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/
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.
> Pansharpened Malibu, 15 m (50 ft) per pixel. Notice the wave texture in the water.
Ugh, Brovey. There's better options available. Like MMP (really low spectral distortion but can be slow): http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6677587) or even affinity/guided filtering (my own paper, more spectral distortion than MMP but a lot faster and you can sharpen hyperspectral with multispectral or RGB): http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7008094.
Part of what sounds interesting to me in the longer-term vision for the dat project is the ability to write transformations that point to a living data source and output an up-to-date parsed/processed version of it (and only download diffs!). Processed data sets tend to be stale, or alternatively you have to start from a data dump and run a slew of scripts to process or index the data, which can take days.
One painful example of this problem was Freebase's very interesting data set, WEX (pairing Wikipedia textual content with structured data from Freebase), of which there is an outdated snapshot on AWS Public Data Sets containing less than half the data of newer versions. Google acquired Freebase a little while before then, and there were only one or two updates to WEX. I was lucky enough to download what I think was the last WEX data dump before they killed the download.freebase.com subdomain. I have yet to confirm if it's gone or if it was simply moved/renamed.
While it was amazing Freebase/Google provided dumps this processed data, and Amazon provided an easy to access snapshot of it, we really ought to have a way of publishing and subscribing to the latest post-processed version of a data set derived from one or more regularly updated data sets, be they from NASA/Landsat, Wikipedia, or otherwise. I don't know exactly what this process would look like, but the raw data is there and all we need is a way to publish the processing software/commands (docker?) to be re-run whenever a data dependency is updated.
It seems like AWS Public Data Sets would be an ideal destination for data sets and more accessible derivatives. Is any of that in line with the intent of AWS Public Data Sets?
I apologize for letting that turn into a bit of a rant, but I wanted to provide an anecdote and context.
ATI tried to recruit me for consumer products, but their understanding of image processing was so primitive that we couldn't communicate. All they understood was red-eye removal and edge detection. :)
The various Landsat resolutions are ok for earth sciences, including ground cover, cloud cover and ice studies.
But I think most of the people here would be more interested in Spot or higher resolution data.
An interesting factoid is that one of the earliest Sony CD-ROMs ever burned (1985'ish) had Landsat sample data on it. It was distributed to a few Japanese geoscientists who had an obvious need for mass storage.