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Satellites Taking Pictures of Rockets Carrying More Satellites

planet.com

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Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#21

Post by notahacker »

Pica_soO wrote: post #20
notahacker wrote: post #16

Earlier quoted context omitted.

Satellite image prices through a broker, including Planet's RapidEye constellation http://www.landinfo.com/satellite-imagery-pricing.html Prices are per square kilometer, but there's a minimum order of 500 square kilometers, and you're paying for a licence for a certain number of people to use them in a certain way. TLDR: best have at least a few hundred dollars handy even if you're only wanting to look at one city.…

Has somebody recombined low res data from many satellites to a high res free version? Sort of like many synced cheap oscilloscopes can form a expensive one?

There is pansharpening (effectively improving the spatial resolution of colour images by combining them with sharper, higher spatial-resolution monochrome images) and using processing techniques to combine low-res images can certainly improve the effectiveness of detecting features which are smaller than the image pixel size, but I don't think anyone's likely to get comparable detail to a sub-1m or even a 5m pixel image out of combining 20m and 30m pixel images taken at different times.

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#22

Post by mseebach »

dopeboy wrote: post #15

Kind of offtopic but I figured I'd ask: how close are we to enemy of the state style satellites that can track movement like a overhead CCTV camera?

There are probably satellites capable of very high resolution pictures, but tracking a person with a continuous video feed is probably not practical - you'd need a ridiculous number of satellites due to the orbit.

What we do have, and have had for a couple of decades, is drones, and they can definitely do that.

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#23

Post by jessriedel »

notahacker wrote: post #16
siscia wrote: post #14

Any of you have any idea of how much the images from planet.com cost?

Satellite image prices through a broker, including Planet's RapidEye constellation http://www.landinfo.com/satellite-imagery-pricing.html Prices are per square kilometer, but there's a minimum order of 500 square kilometers, and you're paying for a licence for a certain number of people to use them in a certain way. TLDR: best have at least a few hundred dollars handy even if you're only wanting to look at one city.…

Any idea why the minimum area requirements exist? It completely kills localized applications like a single farm. It seems like a minimum price, which you could also reach by committing to buy regular photos for a period of time, would be a lot more flexible.

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#24

Post by DiThi »

oelmekki wrote: post #19

Each time I'm sad we're not exploring galaxy star trek style yet and the space conquest made a flop, I remember how many commercial satellites are around here. It really has this regular taste of things you think just died after being hyped (the moon landing) and which you suddenly realize has got slowly, steadily, discretely omnipresent since then without anybody noticing much (granted, satellites are not as cool as…

You may be excited about SpaceX plans.

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#25

Post by tenpies »

oelmekki wrote: post #19

Each time I'm sad we're not exploring galaxy star trek style yet and the space conquest made a flop, I remember how many commercial satellites are around here. It really has this regular taste of things you think just died after being hyped (the moon landing) and which you suddenly realize has got slowly, steadily, discretely omnipresent since then without anybody noticing much (granted, satellites are not as cool as…

It has basically fallen into a classic hype cycle - https://en.wikipedia.org/wiki/Hype_cycle

This is partly why I'm skeptical of technologies when the media is talking about them. It probably means we're somewhere on the peak of inflated expectations.

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#26

Post by oelmekki »

tenpies wrote: post #25
oelmekki wrote: post #19

Each time I'm sad we're not exploring galaxy star trek style yet and the space conquest made a flop, I remember how many commercial satellites are around here. It really has this regular taste of things you think just died after being hyped (the moon landing) and which you suddenly realize has got slowly, steadily, discretely omnipresent since then without anybody noticing much (granted, satellites are not as cool as…

It has basically fallen into a classic hype cycle - https://en.wikipedia.org/wiki/Hype_cycle This is partly why I'm skeptical of technologies when the media is talking about them. It probably means we're somewhere on the peak of inflated expectations.

Indeed - Elliott waves come in mind too. As un-scientific as those ideas can be, not being expressed in any kind of mathematics, they seem to point at some possible reality in growth patterns. Notably, the fact that there's always a plunge after a first surge - where everybody think it's dead and where it starts a new uptrend - is something that makes me really curious.

Note that it's not just about people expectation either : humans actually went on the moon, they didn't just talk about it, and they didn't go any further in decades. So beside expectation, it doesn't seem far fetched to say there indeed was a plunge in achievements, at least if we consider distance traveled by humans (which should grow again when/if we go on Mars).

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#27

Post by jessriedel »

andrewstuart2 wrote: post #11
jessriedel wrote: post #8

Earlier quoted context omitted.

If bandwidth were the main limiting factor, they would just take video intermittently and downlink it over a long period of time. This would be useful for documenting real-time changes on the ground during important isolated events (e.g., rocket launches). But they apparently don't have this capability, and I think it's because the hardware for taking many frames per second just isn't worth the cost and complexity.

As mentioned in parent, the rate you can capture depends on the resolution (i.e. image size in bytes), downlink speed, available memory, and length of the event. As the length of the event approaches infinity, the framerate you can capture is basically bandwidth / image size. `(mb/s)/mb = 1/s` (aka hz). Beyond that limit, the memory size / image size gives you a hard limit for the number of additional frames you can…

I don't think memory is limiting design factor either.

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#28

Post by Iv »

dopeboy wrote: post #15

Kind of offtopic but I figured I'd ask: how close are we to enemy of the state style satellites that can track movement like a overhead CCTV camera?

20 years ago they pretended it was good enough to differentiate between Saddam Hussein and his decoy lookalikes.

It is possible however that they made that up to not reveal an internal source of intel.

I, for one, think we have been there for a while. The tech is not hard: camera with huuuuge optics will bring you there.

The military have secret satellites with undisclosed specs, that's what they have been doing since Sputnik. You bet they are good at it by now.

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#29

Post by nine_k »

jessriedel wrote: post #23
notahacker wrote: post #16

Earlier quoted context omitted.

Satellite image prices through a broker, including Planet's RapidEye constellation http://www.landinfo.com/satellite-imagery-pricing.html Prices are per square kilometer, but there's a minimum order of 500 square kilometers, and you're paying for a licence for a certain number of people to use them in a certain way. TLDR: best have at least a few hundred dollars handy even if you're only wanting to look at one city.…

Any idea why the minimum area requirements exist? It completely kills localized applications like a single farm. It seems like a minimum price, which you could also reach by committing to buy regular photos for a period of time, would be a lot more flexible.

I suspect it's related to the need to possibly re-orient the satellite to have a particular place visible by the camera. It must be relatively slow, and possibly even cost reaction mass, thus the commitment to shoot more of the same area.

Re: Satellites Taking Pictures of Rockets Carrying More Satellites

#30

Post by kevin_thibedeau »

orbital-decay wrote: post #10
wollstonecraft wrote: post #9

Earlier quoted context omitted.

Their satellites have a one dimensional sensor that scans continuously.

They are using 2D TDI CCDs, just like everyone else. This timelapse was likely shot with frame by frame exposures though. I'm not sure how it's possible with TDI.

Still inherently 1D. TDI sensors are not like area arrays.
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