
Seeing Earth from outer space - callumlocke
https://pudding.cool/2017/10/satellites/
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isostatic
Really good, although this line annoyed me

"Communications satellites allow you to access the internet from your cell
phone, or make a call to the other side of the world."

No, that's what towers and undersea fibres do. I work with satellites -
they're a right pain when you're trying to use tcp over a bean with a >1sec
delay and trying to deliver broadcast quality pictures for the ten, andthey're
expensive when you're using a fixed station on the back of a truck, but we
only use those from random places in the middle of nowhere where there's no 3G
coverage.

99.99% of two-way communication traffic does not pass through a satellite, and
tre portion that does keeps decreasing. Even 10 years ago a live video with
someone in NZ would probably be bounced off not one, but two satellites,
before arriving in London. Now it will take a fibre to singapore and then
through Suez to France and into London that way.

Satellites are great at broadcasting to many people, andfor reaching the
middle of nowhere where there's limited infrastructure. They aren't a normal
means of communication though.

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fnwx17
Wait, there's an undersea cable from NZ to Singapore to the Suez Canal? How
many of these are in the world? The only ones I knew where UK to US.

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simonh
Enjoy.
[https://www.submarinecablemap.com/](https://www.submarinecablemap.com/)

Per Isostatic's point, Ive not worked with satellite comms but did work on
tracing financial transaction links all over the world. It al went by cable
and I remember having the conversations about why we didn't use satellites.
The latencies are terrible. In yet another life I spent some time working in
Saudi Arabia, the compound had a satellite internet connection and it was
terrible. The bandwidth itself was fine, but the delay between clicking
something and getting a response was painful.

The main problem is that most current satellite communications goes to
geosynchronous birds that are a long way out from earth. The low earth orbit
constellations companies like SpaceX are working on should mostly avoid the
latency issues because the hop up to the satellite and back down again should
be only a couple of hundred klicks instead of the 35,000 km plus, about three
earth diameters, out to GTO.

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shinners
That's pretty cool. Never knew they're were so many. Thanks for sharing this.

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weavie
Let's not forget this image of Earth from outer space :
[https://en.wikipedia.org/wiki/Pale_Blue_Dot](https://en.wikipedia.org/wiki/Pale_Blue_Dot)

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mxuribe
I'd never seen/heard of this! Its cool, though humbling...reminds me that
we're so small.

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weavie
Conversely, there are approximately 7 * 10^27 atoms in the human body and only
10^24 stars (estimated) in the known universe. So it some ways, we are also
very big.

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mrguyorama
This article is fairly lightweight from an information standpoint, but
interesting nonetheless. Particularly because of a project I've been working
on recently.

The Flight Simulator community works very hard to improve the massively
extendable Flight Simulator X system, and part of that includes creating
better scenery to fly around in. The gold standard for flight simulator
scenery is "Photoreal", where you lay pictures from satellites over geographic
elevation data to make beautiful vistas and allows you to do things like
navigate purely by following real world roads and landmarks. Unfortunately,
freely available satellite imagery is often resolution as low as 30 meters per
pixel, making low level flying a smeary, indistinguishable mess. This prompts
the community to turn to reverse engineering Google and Microsoft APIs and
breaking Terms of Service agreements in order to use their 0.3 meter per pixel
images.

The part that angers me is that, as an American, my government has signed off
on using potentially billions of dollars developing, deploying, and utilizing
highly advanced imagery satellites, and likely can reach inches per pixel.
Despite paying for all these satellites and their use, as well as a giant
datacenter in Utah, I have no way of utilizing these photos.

I believe that free access to high resolution satellite imagery would be a
public good, and many first world governments have the ability to create such
a thing. They could easily distribute 0.2 meter per pixel images without
compromising any sort of national security

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llccbb
Though not the resolution of WorldView (~50 cm), Landsat 8 can get you 15 m
resolution if you use pan sharpening. ESA's Sentinel 2 can get 10 m true-color
natively. Both these are free to use and Landsat images are public domain.
Copernicus data is copyright under ESA, but they are fairly permissive.

Over the US there is abundant true-color aerial imagery at resolutions of 1
meter that is freely available from USGS/USDA. I suspect there may be similar
datasets over parts of Europe.

Not trying to say these will solve all the problems you mention or that
scraping Google's tile server is specifically amoral, but the state of free
satellite imagery is better than it has ever been (haven't even talked about
weather satellites capturing images every 15 minutes!).

On the topic of defense contractors operating these high resolution satellites
and not sharing the data -- It isn't really true that you have no way of
utilizing these images. They are almost all available for purchase, albeit at
a very steep price. If you are interested in the Arctic/Antarctic you can
apply for free access to insane amounts of high-resolution data over the high
latitudes. Granted this is probably not the area you are interested in. You
can also apply for grants directly with Digital Globe if I remember correctly.

In many cases the satellite operators can't make every strip available because
they are mission-oriented. _Where_ the satellites are imaging can often be
classified information. Recognize that these aren't civilian satellites. They
are DoD contractors. Just because you can perceive the amount of data that
exists by looking at Google Maps doesn't mean it is for you. Consider all the
the National Geospatial Agency collects under funding from your taxes and the
mere crumbs that ever get let through to the public.

I am all for citizen access to very high resolution satellite products, but
from my experience it would be better to establish a new federal program that
operates in that way. More stability in that sense and less potential for
access to suddenly be revoked. If we can re-establish the mindset in DC that
federally operated science programs and open data are beneficial to every
american then we will be much better off in the long run.

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Sujan
Does scrolling back up to see something from before work for anyone reliably?
For me it always skips things, so if I scrolled over something (which happens
quite quickly while reading as there only seems to be a very small "sweet
spot") I can't really go back to it...

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dEnigma
Scrolling works, but the website nonetheless is downright unusable for me.
Clicking on links only works every fifth time or so and I constantly get WebGL
errors and am asked to reload the page.

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devkn0t
I'm having some visual bugs in the 3D rendering of the Landsat Satellite in
Firefox Desktop. It looks like a problem with the depth test or the culling.

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tones411
Well done!

