Support CF NetCDF input with lat/lon variable for point2grid

[hsoh-u]

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Describe the Enhancement

point2grid supports two input datasets: GOES16/17 and MET generated point observation data. It would be nice to support NetCDF file with lat/lon variable. There was an request via MET-HELP: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=95225. The other case will be the tri-polar grid work for Lindasy which used python embedding. One issue is finding lat/lon variables if not CF-complaint NetCDF. It be resolved by the configuration.

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3 days

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• METplus, MET, METdb, METviewer, METexpress, METcalcpy, METplotpy

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[hsoh-u]

Fail to read UKMet_tripolar NetCDF (CF Complaint) because "deptht_bounds" was picked as the data variable which does not have the grid information (not related with lat/lon). Need to enhance the logic on picking the data variable.

    float deptht(deptht) ;
            deptht:units = "m" ;
            deptht:long_name = "Vertical T levels" ;
            deptht:bounds = "deptht_bounds" ;
            deptht:positive = "down" ;
            deptht:axis = "Z" ;
    float deptht_bounds(deptht, axis_nbounds) ;
    float nav_lat(y, x) ;
            nav_lat:units = "degrees_north" ;
            nav_lat:long_name = "Latitude" ;
            nav_lat:standard_name = "latitude" ;
            nav_lat:nav_model = "grid_T" ;

...

    float votemper(time_counter, deptht, y, x) ;
            votemper:_FillValue = 1.e+20f ;
            votemper:coordinates = "time_instant deptht nav_lon nav_lat" ;
            votemper:online_operation = "instant" ;
            votemper:interval_write = "1 h" ;
            votemper:cell_methods = "time: point (interval: 60 s)" ;
            votemper:units = "C" ;
            votemper:missing_value = 1.e+20f ;
            votemper:interval_operation = "60 s" ;