[ferret_users] Transforming a non-standard-convention netCDF file

[Anton Yoel Buenavista <tmsbayd@xxxxxxxxxx>]

Greetings to everyone,

Does Ferret have any facilities to transform a non-standard-convention (i.e. non-CF) gridded netcdf file into a CF-convention one? We'd like to do this so that the files can be easily managed by LAS or other netcdf-friendly software. Specific details below.

Our netCDF file in question does not use lon,lat axes but a rectangular Cartesian grid.  However, each grid point is indexed to a lon,lat coordinate.  To illustrate, the "ncdump -h" of the netCDF file is at the bottom of this e-mail.

When we plot the netCDF file we get the plot as seen on Figure A below, where the North is not vertically upwards.  We'd like to transform this into a regular lon-lat grid.


Fig. A

Any pointers would be most appreciated.

--------- start ncdump -h ---------------
netcdf hydro_avged_2D {
dimensions:
    time = UNLIMITED ; // (84 currently)
    xaxis = 1320 ;
    yaxis = 1482 ;
    zaxis = 1 ;
variables:
    double time(time) ;
        time:long_name = "coordinate variables of time" ;
        time:units = "second since 2008-01-22" ;
        time:figure = "na" ;
    float h(yaxis, xaxis) ;
        h:long_name = "distance from still water level to sea bed" ;
        h:units = "meter" ;
        h:figure = "scalar_h" ;
        h:_FillValue = 9.96921e+36f ;
    float lon(yaxis, xaxis) ;
        lon:long_name = "longitude(east)" ;
        lon:units = "degrees_east" ;
        lon:figure = "na" ;
        lon:_FillValue = 9.96921e+36f ;
    float lat(yaxis, xaxis) ;
        lat:long_name = "latitude(north)" ;
        lat:units = "degrees_north" ;
        lat:figure = "na" ;
        lat:_FillValue = 9.96921e+36f ;
    float mask(yaxis, xaxis) ;
        mask:long_name = "computational mask. 1 is a computational cell, 0 is a land cell." ;
        mask:units = "none" ;
        mask:figure = "mask" ;
        mask:_FillValue = 9.96921e+36f ;
    float e(time, yaxis, xaxis) ;
        e:long_name = "water surface elevation from still water level" ;
        e:units = "meter" ;
        e:figure = "scalar" ;
        e:_FillValue = 9.96921e+36f ;
    float va(time, yaxis, xaxis) ;
        va:long_name = "depth averaged current speed along y-axis" ;
        va:units = "meter/second" ;
        va:figure = "vector_y" ;
        va:_FillValue = 9.96921e+36f ;
    float ua(time, yaxis, xaxis) ;
        ua:long_name = "depth averaged water current speed along x-axis" ;
        ua:units = "meter/second" ;
        ua:figure = "vector_x" ;
        ua:_FillValue = 9.96921e+36f ;

}
--------- end ncdump -h ---------------

-- 
Regards,
Anton Yoel Buenavista