Algae blooms from satellite imagery (Landsat 8)

I’ve been lately tinkering with Libra, a free service to browse and download satellite imagery from Landsat 8 satellite.

This is an image from Landsat 8 satellite (2014-07-23) showing massive algal blooms at Archipelago Sea.

landsat_2014_07_23_web

You really should check this huge high resolution image to get a sense of scale.

Those tiny dots are large ships cutting through the algae mush:

landsat_closeup_1

Mining open source GIS data for Urban Snowboarding locations

Now something different.

Off-piste snowboarding in urban or rural areas is a time-consuming hobby especially outside the mountain areas, because the best spots are neither marked nor listed in city maps. A lazy snowboarder wants to find a nice, open hillside with decent slope and sparse treeline, but finding even a few spots requires numerous trips to countless would-be locations. But hey, we have open source GIS tools and Open Data to mine for just that!

So I opened up Quantum GIS and the Raster Calculator.

Continue reading Mining open source GIS data for Urban Snowboarding locations