Problem 1, _FillValue

1) ncdump HWX_2020_02_10_07_04_44.nc > 1.txt

2) open in you favorite editor 1.txt

3) view the data: DBZ you will see 0's in the data

4) go up to the variables: find the DBZ , change the _fillValue = -9999.f  to _FillValue 0.0f, save the changes

5) ncgen3 -o HWX.nc 1.txt

6) ncdump HWX.nc > 2.txt

7) open in an editor 2.txt and look at the data: DBZ the 0's should be dashes

8) for fun you can open both *.nc files using  "2-plot-mmr.py plot"

 

also cfradial1.3 manual page 65 you will see the _FillValue in the example

 

Problem 2

the data: nyquist_velocity is bad again view one of the *.txt files from above and look at the nyquist_velocity and velocity