r-raster-vector-geospatial
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datacarpentry
issue in lesson one - units
Currently there is a comment about the raster image that asks the user whether the units are in meters or feet using the CRS. this is a trick question because the units are not actually indicated (nor would they be) in the crs in this instance. Need to fix this!
http://neondataskills.org/R/Introduction-to-Raster-Data-In-R/#comment-3024003521
There are several sections of this lesson that need to be updated/changed to reflect this.
- End of 2nd paragraph in Types of Data Stored... section
- Question after first plot in the Open a Raster in R section
- Add content/change meter indication in the Raster Min/Max section
Also, the rest of the series makes the assumption that the raster values are meters so we need to establish how the users would know this in this tutorial.
Does NEON have metadata for the geotiffs (not in the tif tags but an actual file)? If they do, it will resolve it all.
Otherwise, we will need to state it is in meters – I can write a paragraph about how units are often standard for Elevation Models (ie meters horizontal and vertical) but not always (ie state plane feet with vert in meters, etc). This was the issue when we started the lessons – no metadata and difficult to access tif tags (not standardized / accessible via rGDAL, etc).
I have an email out asking this right now. I'll update this thread when I get an answer. I think a paragraph specifically stating at the horizontal units (CRS) don't translate to vertical units (raster values) would be a good addition to the tutorial either way.
@lwasser I think this issue has been addressed now. See screenshot:
Can this be closed?
Erin – this issue may still be outstanding. The units that you see in that image are the HORIZONTAL – x and y units. However I think in the text it talks about the VERTICAL units. Ie the elevation presented in the raster. I’m not logged in to be more specific now but I think someone should check this out to ensure the language has been fixed. You can NOT determine the vertical units without referencing the metadata is the solution. +m is just horizontal not vertical
@datacarpentry/geospatial-maintainers - can one of the Maintainers assign this issue to themselves and check out the units issue before our lesson release (currently scheduled for mid-July)?
Any feedback from the Maintainers (@jsta @obrl-soil @r4space) on this issue? Does it need to be resolved before our publication or can it wait?
My feeling is that we can include a note about checking vertical resolution in the organization-geospatial repo rather than here.
