Inside voice, Adam.
In recent weeks, I had spent some time mucking around with Nasa's MODIS satellite imagery to try to deduce the size and extent of the Sierra snowpack. This is exactly the kind of problem that piques my interest. Usually, when I encounter these kinds of problems, I throw a few hours at it, do some really interesting stuff, but leave it incomplete and undocumented, because I saw something else shiny.
Well, this time I pledged to tug it a little further along, so I have. In typical Sierra Mapper style, this feature has been thrown in with abandon, mashed into a hole in existing code.
I'm still not sure what you're even talking about.
You'll see a new button at the bottom of the calculated route page, with a cryptic and exciting label of Snow?!? on it:
|Like any good GUI designer, I placed the button for the exciting new feature buried at the bottom of the laundry-list of existing buttons|
When you click on the Snow?!? button, you'll be whisked off to another screen. The screen is pretty plain, but shows three elevation profiles for your route. In atypical Sierra Mapper fashion, the elevation profiles are
|Edit: New! Way much more fancier-ish, and easier to interpret to boot.|
Well, there are quite a few of these. First and foremost, I haven't calibrated this approach with even a modicum of rigor, so I'm not sure how sensitive it is to snow cover. In other words, I don't know if 50% snow cover will trigger my analysis to report an area as snow-covered, or 80% or 10%. Ultimately, it simply has to do with the reflected light back to the satellite and the brightness (and whiteness) of the corresponding pixel in the satellite image. Since that will be affected by tree cover, by time of day, and by color temperature and brightness of the satellite image itself, there are a lot of variables that undoubtedly have an impact. Still, the approach finds that the entire Sierra is covered in January, and that none of it is covered in September, so it certainly works--but again, there is the question of sensitivity.
I hope to write more about the process in the coming weeks, and add both features and some polish. Still, I'm haphazardly throwing this feature up now in order to get it out while it was still relevant--adding this in August of a low-snow year would be a lot less interesting.
Lastly, as usual but especially since this was so hastily put together, please report any issues you encounter!