GOES-17 Releases ‘First Light’ Imagery from Its Advanced Baseline Imager | Hacker News Reader

GOES-17 Releases ‘First Light’ Imagery from Its Advanced Baseline Imager

nesdis.noaa.gov

95 pointsel_duderino24 comments

GOES-16 and GOES-17 are supposed to be identical, barring the cooling issue. Check out these fascinating loop-of-the-days from GOES-16. I'm sure they will be adding GOES-17 soon as well.

http://rammb.cira.colostate.edu/ramsdis/online/loop_of_the_d...

I had never noticed just how much cloud-cover there is globally. Wondering if it was just an artifact if the false coloring, I did a search. Turns out that that level of cloud-cover is normal[1]. Fascinating.

[1]: https://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MOD...

One of the primary science justifications for DSCOVR is its ability to measure the total combined reflectivity of Earth, dynamic cloud cover and all.

This albedo as it’s called is very important for climate science, and opposition to what climate science tells us about the world was an important part of the Bush administration deciding to not actually launch the finished satellite (the main reason being the overall idea was by Al Gore)[1]

All this is to say: check out these real images of the entire Earth https://epic.gsfc.nasa.gov/

[1]: https://www.airspacemag.com/space/al-gores-satellite-1809521...

> albedo

That's exactly why I found this so fascinating. I know that the ice caps are extremely important for slowing climate change (due to their albedo, being completely white). I had no idea that clouds were so prevalent. My initial thoughts on seeing that image were "wow, that's a lot of albedo, has climate change improved cloud coverage?" A directly counteracting force to the most dangerous GHG (water vapor). Turns out maybe not? We don't have industrial age data in this, so we can't tell for certain - but maybe (likely not) there is a glimmer of hope.

Thanks for the additional information, either way.

Clouds work both ways: They reflect short-wave visible radiation back into space, but they also send long-wave thermal radiation back to the ground and keep it warmer (compare your experience with cloudless nights to ones with clouds).

So far it looks like high clouds have a cooling effect and low clouds have a warming effect. We are not sure yet which clouds will increase more (this may not be up-to-date or might be known soon) but we expect more clouds in general in a warmer climate.

You have it backwards; the cirriform clouds are mostly transparent to visible but absorb and re-emit IR effectively (cloud greenhouse effect). Low clouds tend to have a very high albedo, hence effectively reflect incoming solar radiation, like ice/snow.

Indeed, thanks for the correction!

A lot of the global images of clouds (like this one [1]) are actually made from infra-red images, as making a visible composite is difficult. This means that they can only see high, cold clouds, so you only really see storms.

For example, the GOES-17 image shows large amounts of cloud off the western coast of South America. This is completely missing in the composite video, as it is very close to the surface and so almost invisible in the IR (it is close to the same temperature as the surface). About 2/3 of the globe is cloud covered on average [2].

[1] - https://www.youtube.com/watch?v=4wLYHyCiIyQ

[2] - https://www.atmos-chem-phys.net/10/7197/2010/acp-10-7197-201...

Unfortunately, the cooling system on this instrument isn't working as expected. We've got the visible spectrum, but not some of the long infrared wavelengths.

I wonder if this can be mitigated with software processing

Still, I wonder what kind of information can be gathered by long infrared here. Heat reflection/balance on the Earth? Climate Change related info?

Most of the goes-17 bands are in the ir, 14 out of 16, and their nicknames in this table gives some clue as to their use: https://www.goes-r.gov/education/ABI-bands-quick-info.html

That's very informative, thanks!

How long until satellites have their own service droids I wonder?

It seems amazing to me that cooling is an issue in space!

because space is a vacuum its actually really hard to cool things in space - there is no heat energy so it is cold, but there is no air for your generated heat to dissipate into.

https://physics.stackexchange.com/questions/72179/cooling-do...

Gorgeous.

And, as a curious artist— is the 'GeoColor' image composited by the satellite camera or done manually afterward in post? Mostly, I'd love to see raw stills of the different bands they reference in the image (like the infrared band).

I don't know the answer to your question, but I do have a link to the images you're interested in for GOES-16. Not sure if a similar page is available for GOES-17 mentioned in the article.

https://www.star.nesdis.noaa.gov/GOES/GOES16_FullDisk.php

GOES 16 and 17 are identical.

It is done automatically after the imagery is downloaded from the satellite.

They are complex combinations of multiple bands. The GOES-16 satellite has 6 (or 7, depending if you count shortwave ir) visible bands. Three are used for the red, green, and blue channels to get the "true color" image. Portions of other bands are used in combination with transparency to seamlessly combine the bands that show features the best. At night the IR bands are used in different combinations.

There's more information on the GeoColor products here: https://www.star.nesdis.noaa.gov/GOES/documents/QuickGuide_C...

The short version: daytime imagery is derived from GOES-16's red, blue, and near-IR (band 3) channels, with a simulated green channel. Night imagery's all IR; the base map (with city lights) is static and derives from a different satellite.

Related, you might want to check out DSCOVR- https://epic.gsfc.nasa.gov/

If you've never heard of it, this bird always stays on the sunlit side of the planet and takes true color images

This eclipse image reminds me of 2010 - https://epic.gsfc.nasa.gov/epic-galleries/2017/total_solar_e...

It takes actual full disk images too! None of this stitching shenanigance without the edge effects that all the geo orbit satelites do.

Goes-17 sees at best 2x2 km boxes (igfov depends on wavelength) and uses mirrors on servos to quickly scan the disk. DSCOVR is simply far enought away that it can see the full disk.

If you need reference materials for how earth like planets look from space, use DSCOVR images, everything else is fake!

> GOES-17 is the second in a series of next-generation geostationary weather satellites. Like GOES-16, its sister satellite operating as GOES East, GOES-17 is designed to provide advanced imagery and atmospheric measurements of Earth from 22,300 miles above the equator.

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