Radar frequency and pyart.retrieve

[jlpippitt]

Functions within pyart.retrieve grab frequency data from radar.instrument_parameters["frequency"]["data"][0]. If parameter does not exsist then equations are set to C band. The problem, S band IRIS radars (NPOL, KPOL) do not contain radar.instrument_parameters["frequency"] information, therefor incorrect equations are applied.

We used our old rsl_in_idl software and found frequency is in the ray header.
radar.volume.sweep.ray.h
FREQUENCY FLOAT 2.80968

Can pyART pull frequency from ray header and add radar.instrument_parameters["frequency"] to radar.info() for IRIS radars?

Thank you.

[mgrover1]

@jlpippitt - thanks for raising this issue - this would need to be done at the IO level, or you could pass that information through depending on which retrieval you are using. What part of pyart.retrieve are you using?

[jlpippitt]

Raw IRIS NPOL file.

You can download any file from link.
https://pmm-gv.gsfc.nasa.gov/pub/NPOL/Newark/2024/0228/ppi/

Thank you.

[jlpippitt]

@mgrover1 - Just a follow up, has the issue been addressed?

Thank you.

[mgrover1]

Not yet - I apologize for the delay here

[mgrover1]

@jlpippitt - I looked into this a bit, and we have the parameter needed to calculate frequency - wavelength! I just added a PR adding this as a calculated field on IO

#1557

NumPy has a utility function for converting wavelength to frequency we can use! I tested it on the file you provided, and it worked as expected! We will ensure this is reviewed and merged.

[jlpippitt]

It works, thank you!