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datacarpentry / r-raster-vector-geospatial

Introduction to Geospatial Raster and Vector Data with R
https://datacarpentry.org/r-raster-vector-geospatial
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PROJ string datum warning with rgdal package #364

Closed elk2klein closed 1 year ago

elk2klein commented 2 years ago

The following warning is returned in Introduction to Geospatial Raster and Vector Data with R episodes 13. Create Publication-quality Graphics and 14. Derive Values from Raster Time Series:

Warning in showSRID(SRS_string, format = "PROJ", multiline = "NO", prefer_proj =
prefer_proj): Discarded datum unknown in Proj4 definition

Appears 14 times at start of each episode, and 18 times in answer to the challenge: NDVI for the San Joaquin Experimental Range.. Corresponding data files are 13 tifs in \NEON-DS-Landsat-NDVI\HARV\2011\NDVI and 17 in \NEON-DS-Landsat-NDVI\SJER\2011\NDVI.

Related lesson Rmd files:

Issue #363 is related. See Goodbye PROJ.4! How to specify a coordinate reference system in R?.

Maybe hide the warnings for now by using the following before loading rgdal (via warning when loading rgdal which states to do so): options("rgdal_show_exportToProj4_warnings"="none")

(Disclaimer: I know nothing about rgdal and proj4 vs proj6 and beyond and am just pulling from observations).

srappel commented 2 years ago

Greetings from the Data Carpentry Geospatial Curriculum Advisory Committee (tagging my co-chair @jhollist)

We discussed the transition from PROJ and proj4strings at our Q1 meeting. Here is an excerpt from the minutes.

  1. Transition from PROJ and proj4strings
    • Lessons should be updated to reference coordinate systems by their EPSG codes from the EPSG Geodetic Parameter Dataset instead of using proj4strings. The Committee agreed that the alternative Well-known text (WKT) representation is unwieldy and unnecessary for most common use cases. WKT should be mentioned as an alternative to EPSG codes, especially where there is no existing EPSG standard. Lessons should include examples of converting between the EPSG and WKT representations.

I've added the help wanted tag to this issue in case anyone is interested in helping with this transition away from PROJ4 strings.

Thanks!

drakeasberry commented 1 year ago

Going to close this out as lesson no longer uses rgdal package.