dewline: Text: Searching and Researching (research)
On the DEWLine 2.0: Dwight Williams ([personal profile] dewline) wrote2023-04-09 09:59 am

Maps: Looking For Resources - April 2023

Okay. Now I have QGIS on my new-ish Mac Mini, and I've started downloading Shapefile data because that seems to be a thing you do when you have GIS software that you intend to use. Some of you are on my friendlist because you've provided insights on map design over the years, and I am wondering what else I should be looking at and looking for. This is a hobby of mine that seems to have made me slightly more useful in my most recent day job, which I consider a good thing. I want to keep building on that.
melita66: (Default)

[personal profile] melita66 2023-04-11 10:33 pm (UTC)(link)

Imagery/raster data, of course.

One thing you may run into is data that isn't georeferenced (term often used for raster data) which means the coordinates are raw cell counts. Or data is georeferenced but is missing the coordinate reference system (aka coordinate system aka projection) information. https://gis.stackexchange.com handles a lot of questions related to 'why doesn't my data line up?' I'm not going to be any good at how to do stuff in QGIS because I haven't used it.

melita66: (Default)

Re: "Raw cell counts"?

[personal profile] melita66 2023-04-11 11:24 pm (UTC)(link)

Oops! If you look at the extents or coordinates of the raster, you see values like min xy 0,0 to max xy 1000,1000 rather than latitude-longitude or projected coordinates like utm (in Canada x between 200000 and 800000 and y maybe 5000000 to 6000000).