What could be detected from orbit?

[Golan2072]

Assume a Type-S Scout/Courier reaches a planet "where no man has gone before", that is previously unexplored by the Imperium (or whatever polity have launched the Type-S). The way I see it, a Type-S is usually TL11 (minimal TL for Jump-2, and you'd like to keep it as low-tech as possible to allow repairs and/or refits on frontier starports), with rudimentary sensors (represented by the Model/1bis computer).

1) How long do you think it will take the Type-S to generate a planetary map (mid-resolution, or, in game terms, the typical Traveller planetary hex-map)? Would it be possible to detect all geographical features from orbit (I think so)?

2) Would it be possible to detect the presence of life from orbit? If so, how much information could be gathered about these lifeforms without landing?

3) How easy would it be to detect the presence of a civilization? I think that, generally speaking, TL5+ civilizations are easy to detect once the invent the radio and use it widely, as well as due to the impact of any industrial civilization on a world (strip-mining, IR emissions of heavy industry and so on.

4) What kinds of sophont-made structures (mines, roads, railroads/monorail, cities, towns, agricultural terrains, military bases/forts) could be detected from orbit?

 

[RandyT0001]

Originally posted by Employee 2-4601:
Assume a Type-S Scout/Courier reaches a planet "where no man has gone before", that is previously unexplored by the Imperium (or whatever polity have launched the Type-S). The way I see it, a Type-S is usually TL11 (minimal TL for Jump-2, and you'd like to keep it as low-tech as possible to allow repairs and/or refits on frontier starports), with rudimentary sensors (represented by the Model/1bis computer).

1) How long do you think it will take the Type-S to generate a planetary map (mid-resolution, or, in game terms, the typical Traveller planetary hex-map)? Would it be possible to detect all geographical features from orbit (I think so)?

I'd call the typical Traveller planetary hex map low resolution myself. I think one of the adventures or double adventures says that two orbits will allow one to compile a map similar to the hex maps. Personally I think you would need more orbits to get a more detailed map where, say, 10m contours could be mapped out. I think one would use the radio spectrum (radar) of the EM range to do this since some wavelengths are not absorbed by atmospheres (NASA used radar to map out Venus' surface features this way).

2) Would it be possible to detect the presence of life from orbit? If so, how much information could be gathered about these lifeforms without landing?

With the right sensors, yes, you could detect life from orbit. There are IR satellites today that can let farmers know how well their fields are doing in terms of plant growth, etc. Different crops have different IR absorbtions. But this was done by testing crops on the surface first to find the absorbtion lines(?) and then the sensors were built and placed in orbit to survey the fields. I guess one could compare the unknown planet's plant life to known plants of other worlds to get some types of information.

3) How easy would it be to detect the presence of a civilization? I think that, generally speaking, TL5+ civilizations are easy to detect once the invent the radio and use it widely, as well as due to the impact of any industrial civilization on a world (strip-mining, IR emissions of heavy industry and so on.

4) What kinds of sophont-made structures (mines, roads, railroads/monorail, cities, towns, agricultural terrains, military bases/forts) could be detected from orbit?

If your sensors have a resolution on the order of one meter then you should be able to see surface buildings and vehicles regardless of native TL. Cloud cover could obscure some of it to some sensors types (visible for example).

IMO

 

[Andrew Boulton]

Say Size*1.5hrs to generate a 1m resolution map from high orbit. Significant life and civilisation will be obvious. A full survey could easily take a week or more.

 

[Golan2072]

Originally posted by Randy Tyler:
With the right sensors, yes, you could detect life from orbit. There are IR satellites today that can let farmers know how well their fields are doing in terms of plant growth, etc. Different crops have different IR absorbtions. But this was done by testing crops on the surface first to find the absorbtion lines(?) and then the sensors were built and placed in orbit to survey the fields. I guess one could compare the unknown planet's plant life to known plants of other worlds to get some types of information.

Hmmm... So this would probably boil down to how efficient your analysis program is - a planet is ALOT of surface to survey, especially with 1m resolution or better, and you'll probably want a computer program which will be able to identify probable lifeforms and probable artificial features out of the massive amount of visible light, radar and IR footafge obtained by several orbits. High enough resolution combined with a high-tech computer (and high-tech analysis software, ofcourse) might even give you an estimate of a world's TL (from analysing structures, vehicles etc from orbit) and population.

Your answers so far ended up far more impressive than I've thought before - thank you for enlighting me - so lets put the question otherwise: what CAN'T you do from orbit, survey-wise?

 

[Black Globe Generator]

I don't have my reprints handy, but if you have Book 4: Mercenary, look up the Map Box in the Equipment section - the description includes blank map chips and says how many orbits are required by a starship to create a new map for use with the Map Box.

Grand Census covers all of the rest of this in detail - I don't know if I'll have time today, but if I can I'll dig it out and summarize it for you.

 

[RandyT0001]

Originally posted by Employee 2-4601:
Your answers so far ended up far more impressive than I've thought before - thank you for enlighting me

What? You haven't considered my answers and comments to previous questions and topics to be impressive(ly analytical) before? Shame on you Omer (Corrected a misspelled name. SORRY!! ). Just take at look at this!!

so lets put the question otherwise: what CAN'T you do from orbit, survey-wise?

Well, I don't think you'll be able to get alot of detailed, high resolution information about things underground. Some radars can penetrate some soil types but once you get to rock you're left with seismic recordings to gain information about subsurfaces and that would entail some small seismic probes to land on the world. Then you have to artifically make the seismic waves (might be years before a naturally occuring quake occurs) for the instruments to read. This is from what I understand of present technology and it's limits. Who can predict what higher TL's could do in the realm of subsurface mapping.
IMO

 

[Golan2072]

Originally posted by Randy Tyler:
What? You haven't considered my answers and comments to previous questions and topics to be impressive(ly analytical) before? Shame on you Omar. Just take at look at this!!

What I meant was that the actual RL orbital capabilities are more impressed than I've thought before. You answers are as impressive as always

Oh, and it's Omer, not Omar

 

[Chaos]

Originally posted by Employee 2-4601:
</font><blockquote>quote:</font><hr />Originally posted by Randy Tyler:
With the right sensors, yes, you could detect life from orbit. There are IR satellites today that can let farmers know how well their fields are doing in terms of plant growth, etc. Different crops have different IR absorbtions. But this was done by testing crops on the surface first to find the absorbtion lines(?) and then the sensors were built and placed in orbit to survey the fields. I guess one could compare the unknown planet's plant life to known plants of other worlds to get some types of information.

Hmmm... So this would probably boil down to how efficient your analysis program is - a planet is ALOT of surface to survey, especially with 1m resolution or better, and you'll probably want a computer program which will be able to identify probable lifeforms and probable artificial features out of the massive amount of visible light, radar and IR footafge obtained by several orbits. High enough resolution combined with a high-tech computer (and high-tech analysis software, ofcourse) might even give you an estimate of a world's TL (from analysing structures, vehicles etc from orbit) and population.

Your answers so far ended up far more impressive than I've thought before - thank you for enlighting me - so lets put the question otherwise: what CAN'T you do from orbit, survey-wise? </font>[/QUOTE]Searching for civilizations is easier than that. You probably concentrate on the most inviting regions.

On Earth, the most ancient civilizations (that I´m aware of) started on the banks of a major river - the Nile, the Jangzte, the Euphrates and Tigris.
If there is a civilization, you will probably find it near a river; its benefits for trade, transport and irrigation are hard to beat.

 

[Bob Weaver]

Originally posted by Black Globe Generator:
I don't have my reprints handy, but if you have Book 4: Mercenary, look up the Map Box in the Equipment section - the description includes blank map chips and says how many orbits are required by a starship to create a new map for use with the Map Box.

Grand Census covers all of the rest of this in detail - I don't know if I'll have time today, but if I can I'll dig it out and summarize it for you.

Book 4 says two orbital sweeps will provide the necessary images to build a map. Since the map box itself is TL 9, I assume that the ship doing the imaging would need to be at least TL 9 as well. Not too difficult to provide, if the trusty old Type S is TL 11.

Cheers,

Bob W

 

[TheEngineer]

Originally posted by Employee 2-4601:

1) How long do you think it will take the Type-S to generate a planetary map (mid-resolution, or, in game terms, the typical Traveller planetary hex-map)? Would it be possible to detect all geographical features from orbit (I think so)?

Well, we already have the two sweeps time.
With TL-11 equipment, respectively Active/Passive EMS and a densiometers, you might get a really comprehensive picture of the planet, especially if the 1bis computer as a GeoSim plugin installed

2) Would it be possible to detect the presence of life from orbit? If so, how much information could be gathered about these lifeforms without landing?

Analysing the pure geoplogical and atmospherical data would allow to find traces, which are caused by some kind of biological life. Thats maybe more difficult for underground life.

3) How easy would it be to detect the presence of a civilization? I think that, generally speaking, TL5+ civilizations are easy to detect once the invent the radio and use it widely, as well as due to the impact of any industrial civilization on a world (strip-mining, IR emissions of heavy industry and so on.

Civilizations as we know them usually have modified their environment in a very significant way, so at even lower TL their "modifier" nature would be visible far away

Everything not shaped by "dead" nature could be recognized (structures, modified environment) perhaps even if its located underground.
But that perhaps not a "must" and maybe there are civilisations, who are able to adapt themself better than we do, so that they do not need to modify their environment to get along.
What is a civilisation ?

4) What kinds of sophont-made structures (mines, roads, railroads/monorail, cities, towns, agricultural terrains, military bases/forts) could be detected from orbit?

With a high penetration densiometer and the other TL-11 sensors I would assume everything.

TE

 

[Icosahedron]

The world-tamers handbook gives details on orbital surveys, but for TL8 real life, take a look at Google Earth, which can pick up individual vehicles, then remember this is only what is released for the public and for free. I've heard some military optical satellites can read a car registration plate, and recognise an individual person. Maybe that's BS, but at TL11+, who knows?
If densitometers exist IYTU, I'd have them go down a couple of hundred metres, but remember a deep meson site is supposed to be undetectable, so there must be a limit to sensor penetration depth, and any military facility would have bunkers purposefully constructed below this depth.

I use some house rules for survey, the basics of which are:
At a range of (computer number) parsecs, a ship can detect all stellar data.
At a range of 1 parsec (adjoining hex) a ship can determine the presence and orbit of gas giants.
At a range of 0.5pc (same hex) a ship can detect number, orbit and size of all major system bodies.
At a range within Orbit 15 (2500AU) a ship can detect most features from LBB6 except population and its derivatives, but including any EM signals.
From Stationary Orbit, a ship can determine precise atmospheric composition, distribution of surface temperature & weather, location of EM sources, and village-size light sources on the night side.
From Close Orbit (skimming atmosphere) most things can be detected, but roll computer size on 2D6 to detect herds or vehicles.
From an airborne atmospheric survey, the agricultural capacity of land can be checked but roll computer size to detect/track individual life forms.
A ground survey is needed to check for raw materials, population, flora, fauna, etc.

Remember that, by definition, orbiting requires the ship to circle the planet, so detection of any one part will not be continuous.

 

[TheEngineer]

Hi !

Ico is quite right with the densiometer penetration range.
In MT a TL15 densiometer could penetrate up to 1000 m, but thats it, so the meson sites are safe

TE

 

[Plankowner]

For long range Detection of system features, the Alien Module on the Aslan gives ranges for detecting GG and Systems.

I THINK it was 6 parsecs for GG and 1 parsec for major system features after 1 week's study.

I'm sure Sigg can tell us the details pretty quickly...

 

[Plankowner]

For detecting life, it is actually pretty simple for life similar to ours...

The presence of oxygen in the atmosphere means life. In traveller terms ATM 2-9 have life on them. Oxygen reacts too quickly with other things to stay in an atmosphere for very long. If you have oxygen, you have life.

Now, other types of life that do not use oxygen might be harder to detect, and individual types of life would be hard to detect.

Didn't the Galileo space probe detect "life" on Earth when it passed by on it's way to Jupiter? It detected oxygen, water etc, so they confirmed that there was life on Earth, they did not detect anything that would have confirmed intelligence though (smart-ass comment not made, but thought!).

Humans from Low Orbit can see a couple of man-made features in daylight and can easily see the city lights at night. I think the Pyramids and the Great Wall are visible from space, but I'm not sure if that is just a myth...

 

[Andrew Boulton]

The GWoC can't (easily) be seen from orbit, but many other man-made things ca.

http://www.snopes.com/science/greatwal.htm

 

[aramis]

And, according to same source, it's readily DETECTED from orbit with radar.

Detectability and Visibility are NOT synonyms. Visibility is a narrow subset of detectability.

And yes, Galileo did "detect" signs of life. It did detect indicators of intelligence, or at least technology; specifically it detected city lights. Not conclusive, but fairly close. (Discovery Channel)

With vision aids, Geosynch is capable of detailed photography to about 1m resolution; LEO can be gotten down to several cm resolution, but that hits atmospheric limitations.

 

[Gaming Glen]

Also consider that in Supplement 7 Traders and Gunboats it is mentioned that the rear cargo area of the Scout/Courier carries optional equipment, such as extra sensors (and extra computing power I presume) for scouting missions or extra communications equipment for performing courier missions.

What is missing is exactly what the basic sensors can or cannot do, besides detecting other ships, and what can be added or plugged in.

I miss MegaTraveller's more detailed sensor equipment lists for space ships.