Editing Lat and Lon Values in cfRadial file

[GGDLW]

Hello, I noticed that when I open a couple of cfRadial files I have, the latitude and longitude arrays are filled with missing values (they would display as --,-- when I printed them). I was wondering if there was a way to edit said file to insert the correct coordinates into the cfRadial file with the missing data.

[zssherman]

Hi @GGDLW , you would want to set the radar.latitude and longitude and recalculate the arrays. You can do this by:

radar.latitude["data"] = np.array([your_latitude])
radar.longitude["data"] = np.array([your_longitude]])

radar.init_gate_altitude()
radar.init_gate_longitude_latitude()

[GGDLW]

This worked like a charm!

[GGDLW]

My next issue would be after I edit such, it would raise the following error when I called the column_profile method I used from one of the example plots.
Traceback (most recent call last): ...... raise ValueError("index must be monotonic increasing or decreasing") ValueError: index must be monotonic increasing or decreasing

Do i need to do something to these arrays before I use the column_profile method?

[zssherman]

@GGDLW Which line of the column profile is throwing that error?

[GGDLW]

It's the last line where: return col_prof.interp_like(new_heights)

[zssherman]

@GGDLW Can you share what your parameters are for the column profile code? Trying to see what can cause the issue. Also @jrobrien91 have you seen this error before with the column code before?

[GGDLW]

col_prof_interp = column_profile(radar,latitude=41.05,longitude=-97.12, azimuth_spread=3,spatial_spread=3,v_res=100, min_alt=200, max_alt=3000)

[GGDLW]

I was running this method in a for loop with about 6-hours of radar files, and it was working for most of the files I've had in the list that were processed by the for loop.

[zssherman]

Ah gotcha, could be how the heights or coordinates are stored in the xarray dataset for those specific files. In that example if your able to compare the heights between a working an non working file, we might be able to pinpoint the issue.

[GGDLW]

This is all very helpful! I've also found that my latitude and longitude arrays were different lengths when changing from file to file. I was trying to use a sample file which had a lat and lon array shaped different compared to the non-working file. Thank you so much for your assistance!

[zssherman]

Or we might have to use assume_sorted parameter for interp_like

[jrobrien91]

@GGDLW @zssherman - check this out: https://arm-development.github.io/bnf-radar-examples/bnf-radclss/

This is how we are making daily columns similar to your use case.

I suspect the "monotonic increasing or decreasing" ValueError is due to not having equally spaced height gates when attempting to concatenate across a day.

By default, the CVP function returns the heights of the gates for that specific profile, which can change during the day due to environmental conditions.

I interpolate each height profile to a standard profile when running the CVP across the day.

If some files are failing, I suspect there may be different scans embedded.
Check out including columns from RHI scans here: https://arm-development.github.io/bnf-radar-examples/bnf-sacr-rhi/