EPSG:7840

COORDINATEOPERATION["NZGD2000 to NZVD2016 height (1)",
    VERSION["LINZ-NZ 2016"],
    SOURCECRS[
        GEOGCRS["NZGD2000",
            DATUM["New Zealand Geodetic Datum 2000",
                ELLIPSOID["GRS 1980",6378137,298.257222101,
                    LENGTHUNIT["metre",1]]],
            PRIMEM["Greenwich",0,
                ANGLEUNIT["degree",0.0174532925199433]],
            CS[ellipsoidal,3],
                AXIS["geodetic latitude (Lat)",north,
                    ORDER[1],
                    ANGLEUNIT["degree",0.0174532925199433]],
                AXIS["geodetic longitude (Lon)",east,
                    ORDER[2],
                    ANGLEUNIT["degree",0.0174532925199433]],
                AXIS["ellipsoidal height (h)",up,
                    ORDER[3],
                    LENGTHUNIT["metre",1]],
            ID["EPSG",4959]]],
    TARGETCRS[
        VERTCRS["NZVD2016 height",
            VDATUM["New Zealand Vertical Datum 2016"],
            CS[vertical,1],
                AXIS["gravity-related height (H)",up,
                    LENGTHUNIT["metre",1]],
            ID["EPSG",7839]]],
    METHOD["Geographic3D to GravityRelatedHeight (NZgeoid)",
        ID["EPSG",1030]],
    PARAMETERFILE["Geoid (height correction) model file","New_Zealand_Quasigeoid_2016.csv"],
    OPERATIONACCURACY[0.1],
    USAGE[
        SCOPE["Derivation of gravity-related heights from GNSS observations."],
        AREA["New Zealand - onshore and offshore. Includes Antipodes Islands, Auckland Islands, Bounty Islands, Chatham Islands, Cambell Island, Kermadec Islands, Raoul Island and Snares Islands."],
        BBOX[-55.95,160.6,-25.88,-171.2]],
    ID["EPSG",7840],
    REMARK["Defines NZVD2016 vertical datum (datum code 1169, CRS code 7839)."]]

proj4.defs("EPSG:7840","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=nz_linz_nzgeoid2016.tif +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1");

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "Transformation",
    "name": "NZGD2000 to NZVD2016 height (1)",
    "source_crs": {
        "type": "GeographicCRS",
        "name": "NZGD2000",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "New Zealand Geodetic Datum 2000",
            "ellipsoid": {
                "name": "GRS 1980",
                "semi_major_axis": 6378137,
                "inverse_flattening": 298.257222101
            }
        },
        "coordinate_system": {
            "subtype": "ellipsoidal",
            "axis": [
                {
                    "name": "Geodetic latitude",
                    "abbreviation": "Lat",
                    "direction": "north",
                    "unit": "degree"
                },
                {
                    "name": "Geodetic longitude",
                    "abbreviation": "Lon",
                    "direction": "east",
                    "unit": "degree"
                },
                {
                    "name": "Ellipsoidal height",
                    "abbreviation": "h",
                    "direction": "up",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 4959
        }
    },
    "target_crs": {
        "type": "VerticalCRS",
        "name": "NZVD2016 height",
        "datum": {
            "type": "VerticalReferenceFrame",
            "name": "New Zealand Vertical Datum 2016"
        },
        "coordinate_system": {
            "subtype": "vertical",
            "axis": [
                {
                    "name": "Gravity-related height",
                    "abbreviation": "H",
                    "direction": "up",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 7839
        }
    },
    "method": {
        "name": "Geographic3D to GravityRelatedHeight (NZgeoid)",
        "id": {
            "authority": "EPSG",
            "code": 1030
        }
    },
    "parameters": [
        {
            "name": "Geoid (height correction) model file",
            "value": "New_Zealand_Quasigeoid_2016.csv",
            "id": {
                "authority": "EPSG",
                "code": 8666
            }
        }
    ],
    "accuracy": "0.1",
    "scope": "Derivation of gravity-related heights from GNSS observations.",
    "area": "New Zealand - onshore and offshore. Includes Antipodes Islands, Auckland Islands, Bounty Islands, Chatham Islands, Cambell Island, Kermadec Islands, Raoul Island and Snares Islands.",
    "bbox": {
        "south_latitude": -55.95,
        "west_longitude": 160.6,
        "north_latitude": -25.88,
        "east_longitude": -171.2
    },
    "id": {
        "authority": "EPSG",
        "code": 7840
    },
    "remarks": "Defines NZVD2016 vertical datum (datum code 1169, CRS code 7839)."
}

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=nz_linz_nzgeoid2016.tif +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1">
	<Layer srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=nz_linz_nzgeoid2016.tif +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1">
	</Layer>
</Map>

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 7840, 'EPSG', 7840, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=nz_linz_nzgeoid2016.tif +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');