exclusive. Prairies provide
both.
- W. Citoan
--
My center is giving way, my right is in retreat, situation excellent. I
attack!
-- [General] Ferdinand Foch
William December Starr
d...@gatekeeper.vic.com (David DeLaney) said:
> Space Cadet <kaw...@gmail.com> wrote:
>
>> Well, I wasn't going to make this a lost colony that forgot Earth
>> They knew where they came from and why their ancestors left Earth
>> and it was colonist/inhabitants desire to live a simple life and
>> not a case of backsliding like in so many other stories.
>
> Just remember that the colonists are gonna have kids, and those
> kids are gonna have kids, and there's no real way to make sure
> that the original colonists' desires get inherited at the same
> level...
And eventually one of 'em's going to be so pissed at his ancestors
that he'll build a time machine and...
--
William December Starr <wds...@panix.com>
William December Starr
Quadibloc <jsa...@ecn.ab.ca> said:
"We?" Only for -- at best -- as long as one bloc of humanity has a
monoloy on space travel, or at least on the power to act as "space
cops" on all space-traveling humans.
William December Starr
Don Bruder <dak...@sonic.net> said:
> Why would a city be fogged out like that [in Google Earth]?
> Hmmm... Could it have something to do with the fact that said city
> is the home port of a piece of pretty high-end hardware that would
> make a decent target should one want to hamstring a *MAJOR*
> shipping channel? ("MAJOR" as in knocking out that piece of
> hardware, even for a short time, would have a potentially
> devastating impact on multiple BILLIONS of dollars worth of
> national and international commerce)
What are we talking about here, a mongo dredge? (It doesn't seem to
me -- an utter non-expert in modern water shipping -- that any
_single_ loading crane, no matter how large or sophisticated, would
be a major bottleneck point, but I could be wrong.)
John F. Eldredge
Presumably this piece of equipment would block the shipping channel. Are
there any major ports upstream of shipping locks, such that disabling the
lock, or sinking a ship passing through it, would deny access to the
lock? Disabling the Panama Canal would be a major inconvenience, but
there aren't any major ports within the Canal itself.
There are a lot of harbors that have only one good deep-water route in
and out of them that avoids underwater obstructions. Blocking such a
port by sinking a ship in the channel is a technique that has been around
for a long time, but Don Bruder's description doesn't sound like that is
what he means.
--
John F. Eldredge -- jo...@jfeldredge.com
PGP key available from http://pgp.mit.edu
"Reserve your right to think, for even to think wrongly is better
than not to think at all." -- Hypatia of Alexandria
Don Bruder
Think "Mackinac" - The icebreaker that singlehandedly keeps idiotic
numbers of dollars worth of commerce flowing on the Great Lakes shipping
lanes in early spring and late fall, and during the rest of the year,
keeps the majority of the navigational gear on the lakes in working
order. The mouth of the Cheboygan River, in Cheboygan MI, is the
Mackinac's home port.
Put that one ship out of commission, and shipping on the Great Lakes may
not grind to a complete halt, but it will be *SEVERELY* impacted. Fuel,
iron and copper ore, bulk transport, just to name the most obvious. Both
American and Canadian traffic will be hit, and hit hard. Do it in late
spring or at the height of summer (anytime after the spring breakout),
and the impact will be smaller, but it will anything *EXCEPT*
insignificant. Do it in about November, and depending on exactly what
the winter freeze does that year, you'll TOTALLY wipe out anywhere from
4 to 6 months worth of shipping as the boats have to wait for spring
breakout to happen "whenever it decides to happen". That includes the
Mac breaking out the Soo locks in the spring - Until she gets there to
do that, shipping is trapped on one side or the other. (And this ignores
the lost/broken down/etc buoys the Mac takes care of during
"non-icebreaking" time, as well as other support work it wouldn't be
able to do that would affect, either directly or indirectly, most, if
not all, commercial shipping on the Great Lakes)
Jesper Lauridsen
>
> Military grade = 10 centimeters, Commercial grade = 1 to 3 meter resolution.
> Not that much difference.
A factor of 10-30 isn't a big difference?
Robert Martinu
But what causes the difference?
Military sats get their resolution by flying as deep as possible, at the
expense of service length. A company operating on the legit side would
get the same data quality for much less money by strapping a camera onto
a plane. Using a sat only makes commercial sense if you want to monitor
large areas over a long period.
Robert
Steven L.
> Don Bruder <dak...@sonic.net> writes:
>
>> In article <m2od5eh...@rogue.de>, Peter Bruells <use...@rogue.de>
>> wrote:
>>
>>> Uncharted worlds seldom come with addresses databases compatible with
>>> Google. :-)
>> However, his point remains valid: With technology no different than what
>> we have *RIGHT NOW* (AKA "High altitude photography" - the Google
>> interface just makes the mechanics of doing it easier) it's fairly
>> trivial to spot cultivated fields and similar macro-objects/features
>> that are, if not all-out signposts reading "intelligent life somewhere
>> in this vicinity" in ten foot tall flaming letters, a very strong hint
>> to take a closer look at the area.
>
> It's possible - not trivial. Note that Google concentrates of places
> of interest of internet users. Lots of Google-Earth is still unmapped
> - even fairly attractive touris places like the small island at the
> the remains of a concrete bunker where I used to play. Walls 3 meters
> high, 1,5 metres wide, angular shape. Couldn't make it out, the
> resolution is too bad.
>
> clouds.
That's only because Google Maps uses imagery in the visible spectrum.
The planet Venus is *completely* obscured by clouds, nearly 100% of the
time. But it's been totally mapped by radar. An advanced space-faring
civilization would necessarily survey a new planet with imagery gathered
from all up and down the EM spectrum, from ultraviolet out to radio waves.
Before GPS, cruise missiles navigated to the target by radar maps stored
in their computer memories and matched against returns from its onboard
radar.
--
Steven L.
Email: sdli...@earthlinkNOSPAM.net
Remove the NOSPAM before replying to me.
Steven L.
> I suspect that even a small fire would be easy to detect from orbit on
> a clear day at night, and small fires would be an indication of
> intelligent life.
No, I've seen plenty of small natural brush fires burning in isolated
areas for long periods without spreading. That wouldn't be conclusive
by itself. OTOH, if the fire was observed to go out and then restart in
exactly the same location the following night, that would be more revealing.
> Intelligent aliens versus animals on a planet would be hard to tell
> apart without obvious technology; fire probably is it.
It would even be hard to tell them apart even if you met them face to face.
We're still not sure just how intelligent dolphins are, even though
we've been observing them for centuries. They have almost no technology
to analyze, and we can't get inside their minds to know what they are
thinking. Recently, dolphins have been observed using sponges as
primitive tools, comparable to how chimpanzees use sticks as primitive
tools. So after all these centuries, we might be able to conclude that
dolphins are roughly as smart as chimps.
The very first hominids on earth, Australopithecus afarensis, were
basically apes that learned how to walk upright, but were otherwise
ape-like.
http://en.wikipedia.org/wiki/Image:A.afarensis.jpg
Do you want to think of them as animals or as intelligent persons?
Steven L.
If they traveled far from their original planned landing site, they
would likely leave records and markers to let anyone else know who might
follow them where they went. Heck, they might even leave a radio
transmitter as a beacon to mark their original landing point, so anyone
else could follow them from there.
Remember, this is still an advanced spacefaring culture that is
colonizing this new world, not a bunch of primitive hunter-gatherers who
just move nomadically from place to place at will.
Space Cadet
> Remove the NOSPAM before replying to me.
Well maybe Hunter/Gathers are the wrong analogy
The story I'm working on, the first set of colonist that settled this
world
are back to nature types, think Amish or any group that is not
interested in
technology, they want to 'live in harmony with nature', bring along
any advance tech
to their new home is the last thing they would do. They left Earth
because it was
becoming to industrial/technological for their tastes/religious
beliefs and or philosophies
Leaving markers behind for anyone to follow, is something I hadn't
considered yet.
They would welcome anyone who shared their worldview, but anyone else
would not be
welcome
Just my $0.02
Michael Stemper
Something that Piper played off of in _Little Fuzzy_, where the rule
of "talks and builds fires" nearly let a genocide happen.
--
Michael F. Stemper
Nostalgia just ain't what it used to be.
Crown-Horned Snorkack
around 100 people to Roanoke and Northwest Passage. Both vanished into
mystery.
The Roanoke colonists left just word "Croatoan" carved into a tree.
When, 20 years later, the English settled in Virginia and came to
explore and trade with surrounding native, they should have spoken to
the natives around Roanoke Colony. But they heard nothing.
Franklin expedition, with 105 surviving members as of 25th of April,
1848 and plenty of writing material, vanished into mystery after
Victory Point record. Many of their things can be found, and many
bones (many of them cannibalized) but no writings about what had
happened.
> > --
> > Steven L.
> > Email: sdlit...@earthlinkNOSPAM.net
> > Remove the NOSPAM before replying to me.
>
> Well maybe Hunter/Gathers are the wrong analogy
> The story I'm working on, the first set of colonist that settled this
> world
> are back to nature types, think Amish or any group that is not
> interested in
> technology, they want to 'live in harmony with nature', bring along
> any advance tech
> to their new home is the last thing they would do. They left Earth
> because it was
> becoming to industrial/technological for their tastes/religious
> beliefs and or philosophies
> Leaving markers behind for anyone to follow, is something I hadn't
> considered yet.
> They would welcome anyone who shared their worldview, but anyone else
> would not be
> welcome
>
One logical move would be deliberately not leaving markers. They could
have strong reasons not to want to be found by a rescue expedition.
Like, evading responsibility for mutiny and murder.
Obliterating all trace of original settlement would be hard. But if a
large settlement is destroyed, with some groups setting out in various
direction to escape (and fail), other groups attacking each other with
violence, one would not be surprised if not all human remains can be
accounted for. If a settlement is destroyed by starvation, it is not
unlikely that there would be some violence. 200 years later, it would
be very hard to unravel the sequence of events, especially if any
official records at obvious places are deliberate target for violence.
We have a range of 100 000 to 1 000 000 people in total after 2
centuries. A well fed population could grow 100 times in 2 centuries -
like the French of Quebec, who started at 60 000 in 1759. So, if we
have a minimum of 1000 survivors when the original colony is destroyed
and they, like the settlers of Pitcairn, loot and destroy the original
official colony and kill any who are unwilling to join - then move to
a distant corner of the planet and start over with hard to detect
hunting, gathering and gardening economy - what would a rescue
expedition find in 200 years?
Remus Shepherd
In rec.arts.sf.science Space Cadet <kaw...@gmail.com> wrote:
> Given a fully human habitable Earth like world
> An a human population of 100,000 - 1,000,000
> Living in small hunter/gather groups or small agraian groups, spread
> out over the whole planet.
> If you were in a spacecraft in Low Planetary Orbit
> With a full suite of remote sensing gear that is only slightly more
> advance that what is commerically available, ie Not military grade
> hardware.
Commercial satellites now have better than one meter resolution in
visible bands. Thermal isn't in vogue right now, but we could probably
make a 5 meter thermal instrument if we wanted.
> 1) Asumming that you don't suspect they are their and not actively
> looking for them and they don't know you are in orbit and are not
> trying to hide themselves
> And all you are looking for is a good spot to set down your
> colony(ies)/settlement(s)
> How easy or hard would it be to detect the presence of hunter/gather
> groups or small family farms?
Trivial, given enough time.
Almost impossible, in less than a full planetary year.
> Would thermal imaging systems be able to tell the difference from
> human body heat and that of a large native mammal?
No, not at this resolution.
> How big would a
> camp/cook fire have to be to be detectible from orbit?
A small boy scout troop can make a camp fire viewable by orbit. But
fires on that scale pop up all the time, from lightning strikes or
dew lensing. Detecting the traces of human habitation are not a problem.
The problem is distinguishing them from natural changes.
> How large would a family garden or cultivated field have to be to be
> distinquished from just an ordinary open field?
Size doesn't matter. What matters here is whether the field is a
regular shape -- square, rectangle, circle, etc. Many farmers have
irregular fields (not so much in the USA, but plenty elsewhere), and
they can be hard to tell apart from normal terrain.
> 2)You suspect they are people down on the planet and they don't know
> you are there and you are actively looking for them, how hard or easy
> would that be?
If you're talking about identifying specific individuals, that's going
to be difficult. Identifying that there are human beings down there is
easy once your sensor runs over them. But you might miss a small settlement
the first dozen times you run over the area.
> 3)Same as 1, but they somehow know that you are up there, they see a
> new 'star' in the sky and reconize it for what it is a ship in orbit
> and take efforts to conceal themselves, how hard or easy to do that?
The only effective concealment is living underground or in a dense
forest canopy.
> 4)You suspect they are down there and they know you are upthere, so
> you are actively looking for them, whle they are actively hidding? How
> hard or easy would that make things?
At this point we're warring with competing technologies. There are
sensors that can look through forest canopies, and camoflauge technology
that can defeat it. It'll come down to whose technology is better.
... ...
Remus Shepherd <re...@panix.com>
Journal: http://www.livejournal.com/users/remus_shepherd/
Comic: http://indepos.comicgenesis.com/
rick++
Globe).
Thats not top of the line technology for the 20th century or what
will possible in future decades.
What I see are in Google are two-meter shadows of walking people
if the photo is taken early or late in the day.
Derek Lyons
>I can see people directly in Google Satellite pictures (Digital
>Globe). Thats not top of the line technology for the 20th century
>or what will possible in future decades.
The high resolution photos in GE and GM where you can see people
aren't satellite pictures - but are ariel shots.
D.
--
Touch-twice life. Eat. Drink. Laugh.
http://derekl1963.livejournal.com/
-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL
Derek Lyons
>Why would a city be fogged out like that? Hmmm... Could it have
>something to do with the fact that said city is the home port of a piece
>of pretty high-end hardware that would make a decent target should one
>want to hamstring a *MAJOR* shipping channel?
No.
Wayne Throop
: The high resolution photos in GE and GM where you can see people
: aren't satellite pictures - but are ariel shots.
Which maybe suggests a method; if you want to detect things from orbit,
insert a fleet of disposable [mini/micro/nano] sized UAVs with appropriate
sensor suites. One could argue that that doesn't count as "from orbit",
but it doesn't seem totally clear that it shouldn't count. As the various
bits of widgetry needed for digital optics get cheaper andcheaper, it
might well become attractive to throw disposable 'bots at the problem.
Xref the gear deployed for ubiquitous surveilence by the Tinkers in the
"across realtime" series, or the dustmote-sized sensor/locators used by
Pham against the Emergency in the "zones-o-thought" setting. Of course,
the large area to cover might render it impractical, depending on details
of who's doing the detecting, and what assets they have in orbit, and
how little they've progressed beyond current tech in the scenario at hand.
Wayne Throop thr...@sheol.org http://sheol.org/throopw
Chuk Goodin
>> camp/cook fire have to be to be detectible from orbit?
>
> A small boy scout troop can make a camp fire viewable by orbit. But
>fires on that scale pop up all the time, from lightning strikes or
>dew lensing. Detecting the traces of human habitation are not a problem.
>The problem is distinguishing them from natural changes.
Dew lensing? Like, dewdrops concentrating sunlight until it starts fires?
Wouldn't that be pretty unlikely? And if it did happen, wouldn't the fuel
be wet with dew and less likely to ignite?
--
chuk
Luke Campbell
> Commercial satellites now have better than one meter resolution in
> visible bands. Thermal isn't in vogue right now, but we could probably
> make a 5 meter thermal instrument if we wanted.
The infrared light emitted by body heat that can get through the air
is in the 8 to 15 micron wavelength range. Visible light is 0.7 to
0.4 microns, or about 20 times shorter. So if you keep the scope the
same size, your resolution will be about 20 times poorer. With 1
meter resolution in the visible, you would be looking at 20 meter
resolution in the far infrared. Alternately, if you really want 5
meter resolution, build your scope with a primary mirror that is 4
times larger.
Hot things (as opposed to merely warm things) emit a fair amount of
mid infrared light that can get through the atmospheric window at 3.5
to 4 microns. This is about 7 times lower resolution than with
visible, so your 1 meter resolution scope would have a resolution of 7
meters in the mid IR. You could use this on vehicle engines, jet
exhaust openings, boilers, kilns, furnaces, ovens, and chimneys, at
least those which are not covered by a roof or other obstruction (hard
to do with chimneys).
You could probably get good IR resolution using a synthetic aperture -
take four scopes like you use for visible light, and space them twenty
times further apart than their primary mirror apertures to get the
same resolution you get in the visible. Since adaptive optics to
correct for atmospheric twinkling is easier in the infrared than in
the visible, you might even get better resolution in the infrared this
way. On the other hand, if you use this as a visible interferometer,
you also get 20 times better visible resolution if you can correct for
atmospheric twinkling.
Luke
Remus Shepherd
> On Jul 7, 4:29 pm, Remus Shepherd <re...@panix.com> wrote:
> > Commercial satellites now have better than one meter resolution in
> > visible bands. Thermal isn't in vogue right now, but we could probably
> > make a 5 meter thermal instrument if we wanted.
> The infrared light emitted by body heat that can get through the air
> is in the 8 to 15 micron wavelength range. Visible light is 0.7 to
> 0.4 microns, or about 20 times shorter. So if you keep the scope the
> same size, your resolution will be about 20 times poorer. With 1
> meter resolution in the visible, you would be looking at 20 meter
> resolution in the far infrared. Alternately, if you really want 5
> meter resolution, build your scope with a primary mirror that is 4
> times larger.
I agree completely with your calculations. However, I have worked with
high resolution thermal (10-11 micron) satellite imagery some years ago.
It was not commercial, but I'm sure we could make a commercial version by now
if we wished. Nobody wishes to, though -- there's no app for it.
> Hot things (as opposed to merely warm things) emit a fair amount of
> mid infrared light that can get through the atmospheric window at 3.5
> to 4 microns.
Yeah, but the atmospheric transmittance is terrible in those wavelengths.
This might be a solution for aerial reconnaissance, but not satellites.
Remus Shepherd
> Interesting. Apparently the atmosphere was sufficiently transparent
> in 1997 over New Mexico for a megawatt test laser (MIRACL) emitting a
> 3.8 micron beam to disable an orbiting satellite, but maybe that's a
> consequence of having megawatts to throw around (and the extent of the
> damage to the satellite was never made public, maybe it was merely
> blinded).
Lasers and detectors are different beasts. It's easy to tune a laser
to a specific, tight wavelength. Building a detector to see that wavelength
may be much more difficult, and detectors are guaranteed to have wider
bandwidths than lasers. I don't know how hard it is to make detectors in
the 3.5-4 micron range without dipping into the slop from 3.0-3.5, but I
bet it's a challenge.
> I also know that's the band heat seeking missiles use to
> home in on their targets.
I didn't know that -- cool.
> Maybe it is too variable with atmospheric conditions to be reliably
> useful?
Or maybe I'm just plain wrong. :) Looking into it further, I see that
both GOES and MODIS use a 3.9 micron SWIR band for fire detection. However,
they only use it in conjunction with an 11 micron band, which leads me to
think there is something limiting the utility of the SWIR band. The GOES
site says that it also views smoke, so maybe that's the problem -- unlike
the thermal band, the 3.9 band can be obscured by smoke from the fire it's
trying to detect.
> Landsat 7 observed at 8 spectral bands, including 10.4 to
> 12.5 microns and 2.09 to 2.35 microns (the latter somewhat surprising
> to me, I thought the air was mostly opaque at around 2 microns) but
> they apparently bypassed the 3.5 to 4 micron window.
Heh. Landsat 7 is the satellite I work on. Which goes to show my bias --
if the data is from a band greater than 2.5 microns, it can't be worth
anything. ;)
L7 probably skipped the longwave SWIR bands because the program is very
concerned with historical continuity. They are still emulating the bands
from the first TM instrument on L4. The next Landsat satellite will emulate
the same bands, although thankfully they're adding bands for detection of
cirrus and aerosols.
Luke Campbell
Interesting. Apparently the atmosphere was sufficiently transparent
in 1997 over New Mexico for a megawatt test laser (MIRACL) emitting a
3.8 micron beam to disable an orbiting satellite, but maybe that's a
consequence of having megawatts to throw around (and the extent of the
damage to the satellite was never made public, maybe it was merely
blinded). I also know that's the band heat seeking missiles use to
home in on their targets. This figure seems to show pretty good
ground to space transparency of 3.5 to 4 micron light
http://www.informit.com/content/images/chap3_067232248x/elementLinks/03fig02.gif
Maybe it is too variable with atmospheric conditions to be reliably
useful? Landsat 7 observed at 8 spectral bands, including 10.4 to
12.5 microns and 2.09 to 2.35 microns (the latter somewhat surprising
to me, I thought the air was mostly opaque at around 2 microns) but
they apparently bypassed the 3.5 to 4 micron window.
http://landsat.gsfc.nasa.gov/about/etm+.html
Luke
Luke Campbell
> In rec.arts.sf.science Luke Campbell <lwc...@gmail.com> wrote:
>
> Lasers and detectors are different beasts. It's easy to tune a laser
> to a specific, tight wavelength. Building a detector to see that wavelength
> may be much more difficult, and detectors are guaranteed to have wider
> bandwidths than lasers. I don't know how hard it is to make detectors in
> the 3.5-4 micron range without dipping into the slop from 3.0-3.5, but I
> bet it's a challenge.
If your detector was sensitive to the band from 3 to 4 microns, and
there is no radiation to see at 3 to 3.5 microns, it doesn't really
hurt you any, does it? Maybe the band is too narrow to get sufficient
power collected for most applications (at least not without a big
mirror).
> Looking into it further, I see that
> both GOES and MODIS use a 3.9 micron SWIR band for fire detection. However,
> they only use it in conjunction with an 11 micron band, which leads me to
> think there is something limiting the utility of the SWIR band. The GOES
> site says that it also views smoke, so maybe that's the problem -- unlike
> the thermal band, the 3.9 band can be obscured by smoke from the fire it's
> trying to detect.
Smoke is an interesting problem - if it can absorb at 3.5-4 microns,
it can also radiate in the same band. If it cools off by mixing with
the air it could form an insulating blanket around the flame and
prevent its radiation from getting out, but if it forms a hot plume it
should also be visible in the mid infrared. I don't know which of
these is more typical.
> > Landsat 7 observed at 8 spectral bands, including 10.4 to
> > 12.5 microns and 2.09 to 2.35 microns (the latter somewhat surprising
> > to me, I thought the air was mostly opaque at around 2 microns) but
> > they apparently bypassed the 3.5 to 4 micron window.
>
> Heh. Landsat 7 is the satellite I work on.
COOL!
Luke
Remus Shepherd
> On Jul 9, 9:47 am, Remus Shepherd <re...@panix.com> wrote:
> > In rec.arts.sf.science Luke Campbell <lwc...@gmail.com> wrote:
> > Lasers and detectors are different beasts. It's easy to tune a laser
> > to a specific, tight wavelength. Building a detector to see that wavelength
> > may be much more difficult, and detectors are guaranteed to have wider
> > bandwidths than lasers. I don't know how hard it is to make detectors in
> > the 3.5-4 micron range without dipping into the slop from 3.0-3.5, but I
> > bet it's a challenge.
> If your detector was sensitive to the band from 3 to 4 microns, and
> there is no radiation to see at 3 to 3.5 microns, it doesn't really
> hurt you any, does it?
That's true *unless* the radiation is backscattered by water vapor.
Then you get haze and blurring of the objects you want to view. That's a
real problem in blue bands (sub-500 nm). I don't know if it's a factor
in the 3-3.5 micron range.
> Smoke is an interesting problem - if it can absorb at 3.5-4 microns,
> it can also radiate in the same band. If it cools off by mixing with
> the air it could form an insulating blanket around the flame and
> prevent its radiation from getting out, but if it forms a hot plume it
> should also be visible in the mid infrared. I don't know which of
> these is more typical.
From experience, I'd say that absorption dominates. Smoke is seldom
hot enough to be visible in the SWIR, but it will obscure hot points on
the ground in the NIR and visible bands.
Chris Thompson
Derek Lyons <fair...@gmail.com> wrote:
>"rick++" <ric...@hotmail.com> wrote:
>
>>I can see people directly in Google Satellite pictures (Digital
>>Globe). Thats not top of the line technology for the 20th century
>>or what will possible in future decades.
>
>The high resolution photos in GE and GM where you can see people
>aren't satellite pictures - but are ariel shots.
This was Ariel attempting to beat Puck's 40 minute record, was it?
--
Chris Thompson
Email: cet1 [at] cam.ac.uk
Mark Borgerson
8g2000hse.googlegroups.com>, johnma...@yahoo.com says...
> On Jul 3, 10:17 am, Space Cadet <kaw...@gmail.com> wrote:
> > Given a fully human habitable Earth like world
> > An a human population of 100,000 - 1,000,000
> > Living in small hunter/gather groups or small agraian groups, spread
> > out over the whole planet.
> >
> > If you were in a spacecraft in Low Planetary Orbit
> > With a full suite of remote sensing gear that is only slightly more
> > advance that what is commerically available, ie Not military grade
> > hardware.
> >
> > looking for them and they don't know you are in orbit and are not
> > trying to hide themselves
> >
> > And all you are looking for is a good spot to set down your
> > colony(ies)/settlement(s)
> >
> > How easy or hard would it be to detect the presence of hunter/gather
> > groups or small family farms?
>
> technological humans and non-sapient animals of similar body size from
> orbit. If they are at the level of building houses and warming them by
> fires, these could be detected from orbit, but might perhaps be
> misinterpreted if the observer isn't expecting and looking for them.
>
> a good spot to set down your colony(ies)/settlement(s)" would do a
> fair amount of surface-level survey, in which framers or even hunter-
> gatherers would be quite likely to be noticed.
>
> (You don't make it clear, are the observers assumed to be a different
> species then the observed low-tech sapients, or are we to assume a
> "lost colony" or something of the sort?)
> >
> > Would thermal imaging systems be able to tell the difference from
> > human body heat and that of a large native mammal?
>
> know what they look like, visual imagery from orbit could possibly
> tell the difference, but if you don't know what the various animals
> look like, such observation is not very helpful.
>
> >How big would a
> > camp/cook fire have to be to be detectible from orbit?
>
> more important is how good the analysis programs are. How well can a
> campfire be distinguished from random hot spots (stone outcrops heated
> in the sun and slow to cool, for example) or lightning-set fires. How
> well do the explorers know the detailed environment and what is
> plausible there?
>
> > How large would a family garden or cultivated field have to be to be
>
> There are lots of local, small micro environments in many non-
> cultivated settings. For the field to be distinguishable is one thing,
> for it to be recognized for what it is, the product of sapient
> technology is quite another.
Software that looks for straight line boundaries would be a good start.
>
> >
> > 2)You suspect they are people down on the planet and they don't know
> > you are there and you are actively looking for them, how hard or easy
> > would that be?
>
> Depends on their tech level, the quality of the sensors, and the
> amount of effort you take, and how well you know what to expect. If
> they are farmers, and you are looking for farmers, you will probably
> find them. Hunter-gatherers, particularly ones that don't use fire,
> will be hard to find unless you know exactly what they look like
> compared to other animals of similar size.
> >
> > 3)Same as 1, but they somehow know that you are up there, they see a
> > new 'star' in the sky and reconize it for what it is a ship in orbit
> > and take efforts to conceal themselves, how hard or easy to do that?
> >
> If they had legends/memories of high-tech, they might be able to
> conceal themselves fairly well, depending on their lifestyle. If they
> can stay in caves during daylight, and not make fire outside at night,
> they would be quite hard to find for orbit, IMO. But how would they
> figure out that that is the way to hide without some fairly accurate
> knowledge of tech and what it can and cannot do?
>
>
> What is the point or context of these various speculations?
Mark Borgerson
Eivind
> I'd hazard a guess that more than half of the "bad resolution" areas are
> political at the source
Nah. They're just bad resolution because whomever owns the
image-repository ain't got highres photos of the area in question.
Oftentimes different map-sources have different foggy areas, which sorta
demonstrates the point.
There -ARE- areas that are intentionally fogged, but they make out a
minute fraction of any country. Military bases and thelike.
> - Much of my hometown, for instance, is (quite obviously deliberately)
> "fogged out" on Google Earth.
> Why would a city be fogged out like that? Hmmm... Could it have
> something to do with the fact that said city is the home port of a piece
> of pretty high-end hardware that would make a decent target should one
> want to hamstring a *MAJOR* shipping channel?
That's not it. It's pretty hard to see how fogging the home-port of some
icebreaker does anything significant for the security of the same ship.
Eivind
Leszek Karlik
[...]
>> Why would a city be fogged out like that? Hmmm... Could it have
>> something to do with the fact that said city is the home port of a
>> piece of pretty high-end hardware that would make a decent target
>> should one want to hamstring a *MAJOR* shipping channel?
>
> That's not it. It's pretty hard to see how fogging the home-port of some
> icebreaker does anything significant for the security of the same ship.
It's the War on Movie-Plot Terrorism.
(Much easier and cheaper than the war on real terrorism. And more
reassuring, everybody knows how Movie-Plot Terrorism looks like,
they've seen it in the movies. And on 24. So, we have to lock up
all people who make photographs. And make Jack Bauer torture them,
just in case. :-)))
> Eivind
Leslie
--
Leszek 'Leslie' Karlik
Christopher Henrich
Eivind <eivin...@gmail.com> wrote:
When I went to look at the situation which Don Bruder described, I saw
that Google Earth had a rectangular strip of high-resolution map,
stretching from Cheboygan down through central Michigan to near
Crawford, Mich. It really looks to me as though the project of supplying
high-resolution maps of the whole world, or even of the USA, is ongoing
and will be ongoing for quite a while.
--
Christopher J. Henrich
chen...@monmouth.com
htp://www.mathinteract.com
Michael Ash
> That's not it. It's pretty hard to see how fogging the home-port of some
> icebreaker does anything significant for the security of the same ship.
It's pretty hard to see how blurring the roof of the White House and US
Capitol does anything significant for the security of those buildings,
when anyone who feels like it can go up the Old Post Office Tower and look
at the top of both buildings with their own two eyes. Yet they were both
blurred for a while. It seems that they've come to their senses now,
fortunately.
(As an aside, if any of you visit DC, that tower is one of the best kept
tourist secrets. It's not all that busy and it's completely free. Sure
beats showing up at 4AM to get tickets for the Washington Monument!)
--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon
John Schilling
>In rec.arts.sf.science Eivind <eivin...@gmail.com> wrote:
>> That's not it. It's pretty hard to see how fogging the home-port of some
>> icebreaker does anything significant for the security of the same ship.
>It's pretty hard to see how blurring the roof of the White House and US
>Capitol does anything significant for the security of those buildings,
>when anyone who feels like it can go up the Old Post Office Tower and look
>at the top of both buildings with their own two eyes. Yet they were both
>blurred for a while. It seems that they've come to their senses now,
>fortunately.
Or, they had a different sensible plan. If the best place to get decent
targeting data on the White House and Capitol is from the Old Post Office
Tower, and the Old Post Office Tower is a best-kept tourist secret, then
there would be an enhanced terrorist:tourist ratio at the Tower. Match
the security camera footage there against your existing watch list, and
add the data to the profile.
This actually is a standard security tactic, generally speaking. For any
high-value target, assume that someone has gone and figured out where to
best conduct pre-attack surveillance on that target, and are themselves
surveiling *those* places to see who is hanging around taking pictures.
And it does argue in favor of making sure the best place to conduct
pre-attack surveillance, is not "any computer connected to the internet
anywhere".
>(As an aside, if any of you visit DC, that tower is one of the best kept
>tourist secrets. It's not all that busy and it's completely free. Sure
>beats showing up at 4AM to get tickets for the Washington Monument!)
It also argues against encouraging hordes of tourists to hang around the
surveilance areas. Oh, well...
--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
*John.Sc...@alumni.usc.edu * for success" *
*661-951-9107 or 661-275-6795 * -58th Rule of Acquisition *
Michael Ash
> On Tue, 22 Jul 2008 09:15:48 -0500, Michael Ash <mi...@mikeash.com> wrote:
>
>>In rec.arts.sf.science Eivind <eivin...@gmail.com> wrote:
>>> That's not it. It's pretty hard to see how fogging the home-port of some
>>> icebreaker does anything significant for the security of the same ship.
>
>>It's pretty hard to see how blurring the roof of the White House and US
>>Capitol does anything significant for the security of those buildings,
>>when anyone who feels like it can go up the Old Post Office Tower and look
>>at the top of both buildings with their own two eyes. Yet they were both
>>blurred for a while. It seems that they've come to their senses now,
>>fortunately.
>
> Or, they had a different sensible plan. If the best place to get decent
> targeting data on the White House and Capitol is from the Old Post Office
> Tower, and the Old Post Office Tower is a best-kept tourist secret, then
> there would be an enhanced terrorist:tourist ratio at the Tower. Match
> the security camera footage there against your existing watch list, and
> add the data to the profile.
>
> This actually is a standard security tactic, generally speaking. For any
> high-value target, assume that someone has gone and figured out where to
> best conduct pre-attack surveillance on that target, and are themselves
> surveiling *those* places to see who is hanging around taking pictures.
>
> And it does argue in favor of making sure the best place to conduct
> pre-attack surveillance, is not "any computer connected to the internet
> anywhere".
I think you are giving these people waaaayyyyyyyy too much credit. Occam's
razor says that the blurring of these buildings was because of
institutional fear and CYA, not security masterminds figuring out
extremely clever ways to gather info on potential terrorists.
>>(As an aside, if any of you visit DC, that tower is one of the best kept
>>tourist secrets. It's not all that busy and it's completely free. Sure
>>beats showing up at 4AM to get tickets for the Washington Monument!)
>
> It also argues against encouraging hordes of tourists to hang around the
> surveilance areas. Oh, well...
If hordes of tourists started hanging around it then it would stop being
so interesting. The only advantage it has over the better-known Washington
Monument is that it's quiet. Oh, and that there's a mall at the bottom, so
you can buy ice cream after you're through.
John Schilling
How so? Occam says nothing about stupidity being a more plausible
assumption than smartness, just that you need to minimize assumptions.
If the stupid-person antiterrorist playbook has an entry for "classify
everything, in the name of paranoia!", and the smart-person antiterrorist
playbook has an entry for "make preattack surveilance difficult and/or
dangerous, then watch to see who's still doing it", then both hypotheses
require one assumption - that these people are working from a particular
playbook.
Michael Ash
There are two ways to arrive at my conclusion, if you back up and start a
little earlier.
First, the human-hating way. Most people are stupid. Any given person is
much more likely to be stupid than to be smart. This is amplified in a
situation like this where you need several people coming to some sort of
agreement. When both smart and stupid explain an action, stupid is the
simpler assumption. This is kind of a more general form of Hanlon's razor.
Second, the government-hating way. Government agencies are, in general,
stupid. The ones that aren't obviously stupid are the ones that are too
secretive to be obviously anything. You can suppose that the secretive
ones are somehow special and avoid the pervasive stupidness that infects
government. (And humanity.) Or you can simply suppose that these agencies
are like all the others, just more secretive. Again, the latter is a
vastly simpler assumption.
Yeah, you can call it "one assumption" if you want, and just count them,
and it makes no sense. It's "one assumption" that JFK was killed by a
conspiracy between the CIA, the mafia, Castro, LBJ, the Teamsters, and the
Freemasons, and but Occam's razor still favors the explanation that it was
Lee Oswald on his own. Occam's razor says to look for simplicity. Stupid
people doing stupid things is simple. Smart people doing smart things is
not.
Derek Lyons
>Occam's razor says to look for simplicity. Stupid
>people doing stupid things is simple. Smart people doing smart things is
>not.
ROTFL.
John Schilling
Right. So if the same conclusion can be reached by assuming stupidity
or assuming smartness, Occam says nothing at all useful.
>> If the stupid-person antiterrorist playbook has an entry for "classify
>> everything, in the name of paranoia!", and the smart-person antiterrorist
>> playbook has an entry for "make preattack surveilance difficult and/or
>> dangerous, then watch to see who's still doing it", then both hypotheses
>> require one assumption - that these people are working from a particular
>> playbook.
>There are two ways to arrive at my conclusion, if you back up and start a
>little earlier.
>First, the human-hating way. Most people are stupid. Any given person is
>much more likely to be stupid than to be smart. This is amplified in a
>situation like this where you need several people coming to some sort of
>agreement. When both smart and stupid explain an action, stupid is the
>simpler assumption. This is kind of a more general form of Hanlon's razor.
A: This is a science-fiction newsgroup; you can call it Heinlein's razor.
B: Most humans are not stupid. Most humans, at least, are smart enough
to do their jobs more or less by the book. And humans in the security
business, are demonstrably smart enough to have written their books to
include countersurveillance as a basic technique
B': Most governments, and government agencies, are not stupid either.
C: If your argument is in fact, "Occam's razor combined with an assumption
of human stupidity indicates [X]", it is improper for you to state that
"Occam's razor indicates [X]".
D: If [X] is, "a group of humans have behaved stupidly", then what you are
really arguing is, "Occam's razor combined with an assumption of human
stupidity, indicates that a group of humans have behaved stupidly".
I am unimpressed by your circular logic, or by your attempt to hide it
under Occam's cloak. The only stupid human here, is the one who assumed
stupidity in an attempt to prove stupidity.
--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
*John.S...@alumni.usc.edu * for success" *
*661-718-0955 or 661-275-6795 * -58th Rule of Acquisition *
Michael Ash
I hope you realize that you are replying to *yourself* here. It seems
awfully smug to start such a self-reply with "Right."
>>> If the stupid-person antiterrorist playbook has an entry for "classify
>>> everything, in the name of paranoia!", and the smart-person antiterrorist
>>> playbook has an entry for "make preattack surveilance difficult and/or
>>> dangerous, then watch to see who's still doing it", then both hypotheses
>>> require one assumption - that these people are working from a particular
>>> playbook.
>
>>There are two ways to arrive at my conclusion, if you back up and start a
>>little earlier.
>
>>First, the human-hating way. Most people are stupid. Any given person is
>>much more likely to be stupid than to be smart. This is amplified in a
>>situation like this where you need several people coming to some sort of
>>agreement. When both smart and stupid explain an action, stupid is the
>>simpler assumption. This is kind of a more general form of Hanlon's razor.
>
> A: This is a science-fiction newsgroup; you can call it Heinlein's razor.
I could, but it is not generally known that way, so why would I?
> B: Most humans are not stupid. Most humans, at least, are smart enough
> to do their jobs more or less by the book. And humans in the security
> business, are demonstrably smart enough to have written their books to
> include countersurveillance as a basic technique
I must disagree. Most humans *are* stupid, in general. *Some* humans in
the security business are smart enough to have written their books this
way. Some are dumb enough to have written other books, and most are not
smart enough to have written any books at all.
> B': Most governments, and government agencies, are not stupid either.
I'm gonna need some evidence for this claim.
> C: If your argument is in fact, "Occam's razor combined with an assumption
> of human stupidity indicates [X]", it is improper for you to state that
> "Occam's razor indicates [X]".
Human stupidity is not an assumption, but rather a fact.
Half the people on the planet are of below-average intelligence. Even most
of the above-average people are not terribly impressive.
> D: If [X] is, "a group of humans have behaved stupidly", then what you are
> really arguing is, "Occam's razor combined with an assumption of human
> stupidity, indicates that a group of humans have behaved stupidly".
Combined with the fact that humans are stupid in general, particularly in
aggregate, and that groups of humans which behave in a smart manner are
exceedingly rare, yes. I'm just playing the numbers here.
> I am unimpressed by your circular logic, or by your attempt to hide it
> under Occam's cloak. The only stupid human here, is the one who assumed
> stupidity in an attempt to prove stupidity.
There's nothing circular here. Human stupidity is like assuming that most
people are under 6 feet 6 inches tall. If your facts are equally explained
by people of abnormal height and people of normal height, pick the people
with normal height.
In particular, the action of the stupid people is exceedingly simple. You
put in a request, you block the pictures, end of story. It's a standard
knee-jerk reaction, which the modern security business is full of.
(Example: any TSA operation in the entire country.) The action of the
smart people is exceedingly complex. It is vastly simpler to assume stupid
people doing simple things than to assume a whole bunch of smart people
concentrating on this one thing doing a whole bunch of complex things
about it.