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Do you think this can be done? Like google earth but real time. For example, If I went out of my house and waved to the cloudless sky in the day time could someone in the NSA watch me do it? Do you think this will ever get in the hands of the common person? A google earth update ; now with earth cam zoomable to 40 feet above ground! That would be insanely cool, but also pose many problems. Unmanned drones suggest to me this isn't a reality, but that could just be the result of red tape. |
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I think it is quite possible but I think what is lacking is the man power to make this level of surveillance a reality... |
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Im all for it, purely for my own entertainment. Get out of the way cloud, your blocking my view. |
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The NSA can watch whatever they want. And it's scary, not entertaining. |
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Its scary that they can, yes, but it would be entertaining for me. I think it is coming. Ive been reading abou tit and there are companies trying to get this into reality as we speak. |
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Most girls toilets have a roof, you fool! |
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BB |
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xray satellites then.. yeah |
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For example, If I went out of my house and waved to the cloudless sky in the day time could someone in the NSA watch me do it? heheehee |
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crazy good war overview camp, it'll be like a game of warcraft. that'd be great. |
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kill all the white men |
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There'd always be some amount of delay, but it probs would be possible. |
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if you're doing things you shouldn't be outside in the open you have other things to worry about besides sattelites that can see you |
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drexciya! 23,500 MILES FORM EARTH!!!! |
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ok, you have things like low earth orbit, and geosycnhronous/stationary orbit. most comm sats/tv sats/etc are fixed in the sky. meaning they are some 23,500-26000 or wahtever # miles from earth. they rotate around the earth at the same speed as it spins, so technically they are matched and the satt. appears fixed in the sky. now imaging satellites and things of that nature, orbit the earth at like 8km/s. they are generally like 1200 miles from earth (i think???) ... so they appear as "moving" across the sky because they are orbiting the earth because of the closer distance. now think about it if you want "real time" imaging... ad-hoc, at any point anywhere, the only way you are going to do this is with a geosynchrnous mesh of imaging satellites... ok so why hasn't this been done? well, 23,500miles is a LOT further away than 1200 miles. i don't think yer image would be as close/clear/sharp ;) |
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The main problem with this idea, although very cool, is that the type of satalites that are traveling over the planet taking pictures for things like Google Earth are traveling at 11 meters a second. TV satalites remain relitavely still in the sky because they are "falling" at around the same speed as the earth is turning (Clark theory). I hope this clears this up for you.. |
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little bit faster than 11meters a second, my friend |
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I thought that was terminal velosity, or there abouts. I have been wrong in the past but it is very rare. |
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terminal velocity isn't really possible in space (a vaccum) i.e. when you cannot accelerate anymore. gravity is 9.8meters/s. you would reach 11meters a second in just over 1 second. sorry but that's wayy off. |
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Please, I beg you two to tell me how the FUCK you know this information and with such confidence? Oh, and I have trust in break throughs. Fingers crossed. Why couldn't they fit better cameras, when technolgy allows, on the google earth Sats in the future? |
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I thought terminal velocity was context sensitive (the fastest you can (naturally) go in the current environment) and not a set speed..? how can you not, by falling, reach the highest possible speed? |
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re-read what i wrote "terminal velocity isn't really possible in space (a vaccum) i.e. when you cannot accelerate anymore." by "environment" you mean "atmosphere" wher ethere is wind/air resistance/drag. hence, your velocity can no longer increase because you cannot penetrate the oh fuk it let me wiki it and find out how to say it properly |
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The reason an object reaches a terminal velocity is that the drag force resisting motion is directly proportional to the square of its speed. At low speeds the drag is much less than the gravitational force and so the object accelerates. As it speeds up the drag increases, until eventually it equals the weight. Drag also depends on the cross-sectional area. This is why things with a large surface area such as parachutes have a lower terminal velocity than small objects like cannon balls. |
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so you mean there is no limit in a vacuum; you can always go faster and faster? |
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and I didn't really necessarily mean atmosphere by environment, no.. I meant stuff like gravitational pull, etc (all environmental variables), which I presume would be different on earth and on the moon even if they had the same atmosphere... |
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"Please, I beg you two to tell me how the FUCK you know this information and with such confidence?" umm, it's pretty well known there are a few stages of orbit, low earth orbit (LEO), MEO, and GEO (geosynchronous). now, sure there HAVE ALREADY BEEN and still may to come ... increased optics technology. but I don't see any "insane breakthrough" anytime soon. if anything, it's technology within the optic sensors, not the optics themselves that will evolve . different satellites perform different functions. face it, multi(m/b)illion dollar optics just don't perform the same when you are 120-1200 miles away vs 23,500 miles away. when you are in GEO, the satellite is in a static vector to someone on earth. it is rotating relative to the spin/speed of the earth. hence it doesn't "move" across the sky. this is where your comm satellites are and TV satellites. it would be a bitch (and expensive) to have your receiver/dish to move/track a satellite for TV or internet. also, since 23,500miles away is quite a distance, and the speed of light is now considered the bottleneck ... this is why you see MINIMUM 200+ms response times from satellite internet. |
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" so you mean there is no limit in a vacuum; you can always go faster and faster? " not sure if this has been proved yet, but terminal velocity EXISTS because of air drag/resistance in atmosphere. in space, there isn't much (read: none) air resistance, now is there |
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"and I didn't really necessarily mean atmosphere by environment, no.. I meant stuff like gravitational pull, etc (all environmental variables), which I presume would be different on earth and on the moon even if they had the same atmosphere... well of course terminal velocity isn't a STATIC value ... i never said that |
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but there is, for instance, the theoretical limit of the speed of light which would require enormous amounts of energy to cross (supposedly), which would constitute a sort of at least theoretical terminal velocity.. and then there's, like with the satellites, a sort of upper limit to how fast they can fall while remaining in the orbit they've been put into due to the gravitational pull.. of course, they have the potential to fall faster, but then they'd have to be removed from their current environment which includes the earths gravitational pull..? |
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imaging satellites are in LEO for a reason. but, since they are in LEO they are "orbiting" the earth. hence when doing military imaging over another country, it isn't very difficult for that country to know the predicted orbital path of that satellite and say. ... "put blankets on top of their shit" or "put shit away" when the sat. passes by to take photos if you wanted "real time imaging", you could do it with a sat. in LEO, but it will be passing over the target, hence you can't get a photo of say, your house .. anytime...youd have to wait for it to pass over. sats now can do real time, obviously. and have been, but in the case of what you're looking for, you would need a sat. in GEO in which case, image quality will be severely degregated |
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no, but even the satellites are within some context where they don't fall faster than they do, faster than they are able to... |
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"but there is, for instance, the theoretical limit of the speed of light which would require enormous amounts of energy to cross (supposedly), which would constitute a sort of at least theoretical terminal velocity.. and then there's, like with the satellites, a sort of upper limit to how fast they can fall while remaining in the orbit they've been put into due to the gravitational pull.. of course, they have the potential to fall faster, but then they'd have to be removed from their current environment which includes the earths gravitational pull..? " air doesn't really have "resistance" properties, like normal mass does. that is part of the definition of terminal velocity. the space shuttle is in LEO. when you see it in pictures in space, it is actually falling to the earth. but since it's horizontal velocity is so fast, it is actually falling WITH the curvature of the earth, same with satellites in LEO |
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"no, but even the satellites are within some context where they don't fall faster than they do, faster than they are able to... " satellites can fall as fast as they want to from grav pull. then they hit the atmosphere and incurr resistance (hence the space shuttle/anything re-entering the atmosphere... they are traveling EXTREMELY FAST, and they start hitting atmosphereic resitances (air) which SLOWS THEM WAY DOWN... this is an extreme amount of energy. they do this to increase drag and slow their speed |
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"air doesn't really have "resistance" properties, like normal mass does. that is part of the definition of terminal velocity. " *light doesn't really have .... |
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you mean they bounce in and out of atmosphere all the time? then the lower ones are still inside the atmosphere? or do the higher up ones vary their distance from earth very very much? |
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i haven't studied up on this stuff in sometime go to www.wikipedia.com the explanations will be far greater than anything i can explain im sure. lookup then at the bottom "see also" click those links. yes im reading thru now they explain it much better (obviously) with greater accuracy |
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so terminal velocity is some kind of term that is not the same as saying something has a maximum velocity? |
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"you mean they bounce in and out of atmosphere all the time? then the lower ones are still inside the atmosphere? or do the higher up ones vary their distance from earth very very much? " no they don't bounce. it is a static trajectory (slight offset, which is why they slowly over many years slip back into re-entry and burn up). are your altitute increases, your horizontal velocity also much cahnge to continue to fall/travel at the same rate as the curvature of the earht, |
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terminal velocity does not = maximum velocity terminal velocity has a specific meaning/reason. when you say maximum velocity, you could have MANY factors limiting you (it's a vague term) |
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*context sensitive maximum velocity |
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what i was saying above, in LEO you have to deal with atmospheric drag, but that's not the scope of this discussion |
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but then, if they don't come into contact with the atmosphere, how do the geostationary satellites, for instance, keep their velocity so close to constant? |
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Orbital period= 24 hrs = 1,440 minutes = 86,400 seconds Satellite height = 35,900km = 35,900,000m Earth’s radius = 6,378km = 6,378,000m Orbital radius 35,900,000m+6,378,000m = 42,278,000m Orbital circumference = 2*3.14159*42,278,000m (c=2*Pi*R) = 265,640,284m Orbital speed = 265,640,284m / 86,400 seconds = 3074m/s I'm too lazy to do all the math for the gravity and everything, but this should be right I think. |
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terminal velocity can = maximum velocity but maximum velocity does not always = terminal velocity |
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They're constantly "falling" around earth at a set height, which means that gravity stays the same, which means that their velocity is pretty close to constant. I don't know, I'm sure someone can explain it better than that, but that's how I understand it. Their gravitational potential energy is being kept steady, so their speed is too. |
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no, the main point of the discussion was that someone wanted to be able to use satellites to monitor people, and even if this is a somewhat real situation (though not in the form of pictures, but in more and more objects that you carry with you often having built-in gps so it would be able to determine your position, and the fact that there is no legislation on this (at least not here in norway yet)), I found this to be more interesting for some reason. |
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but then, within those circumstances, are they not reaching their terminal velocity? I find it a bit odd that atmosphere should be a necessary factor in that term... |
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satellites are not in terminal velocity they are set at a SET VELOCITY so that they dont LEAVE EARTH"S ORBIT. satellites in LEO, ORBIT earth at a SPECIFIC velocity to maintain a CONSTANT orbit AS they are FALLING TO EARTH since this speed is FAST enough, they are CONSTANTLY FALLING AROUND THE CURVATURE OF THE EARTH. this has NOTHING to do with terminal velocity (which can exist because of atmospheric drag in LEO). -------------------- the orignial question was about imaging satellites and being "locked on to someone" anytime, anywhere, for any period of time like i said WAY above the only way to accomplish this is to have imaging satellites in GEO (because they would be a fixed point in the sky, that could point their optics anywhere on the facing side of the earth). since all imaging satellites are in LEO, they are CONSTANTLY ORBITING THE EARTH hence, these satellites QUICKLY FLY ABOVE YOU are a PREDICTED TIME/ORBIT PATH. hence, you cannot satisfy your requirement for "imaging anytime, anywhere" with LEO imaging satellites unless you had a COMPLEX ARRAY OF SATELLITES IN LEO THAT WORKED AS A MESH. even that would be weird. hence, to do your requirement, satellite would need to be in GEO which means a SHITTON FURTHER AWAY = IMAGE DEDEGRATION |
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"but then, within those circumstances, are they not reaching their terminal velocity? I find it a bit odd that atmosphere should be a necessary factor in that term... " ATMOSPHERE IS PRETTY IMPORTANT BECAUSE THE WHOLE DEFINITION OF TERMINAL VELOCITY IS BASED AROUND AIR/WINDOW RESISTANCE AND DRAG BECAUSE OF THIS DRAG, YOU CANNOT ACCELERATE/OVERCOME IT ANYMORE TO INCREASE YOUR VELOCITY. THAT IS THE WHOLE DEFINITION OF IT !!! satellites in LEO still are in "atmosphere" and are affected by this resistnnce, hence ATMOSTPHERIC DRAG concept |
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A parachute wouldn't work in space because there would be nothing to inflate it, nothing to drag against the nylon and create the friction that stops you from falling faster as gravity (or whatever force) pulls you. Therefore, the parachute could go as fast a it wanted without atmosphere, so its terminal velocity does depend on atmosphere. There is terminal orbital velocity though, which is the speed you have to stay under to actually keep orbiting a body like earth... but that's pretty fast in this case. |
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