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Planet: Imaging the entire Earth every day

nbremer.github.io

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Re: Planet: Imaging the entire Earth every day

#91

Post by the_seraphim »

tonyarkles wrote: post #88
hanniabu wrote: post #44

Earlier quoted context omitted.

Ehhhh, the aircraft flew into the trajectory, are there no other comparable scenarios where there's an intersection that can happen accidentally?

Basically, if you're planning on pointing a laser into the sky, you need at a minimum issue a NOTAM to inform aviators of the hazard. Things like outdoor concerts and some weather observation systems do this. But... Sending a laser into the sky and intersecting an aircraft that was operating per regulation? That's on the laser-er, and "creating a hazard to aviation" is not a charge that you'll be happy dealing with i…

sending a NOTAM isnt hard... you could put in a permenant notam.

Also you wouldnt need a laser just a really bright searchlight

Re: Planet: Imaging the entire Earth every day

#93

Post by rzimmerman »

mirashii wrote: post #16
mrhappyunhappy wrote: post #13

So many questions: 1. How did they get 150 satellites into low orbit? 2. Is it becoming a hazard to have all the satellites and space junk possibly making it difficult to launch anything down the road? 3. Aside from tracking the objects, has anyone made any calculations as to when these things will become a hazard?

1. Many of these satellites are cubesats. They hitch rides as secondary payloads on launches, and in batches. In Planet's case, they've launched many batches, some as large as 20-48 satellites. 2. Not really. Kessler syndrome is the general name for this phenomenon, but it's not a huge concern in LEO. In LEO, there is enough atmospheric drag to naturally deorbit spacecraft. For US based companies, regulations mandate…

Thanks for this really concise answer. Here's a paper we did a while back that lists the launch history and some of the different orbit types of the Dove satellites: https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=3...

Re: Planet: Imaging the entire Earth every day

#94

Post by slenk »

crazygringo wrote: post #92

Super cool! I wonder why both clouds and ocean show up as black instead of as actual white and blue imagery respectively. Are they saving money and bandwidth by not sending back "useless" imagery? Or something else?

Pretty sure its black because they don't image them as its a waste of bandwidth

Re: Planet: Imaging the entire Earth every day

#95

Post by kartikkumar »

azernik wrote: post #86
Dunedan wrote: post #27

"Omega tau" made a really nice podcast a while ago about how Planet Labs is approaching Earth observation. That podcast goes into the details how the company and the satellite constellation came to be and what novel approaches they're using. Definitely worth listening: http://omegataupodcast.net/204-earth-observation-at-planet-l...

This is fascinating - especially the talks about the advantages of using COTS electronics. Once upon a time, the latest and greatest in electronics was produced by military, scientific, and spaceflight applications, with commercial uses being spinoffs that were often up to a decade behind. Now the situation is reversed; consumer electronics are where the innovation is happening, and military/space systems are finding…

There's actually strong synergy. There's a lot of spin-in and spin-out going on between space and non-space sectors.

COTS and general commodization of "discete units" (parts, subsystems, assemblies, etc.) is one of the biggest drivers for the commercialization of space. It's enabling people to move towards the use of advanced manufacturing techniques, cutting lead time and cost, and enabling batch production.

We recently published an article on how manufacturing lines are changing in the space industry, inspired by best practices in mature commercial sectors like the auto industry: https://blog.satsearch.co/2019-08-08-demystifying-auto-indus...

We see a lot of this happening through our website: https://satsearch.co. We're effectively building a B2B marketplace because of this specific change in the way supply chains are being architected.

Disclosure: I'm one of the co-founders at satsearch.

Re: Planet: Imaging the entire Earth every day

#96

Post by stronglikedan »

joshvm wrote: post #89
bainsfather wrote: post #74

Earlier quoted context omitted.

What is he resolution like? Is it as good as Google's aerial imagery that they show with their maps? (or Bing's)

Both Bing and Google use aerial imagery with centimetre-scale resolution (certainly 25cm). PlanetScope is 3m I think, the totally free stuff like Sentinel 2 is 10m (5 day revisit). The best commercial imaging satellites are <0.5m. Below that it's simpler to use aircraft.

3, 5, and 0.72 meter resolution [0]

[0] https://www.planet.com/products/planet-imagery/

Re: Planet: Imaging the entire Earth every day

#97

Post by SiempreViernes »

ivanhoe wrote: post #66
tunesmith wrote: post #29

I can't believe I've never wondered this before, but I wonder how possible it is to deliberately create a satellite-blocking cloud above one's own property. What height and size it would have to be, etc.

It's called anthropogenic clouds, and it's possible but requires certain weather conditions to work: you need a source of water vapor that can saturate the air, and a stream of cold air to condensate that vapor. Then it's possible to launch particles into the air that would act as cloud condensation nucleus, and in theory it should start the cloud formation. Anyway, to hide a small area much easier solution would be…

The more common approach is using a large roof, and after that to build where it is usually cloudy.

Re: Planet: Imaging the entire Earth every day

#98

Post by whatshisface »

For the people commenting on the Firefox+Linux issue: it doesn't work for me, and this is the error I get:

>Refused to create native OpenGL context because of blacklist entry: FEATURE_FAILURE_OLD_NVIDIA

So the real combination is Old NVIDIA drivers + Linux + Firefox. (Maybe not even Firefox, the issue might be inseparable from my old card. I'm not going to try it on Chromium.) The question is, why is my card blacklisted? I think it might be because of a security vulnerability that Chrome hasn't patched.

Re: Planet: Imaging the entire Earth every day

#99

Post by jofer »

crazygringo wrote: post #92

Super cool! I wonder why both clouds and ocean show up as black instead of as actual white and blue imagery respectively. Are they saving money and bandwidth by not sending back "useless" imagery? Or something else?

Most cubesats have small solar panels and can't image all the time (i.e. they need to charge and then image). Mostly likely there no imaging at all over the oceans so the satellites can charge.

Re: Planet: Imaging the entire Earth every day

#100

Post by gjstein »

dougmwne wrote: post #79
bainsfather wrote: post #74

Earlier quoted context omitted.

What is he resolution like? Is it as good as Google's aerial imagery that they show with their maps? (or Bing's)

No way, not even close. At this point Google is doing overhead lidar flights to get incredibly details 3d maps. The Planet imagry is like going back several decades in satellite tech. But on the other hand, it's daily.

Do you have a source for "overhead LIDAR flights"? I was under the impression that data was coming almost exclusively from their StreetView cars (with perhaps a few companies that provide helicopter-based data from time to time). True enough though that Google has a staggering amount of data about the earth.
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