It’s a loose comparison, since both asphalt and the moon’s surface vary. Plus, there are tricky things like specular reflection and the opposition effect.
How can its color be compared to something on earth? Doesn't the (lack of) atmosphere have some effect?
You can hold a moon rock up against something on Earth. Or you can look at Earth and the moon from a distance with the same sensor, which is what Himawari-8 is doing.
The atmosphere does affect things: A huge plain of moon rocks on Earth’s surface would look bluer (hazier) than the moon would in the same picture from Himawari-8 (or an Apollo Hasselblad, etc.). And a moon rock in sunlight on Earth will look slightly yellower than one in the same light on the moon. But your eyes are constantly adapting to the surrounding illumination. Color perception is really complicated.
Casual readers may not get your reference – the idea for DSCOVR literally came to Al Gore in a dream. I still think this is hilarious.
One can indeed argue that DSCOVR has merit, and people including climate scientists do. (Though arguably it’s really too early to judge either way until there’s time for publications to come out of its data.) Earth’s radiation budget is surprisingly underdetermined, considering its importance.
But it’s certainly a fair criticism of DSCOVR as launched that it’s not state-of-the-art. That’s because it was delayed for reasons of politics, only loosely disguised as reasons of science.
The only places I’d push back on your remarks are:
1. The “Uh no”, which is unsubstantiated (perhaps just facetious, but I’m sensitive because I supported my point relatively laboriously, with the links); and
2. the idea that the NYT should refrain from pointing out political interference in science funding.
Discovery at Udvar-Hazy is why I started this project. I saw the serial numbers on the tiles – almost close enough to touch on tiptoe – and remembered reading about some kind of database. I imagined a visualization with a line for every tile over time, and decided to find the records to make the viz.
That was two years ago. I’ve asked a lot of people since then, but after making a web site for the project (on @doingitwrong’s advice), this week is by far the most attention it’s gotten. I’m hoping this is what finally gets word to someone who knows something.
> The environmentalist threw a fit about this "glue" and it was replaced with a glue that all the engineers said was not as safe, in regards to the tiles staying attached...
In the images in the blog post and the live map? Those aren’t pansharpened at all. If we do add pansharpening in a later version, it’ll likely be naïve, without spatially aware modeling of the multispectral data. (Specifically, it’ll probably be a cleaned-up, rasterio-based, null-aware, parallelized descendant of this sketch of the Brovey transform in numpy: https://gist.github.com/celoyd/2e7beed82951d22b9b90 .)
From what I’ve seen – and I haven’t tested it carefully yet, so I could be wrong – the more elaborate methods are severe overkill on Landsat 8. It has only 4 pan px per multi px (where some commercial data has 9 or 16), and the pan band is almost exactly R+G+B (without NIR). So my gut and some simple experiments suggest that doing PCA-or-whatever is overthinking it.
I wrote that Mapbox post, and helped with some of the processing that happens to get this data on AWS. Yep, you get multispectral resolution of 30 m, and with pansharpening (http://en.wikipedia.org/wiki/Pansharpened_image, etc.) you can get visually acceptable quality at 15 m in RGB.
Landsat is basically intended for science about seasonal/annual/decade-scale changes in Earth’s land surface. When you see an estimate of how a city’s built-up area has grown since 1980, or how the Everglades are changing, it probably has Landsat as one source. This explains a lot of design decisions that might seem weird to a layperson who wants to use it for everyday RGB imagery. Most use of Landsat imagery is basically off-label. It’s just very good data in terms of accuracy, precision, and general ease of use. And if I say so myself, it looks real pretty: https://www.mapbox.com/blog/landsat-live-live/
By eyeball, that’s 0.08 m over 2003–2011, or just about 1 cm/year. (Notice the tabs on the bottom: the x and y velocities also show clear trends. That’s continental drift. And when the news says something like “the earthquake permanently moved the ground almost two feet south”, the data comes from observatories like this one, among other methods.)
Purely speculating, not going on anything they’ve said: theoretically when they have more satellites you might be able to patch together a larger area with simultaneous video from several birds. You’d have a slightly ugly angle difference at the seam, of course. There may be technical constraints here that I’m not thinking of, though.
In any case, at 1 m GSD and 30 fps, 1.1 by 2 km is 66 megapixels a second. Even efficiently compressed, that’s a lot of information already.