Change coordinate in file DFSU to NetCDF

[minhmminh0419-lgtm]

I have a DFSU file whose coordinates are in WGS84 / UTM Zone 48N, but I don’t know how to convert them to longitude and latitude. I tried using PyProj in Python but it didn’t work. Could you please offer some advice? Thanks in advance!

Here is my code:

import xarray as xr
import numpy as np
from pyproj import Transformer

ds = xr.open_dataset("tide_u.nc")

x = ds["x"].values # shape (nx,)
y = ds["y"].values # shape (ny,)

if x.ndim == 1 and y.ndim == 1:
xx, yy = np.meshgrid(x, y) # (ny, nx)
else:
xx, yy = x, y

transformer = Transformer.from_crs("EPSG:32648", "EPSG:4326", always_xy=True)
lon2d, lat2d = transformer.transform(xx, yy)

ds = ds.assign_coords({
"lon": (("y","x"), lon2d),
"lat": (("y","x"), lat2d)
})

ds = ds.rename_dims({"x": "longitude", "y": "latitude"})

ds = ds.assign_coords({
"latitude": (("latitude", "longitude"), lat2d),
"longitude": (("latitude", "longitude"), lon2d),
})

outfile = "u_lonlat.nc"
ds.to_netcdf(outfile)

[jsmariegaard]

@daniel-caichac-DHI could you guide @minhmminh0419-lgtm a bit here?