Missing platform motion variables

[jcdehart]

Package/OS Details

• pyart: 1.16.1 and 2.0.1
• python: 3.12
• OS: Linux (not sure of details as its our supercomputer)
• note: issue was duplicated by @rcjackson on his system

Issue

We needed to correct the Doppler velocity for platform motion, but we noticed that the platform motion variables/metadata were not visible in the radar object (using vars(radar)). I tried loading the file with both pyart.io.read_cfradial(file) and pyart.io.read(file).

The variables in question are shown in the ncdump screenshot below, but are eastward_velocity, northward_velocity, vertical_velocity, heading_change_rate, and pitch_change_rate. I admit I don't know whether these conform to standard variable naming conventions for these fields, but I was surprised to not see them in the object at all and thus not written to the output file at the end of my code.

Let me know if any other information is required and I'm happy to share a sample file through google drive.

Thanks!
Jen

[zssherman]

Hi @jcdehart, Thanks for raising the issue! I do not see those variable names in Py-ART's default config. Either they were never added or weren't added due to not conforming to standards (this one im not sure, maybe they are standard and were just missed). When reading in the file, if you set file_field_names to True it should hopefully show those variables for now.

[zssherman]

@jcdehart I did find those variables in the cfradial documentation. I'll add those into Py-ART

[zssherman]

Nvm I found it in an old 2018 document, but can't seem to find it in the cfradial standard name url last updated in March https://cfconventions.org/Data/cf-standard-names/current/build/cf-standard-name-table.html

[zssherman]

@mgrover1 Do we know if these are old standard names?

[jcdehart]

I reached out to Mike Dixon who provided an updated CfRadial document from 2021, which shows the three platform motion variables (eastward, northward, vertical...) in Section 5.6.

He doesn't think there are standard names for heading_change_rate and pitch_change_rate, so I'll reach out to Michael Bell and the SEAPOL team to see if they had a reference for giving those variables those names.

CfRadialDoc.v1.5.20211201 (1).pdf

[zssherman]

@jcdehart Thanks for reaching out to them! I'll add a PR with the current variables in the 2021 document you shared. I can add the others once Michael Bell responds.

[zssherman]

I'm going to reopen this, I closed on accident as we are still waiting to hear back on some of the missing variables.