Hello! I would like to ask some questions about OBSGRID.
Question 1: According to the official user guide I've read, it says that the observation data has a time interval of 6 hours and after downloading, it needs to be split into 3-hour intervals using get_rda_data.exe. Is this a necessary step? If I use the WPS to generate met_em.* files based on 6-hour ERA5 data, do I still need to split the OBS data into 3-hour intervals when processing the met_em.* files with OBSGRID?
Here is a screenshot of the official user guide:

Question 2: If I need to modify the data splitting interval of the get_rda_data.exe program, should I modify the get_rda_data.f file and recompile it, or should I directly modify the interval value in the record1 section of the namelist.oa?
These are my questions, and I look forward to your answers!
Question 1: According to the official user guide I've read, it says that the observation data has a time interval of 6 hours and after downloading, it needs to be split into 3-hour intervals using get_rda_data.exe. Is this a necessary step? If I use the WPS to generate met_em.* files based on 6-hour ERA5 data, do I still need to split the OBS data into 3-hour intervals when processing the met_em.* files with OBSGRID?
Here is a screenshot of the official user guide:

Question 2: If I need to modify the data splitting interval of the get_rda_data.exe program, should I modify the get_rda_data.f file and recompile it, or should I directly modify the interval value in the record1 section of the namelist.oa?
These are my questions, and I look forward to your answers!