Kraven Kor Posted August 3, 2009 Report Share Posted August 3, 2009 In Star Trek, the advanced sensors of futuristic space craft could practically detect anything. But realistically, what are the options for "sensors" - shipboard or hand held? Where can I get a primer on (somewhat) realistic "sensor" technologies? What are my players going to be able to tell about that lush green planetoid they see out their viewports before they establish orbit and send down a dropship? Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" "It's . . . it's green!" Quote Link to comment Share on other sites More sharing options...
ghostwolf Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" I think they would be able to detect weather patterns, get a decent topographical map, and perhaps do spectroanalysis to determine the atmosphere composition from a distance. If they have good telescopic sensors, they might be able to do an birds-eye view of terrain areas and use their computer to pattern match for lifeforms (detect movement, construction etc.) Further studies could be conducted with unmanned probes. They could probably also extrapolate the planets composition from it's magnetic field. Quote Link to comment Share on other sites More sharing options...
Ian Mackinder Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" Being able to plot its orbit, and then compare that against the system's primaries, should provide a means of corroborating the world's density. Infrared should provide details about surface temperatures and, if sensitive enough, about things like weather patterns, ocean currents and tectonic / volcanic activity. UV has been used to highlight differances in plant growth pattterns, or for "hidden details". Various recent satellites have VERY precise radar mapping systems that enable them to survey the planetary surface in considerable detail. Been a few Earth satellites that have used this technology to find ancient cities hidden under jungle canopies or desert sands. A couple of probes to Mars have also used this to map out Mars in considerable detail. The process takes a while because the probe is basically directing a radar beam more or less straight down, and may need several passes to map out any region. Simply plotting the paths of satellites around the world can provide data. Refer "mascons" - http://en.wikipedia.org/wiki/Mascon Quote Link to comment Share on other sites More sharing options...
sinanju Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" In Star Trek, the advanced sensors of futuristic space craft could practically detect anything. But realistically, what are the options for "sensors" - shipboard or hand held? Where can I get a primer on (somewhat) realistic "sensor" technologies? What are my players going to be able to tell about that lush green planetoid they see out their viewports before they establish orbit and send down a dropship? I know where you're coming from. I hate the Star Trek version of sensors with a passion--especially "life sensors". (And never mind that they've more than once established that the Enterprise could detect events in distant star systems in real time....) The options for realistic sensors depends on the general tech level (and type of tech) your game includes. Quote Link to comment Share on other sites More sharing options...
austenandrews Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" Seems to me it's as much a matter of knowledge as data collection. You can get lots of data from a telescope, but there's a big difference between just "seeing what's down there" and having a computer that can tell you if a certain distribution of elements across a certain terrain is the signature for particular life forms. Quote Link to comment Share on other sites More sharing options...
ajackson Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" If you want realistic, a good place to start is what current satellites can do. This looks like a good place to jump off from. Quote Link to comment Share on other sites More sharing options...
Kraven Kor Posted August 4, 2009 Author Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" The options for realistic sensors depends on the general tech level (and type of tech) your game includes. I want to stick to as much hard sci-fi as I can - tech extrapolated from current bleeding edge technologies, etc. So no FTL communication or sensors, really - ships can go FTL using a drive that essentially creates a shortcut in space-time but still take days to weeks to travel to another system. There are comm ships that run messages back and forth constantly, generally automated ships, but again you are talking days to weeks to get a message sent or receive a response. All traditional stuff - radar, radio, laser communications, etc. are limited by speed of light just as they are today. I intend to hit the players constantly with issues where they need to make a decision and cannot check back with command since that would take too long. I have a lot of advanced tech and don't mind handwavium where necessary, but wish to avoid it as much as possible and have some neat science behind the campaign. Quote Link to comment Share on other sites More sharing options...
DrTemp Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" Analyzing the light hat is reflected by the atmosphere might allow to identify its composition. This could possibly also work for foreign starships that have windows, I don't know. Quote Link to comment Share on other sites More sharing options...
Sundog Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" If you have sufficiently sensitive spectrographic systems, you don't need windows. Just determine what gasses are leaking through their hull. Probably won't tell you the percentages, but should give you a composition. Quote Link to comment Share on other sites More sharing options...
Clonus Posted August 4, 2009 Report Share Posted August 4, 2009 Re: (Somewhat) realistic "Sensors" Well let's see now. They can, first of all identify large power generators on the surface and any installation that uses a lot of power. They can get a detailed breakdown of the inorganic composition of the atmosphere. They can tell you whether a planet has large animals from their heat output and take a fairly accurate guess how big they'll be (but not how intelligent or dangerous they might be). They can give an accurate three-day weather forecast for any part of the planet. (Don't laugh, it's important if you want to land). They can identify agricultural fields through optical image processing. They can tell you what the level of background radiation will be. They can detect radio transmissions, anything from spark gap transmitters to cellphone carriers. They can give you a fairly detailed topographic map of any place you want to land. They can detect concentrations of ferrous or very dense minerals from the effect on magnetism or gravity. They can identify ocean currents. They can calculate tidal cycles. Quote Link to comment Share on other sites More sharing options...
Ian Mackinder Posted August 5, 2009 Report Share Posted August 5, 2009 Re: (Somewhat) realistic "Sensors" They can tell you whether a planet has large animals from their heat output and take a fairly accurate guess how big they'll be (but not how intelligent or dangerous they might be). . Add to that, "...large GROUPS of animals...". Individual members might be not be all that large, but get a big bunch of them together in one area and they might be even more obvious than a lesser number of larger beasts. Quote Link to comment Share on other sites More sharing options...
Ian Mackinder Posted August 5, 2009 Report Share Posted August 5, 2009 Re: (Somewhat) realistic "Sensors" Image analysis via computer is now sophisticated enough that systems distinguish between images of cancerous and non-cancerous cells with greater speed and accuracy than a trained human. Given a few decades (minumum) of development, I can easily see something like this being used to provide a pretty decent analysis of a plamet from far orbit or even further away. Especially if it involves integrating data from various different sources (and comparisons with other worlds). A few other thoughts ... Albedo (the proportion of heat / light reflected back into space) would be a factor in determining a world's climate. Differential analysis of planetary temperatues. In plain English, reading the temperature differances between various regions - tropical / temperate / polar, or even just dayside / nightside - will also go towards helping to determine climate and weather patterns. Geological featues visually distinguishable from orbit will say a lot. Mountain ranges, volcanoes and island chains will aid in figuring out plate tectonics (if any). Certain landforms will be helpful as regards understanding waterflow - tidelines, floodplains, scablands, canyons, etc.. It also occurs to me that certain analytical tools used in the Gulf War and later might have their uses here. Fractal image analysis has been used to find manmade features where none are apparent - "lost" cities or Saddam Hussein's secret bunkers, for instance. One could apply this to planetary surveys - if features like the weather patterns or the plate tectonics of an alien world are found to be "hinky", this could be indicative of artificial manipulation. On watching civilizations from afar, there is one approach that has been used very effectively against terrorists in Iraq and Afghanistan, and could have uses in an interstellar milieu. Very simply, one videos an area for a length of time, then does a series of fast forwards and fast reverses to see what the traffic is doing. The analysis of this data has become a lot more sophisticated with time, but the principle remains. For watching an alien settlement, this method could be very helpful in "big picture" analysis. Eg, all the beasts of burden are loaded with stuff HERE and then go HERE, where they are unloaded; the guys in the funny hats hang around HERE, but always go HERE at sunset; everybody goes HERE and HERE for water, but never HERE; and so on. Quote Link to comment Share on other sites More sharing options...
Kraven Kor Posted August 5, 2009 Author Report Share Posted August 5, 2009 Re: (Somewhat) realistic "Sensors" What about realistic personal sensory devices? Obviously Nightvision, UV Vision, HRRP and such in their PDA/HUD. Motion Detectors like in Aliens (I'm building them as Detect: Motion, unless someone has a better idea.) EM Gauges which can detect background radiation for safety reasons, as well as detecting the presence of power sources or encrypted radio signals and such - build as "Detect: EM" I guess? Quote Link to comment Share on other sites More sharing options...
Yansuf Posted August 5, 2009 Report Share Posted August 5, 2009 Re: (Somewhat) realistic "Sensors" What about realistic personal sensory devices? Obviously Nightvision, UV Vision, HRRP and such in their PDA/HUD. Motion Detectors like in Aliens (I'm building them as Detect: Motion, unless someone has a better idea.) EM Gauges which can detect background radiation for safety reasons, as well as detecting the presence of power sources or encrypted radio signals and such - build as "Detect: EM" I guess? UV vision is of very little use; if there is enough UV to see by there is enough visible and/or IR to see by, except in an artificial environment. Of course it can be used with a UV searchlight, but that could cause sunburn! As I recall, the motion detectors in ALIENS were not reality based, but it has been many years. Current motion detectors use radar or sonar. What did ALIENS use? If your EM means electro-magnetic, that is realistic. For life sensors, check out the following: http://marsprogram.jpl.nasa.gov/technology/lifedetectors/ I recall reading about sensors that can detect mammals by the weak EM fields of their bodies/nervous systems several years ago. The John Clancy novel Rainbow 6 had them used. (I had read about them on the internet prior to the publication of the novel.) But I didn't find anything today from a quick net search. Quote Link to comment Share on other sites More sharing options...
austenandrews Posted August 5, 2009 Report Share Posted August 5, 2009 Re: (Somewhat) realistic "Sensors" As I recall' date=' the motion detectors in ALIENS were not reality based, but it has been many years. Current motion detectors use radar or sonar. What did ALIENS use?[/quote'] Micro-changes in air density? Quote Link to comment Share on other sites More sharing options...
Kraven Kor Posted August 5, 2009 Author Report Share Posted August 5, 2009 Re: (Somewhat) realistic "Sensors" Micro-changes in air density? Right, and mine will be a little more grounded in reality. They won't be able to sense motion through walls, though they might detect that the wall is vibrating from possible motion they won't be able to pinpoint what is causing it. Their motion detectors will basically only detect within "line of sight" using a variety of methods, possibly including Radar, Sonar, Light Sensors, etc. So yeah I want a semi-believable motion tracker that works over about 20 meters for the handheld variety (or further, if feasible.) Quote Link to comment Share on other sites More sharing options...
Yansuf Posted August 5, 2009 Report Share Posted August 5, 2009 Re: (Somewhat) realistic "Sensors" Micro-changes in air density? I thought that was what the "alien detector" used in ALIEN. Anyway, microwave or millimeter wave radar will work, as will sonar; but note that these are both active sensors. The only way I can think of to do this with a passive system would be a "camera" system (visible and IR) with a computer analysis of changes to detect motion. Quite feasible for a stationary sensor; possible for a moving one but probably requires much better computer technology than currently available. (Of course that may not be true in a few years.) Quote Link to comment Share on other sites More sharing options...
ajackson Posted August 6, 2009 Report Share Posted August 6, 2009 Re: (Somewhat) realistic "Sensors" A passive sonic or vibration detection system can do a decent job of direction finding. However, it can't really be carried around by a human, because if so it will detect a great big motion source right next to it, swamping any lesser signatures. You'd want to place them on the ground and leave them. Quote Link to comment Share on other sites More sharing options...
Kraven Kor Posted August 6, 2009 Author Report Share Posted August 6, 2009 Re: (Somewhat) realistic "Sensors" A passive sonic or vibration detection system can do a decent job of direction finding. However' date=' it can't really be carried around by a human, because if so it will detect a great big motion source right next to it, swamping any lesser signatures. You'd want to place them on the ground and leave them.[/quote'] Well, their motion trackers will be built into their uniforms / armor. So it can compensate for your own motion, I would think? Edit: Again, this is 300 years in the future, and the "PDA" of their suit is probably more of computer than even the largest current supercomputers. Quote Link to comment Share on other sites More sharing options...
Curufea Posted August 6, 2009 Report Share Posted August 6, 2009 Re: (Somewhat) realistic "Sensors" I've always hated the FTL sensors of Star Trek. Not just because it completely invalidates the point of the "Picard Manoeuvre" but because it negates many really good story ideas. With realistic sensors, you actually have to make decisions before you know what's out there. Quote Link to comment Share on other sites More sharing options...
Tom Carman Posted August 6, 2009 Report Share Posted August 6, 2009 Re: (Somewhat) realistic "Sensors" I've always hated the FTL sensors of Star Trek. Not just because it completely invalidates the point of the "Picard Manoeuvre" but because it negates many really good story ideas. With realistic sensors' date=' you actually have to make decisions before you know what's out there.[/quote'] A search of the forums will probably turn up a discussion of "longscan" from C.J. Cherryh's space novels. IIRC it combined radar, computer projection, and the inspired guesswork of the human operator. Quote Link to comment Share on other sites More sharing options...
Nyrath Posted August 6, 2009 Report Share Posted August 6, 2009 Re: (Somewhat) realistic "Sensors" A search of the forums will probably turn up a discussion of "longscan" from C.J. Cherryh's space novels. IIRC it combined radar' date=' computer projection, and the inspired guesswork of the human operator.[/quote'] You can read about it here: http://www.projectrho.com/rocket/rocket3w.html#longscan Quote Link to comment Share on other sites More sharing options...
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