RadxMergeVols to merge sweep scans

Hi,

I have a list of files as follows: each contains one sweep (elevation angle) of PPI scan. I aim to merge them into one volume scan cfradial file with RadxMergeVols.

‘’’

cfrad.20181205_192446.158_to_20181205_192504.350_COW1low_SUR.nc
cfrad.20181205_192504.375_to_20181205_192522.355_COW1low_SUR.nc
cfrad.20181205_192522.380_to_20181205_192540.360_COW1low_SUR.nc

cfrad.20181205_192822.430_to_20181205_192840.412_COW1low_SUR.nc
cfrad.20181205_192840.438_to_20181205_192858.418_COW1low_SUR.nc

‘’’

However, I’m not sure how to set up the params file. I was supposed to set “merge_method = MERGE_SERIAL;” but it didn’t work (not sure what to set in “serial_vol_types”). And for “merge_method = MERGE_PARALLEL;” it only works with 2 sweeps.

My question is, for a case like this, how to set the params file to merge each sweep scan into one file?

Thanks for your help!