coastalmodeling-vdatum

To support costal modelers with vertical datum conversion.
Conversions between the following datums are suported: xgeoid20b, navd88, mllw, and lmsl.

Installation

conda create --name cmvd python=3.11
conda activate cmvd
pip install "git+https://github.com/oceanmodeling/coastalmodeling-vdatum.git"

Usage Examples:

Vertical Datum Conversion

The package can be used as:

from coastalmodeling_vdatum import vdatum

x,y,z = vdatum.convert(vd_from, vd_to, lat, lon , z, online=True, epoch=None)

Compute Node (offline) Applications

coastalmodeling-vdatum can be used offline (no aws connection) by changing the pre-defined geotiff file paths to a local directory (the geotiff files can be downloaded from here):

from coastalmodeling_vdatum import vdatum, _path

_path.NAVD88_G2018=f"{PATH}/us_noaa_g2018u0.tif"
_path.XGEOID20B=f"{PATH}/xGEOID20B.tif"
_path.MLLW_ITRF2020_2020=f"{PATH}/us_noaa_nos_MLLW-ITRF2020_2020.0_nwldatum_4.7.0_20240621_.tif"
_path.LMSL_ITRF2020_2020f"{PATH}/us_noaa_nos_LMSL-ITRF2020_2020.0_nwldatum_4.7.0_20240621_.tif"

x,y,z = vdatum.convert(vd_from, vd_to, lat, lon , z, online=False, epoch=None)

Mesh Vertical Datum Conversion (SCHISM-OCSMesh)

coastalmodeling-vdatum can be used update mesh bathymetry via OCSMesh.

from coastalmodeling_vdatum import vdatum
import ocsmesh
import numpy as np

gd = ocsmesh.Mesh.open(HGRID_PATH, crs=4326)

x,y,z = vdatum.convert(vd_from, vd_to, gd.vert2['coord'][:, -1], gd.vert2['coord'][:, 0] , gd.value, online=True, epoch=None)
z[np.isinf(z)] = gd.value[np.isinf(z)]

mesh_msht = ocsmesh.utils.msht_from_numpy(
        coordinates=gd.vert2['coord'],
        triangles=gd.tria3['index'],
        quadrilaterals=gd.quad4['index'] if len(gd.quad4['index']) > 0 else None,
        crs=4326
    )

mesh_msht.value= np.array(z)

ocsmesh.Mesh(mesh_msht).write({PATH_OUT}/mesh.2dm, format='2dm', overwrite=True)

Mesh Vertical Datum Conversion (SCHISM-pylibs)

coastalmodeling-vdatum can be used update mesh bathymetry via pylibs.

from coastalmodeling_vdatum import vdatum
from pylib import schism_grid as read_hgrid

gd = read_hgrid(HGRID_PATH)

x,y,z = vdatum.convert(vd_from, vd_to, gd.y, gd.x , gd.z, online=True, epoch=None)
z[np.isinf(z)] = gd.z[np.isinf(z)]
gd.dp=z

gd.write_hgrid({PATH_OUT}/mesh.gr3')