I have data with this spatial reference in proj4 format:
+proj=eqc +lat_ts=8 +lat_0=0 +lon_0=180 +x_0=0 +y_0=0 +a=1737400 +b=1737400 +units=m +no_def
As I understand it, +proj=eqc is the Plate Carree (equidistant cylindrical) as described here.
However, that doesn't take a lat_ts parameter (latitude at true scale). Can anyone explain why, and how I can express this coordinate system in cartopy?
You can't currently express that parameter for Equidistant Cyclindrical in Cartopy. The PlateCarree projection in CartoPy has some weird behavior as well. If this is important to you, I'd suggest opening an issue, or better yet, contributing a Pull Request to add Equidistant Cylindrical as a proper projection to CartoPy.