EPSG:9985

COORDINATEOPERATION["NAD83(CSRS)v4 to CGVD28 height (1)",
    VERSION["NRC-Can CGG2000 2002"],
    SOURCECRS[
        GEOGCRS["NAD83(CSRS)v4",
            DATUM["North American Datum of 1983 (CSRS) version 4",
                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",8244]]],
    TARGETCRS[
        VERTCRS["CGVD28 height",
            VDATUM["Canadian Geodetic Vertical Datum of 1928"],
            CS[vertical,1],
                AXIS["gravity-related height (H)",up,
                    LENGTHUNIT["metre",1]],
            ID["EPSG",5713]]],
    METHOD["Geographic3D to GravityRelatedHeight (NRCan byn)",
        ID["EPSG",1060]],
    PARAMETERFILE["Geoid (height correction) model file","HT2_2002v70.byn"],
    OPERATIONACCURACY[0.05],
    USAGE[
        SCOPE["Derivation of gravity-related heights from GNSS observations."],
        AREA["Canada - onshore - Alberta; British Columbia; Manitoba south of 57°N; New Brunswick; Northwest Territories south west of a line between 60°N, 110°W and the coast at 132°W; Nova Scotia; Ontario south of 52°N; Prince Edward Island; Quebec - mainland west of 66°W and south of 55°N; Saskatchewan south of 55°N; Yukon."],
        BBOX[41.67,-141.01,69.8,-59.73]],
    ID["EPSG",9985],
    REMARK["Valid at epoch 2002.0. Hybrid geoid model, grid derived at epoch 1997.0 through NAD83(CSRS)v3 (CT code 9983) and then modified to include correction for propagation of height between 1997.0 and 2002.0 derived from the Canada velocity grid v7.0."]]

proj4.defs("EPSG:9985","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=ca_nrc_HT2_2002v70.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": "NAD83(CSRS)v4 to CGVD28 height (1)",
    "source_crs": {
        "type": "GeographicCRS",
        "name": "NAD83(CSRS)v4",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "North American Datum of 1983 (CSRS) version 4",
            "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": 8244
        }
    },
    "target_crs": {
        "type": "VerticalCRS",
        "name": "CGVD28 height",
        "datum": {
            "type": "VerticalReferenceFrame",
            "name": "Canadian Geodetic Vertical Datum of 1928"
        },
        "coordinate_system": {
            "subtype": "vertical",
            "axis": [
                {
                    "name": "Gravity-related height",
                    "abbreviation": "H",
                    "direction": "up",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 5713
        }
    },
    "method": {
        "name": "Geographic3D to GravityRelatedHeight (NRCan byn)",
        "id": {
            "authority": "EPSG",
            "code": 1060
        }
    },
    "parameters": [
        {
            "name": "Geoid (height correction) model file",
            "value": "HT2_2002v70.byn",
            "id": {
                "authority": "EPSG",
                "code": 8666
            }
        }
    ],
    "accuracy": "0.05",
    "scope": "Derivation of gravity-related heights from GNSS observations.",
    "area": "Canada - onshore - Alberta; British Columbia; Manitoba south of 57°N; New Brunswick; Northwest Territories south west of a line between 60°N, 110°W and the coast at 132°W; Nova Scotia; Ontario south of 52°N; Prince Edward Island; Quebec - mainland west of 66°W and south of 55°N; Saskatchewan south of 55°N; Yukon.",
    "bbox": {
        "south_latitude": 41.67,
        "west_longitude": -141.01,
        "north_latitude": 69.8,
        "east_longitude": -59.73
    },
    "id": {
        "authority": "EPSG",
        "code": 9985
    },
    "remarks": "Valid at epoch 2002.0. Hybrid geoid model, grid derived at epoch 1997.0 through NAD83(CSRS)v3 (CT code 9983) and then modified to include correction for propagation of height between 1997.0 and 2002.0 derived from the Canada velocity grid v7.0."
}

<?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=ca_nrc_HT2_2002v70.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=ca_nrc_HT2_2002v70.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 ( 9985, 'EPSG', 9985, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=ca_nrc_HT2_2002v70.tif +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');