Day/night background issues with polar night about act

[AdamTheisen]

These codes always seem to have issues with high latitude. Thanks for catching this.

[AdamTheisen]

@kenkehoe Where are you getting the lat/lon from, the NAV system?

[kenkehoe]

Hmm, looking into the code a bit I think we are not pulling in the NAV data. The lat/lon are coming from the normal data and at MOS that is set to -9999. In ARM files the missing_value indicator is not being set but there are valid_min/valid_max limits. Let me see what I can do and get back to you. We may need to catch this error in data to say don't plot daylight background.

[AdamTheisen]

I'm having trouble reproducing. I pulled in nav data and it seems to plot all night fine.

[AdamTheisen]

Sounds good @kenkehoe . I'm debating if we want to through an error or just not plot the background when there's no valid lat/lon. Thoughts?

[AdamTheisen]

Something like this perhaps?

if not (-90 <= lat <= 90) or not (-180 <= lon <= 180): raise ValueError(("Lat or Lon are invalid"))

[kenkehoe]

Yeah I think something like that to catch the errors of bad values is all we need. Will need to also check if np.isfinite(lat) == True for cases where there is a missing_value attribute and Xarray converts the value to NaN.

I just added the correct values to the Dataset from NAV and it plotted correctly.

[AdamTheisen]

Added that in along with the finite check to #197