Geodetic CRS: DrukRef23
Datum: National Reference Frame of Bhutan 2023
Ellipsoid: GRS 1980
Prime meridian: Greenwich
Data source: EPSG
Information source: MIRASpaco on behalf of NLCS (National Land Commission Secretariat of Bhutan); https://miranet.nlcs.gov.bt/public/geoid/
Revision date: 2026-02-27
Scope: Derivation of gravity-related heights from GNSS observations.
Remarks: The DrukGeoid22 geoid separation model defines Bhutan Vertical Datum 2022 heights. For reversible alternative to this transformation see DrukRef23 to DrukRef23 + Bhutan Vertical Datum 2022 height (1) (code 11384).
Method: Geographic3D to GravityRelatedHeight (gtx)
Area of use: Bhutan.
Description: (0,)
Definition: OGC Well Known Text 2 (2019)
COORDINATEOPERATION["DrukRef23 to Bhutan Vertical Datum 2022 height (1)", VERSION["NLCS-Btn 2022"], SOURCECRS[ GEOGCRS["DrukRef23", DATUM["National Reference Frame of Bhutan 2023", 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",11225]]], TARGETCRS[ VERTCRS["Bhutan Vertical Datum 2022 height", VDATUM["Bhutan Vertical Datum 2022"], CS[vertical,1], AXIS["gravity-related height (H)",up, LENGTHUNIT["metre",1]], ID["EPSG",11338]]], METHOD["Geographic3D to GravityRelatedHeight (gtx)", ID["EPSG",9665]], PARAMETERFILE["Geoid (height correction) model file","drukgeoid2022.gtx"], OPERATIONACCURACY[0.1], USAGE[ SCOPE["Derivation of gravity-related heights from GNSS observations."], AREA["Bhutan."], BBOX[26.7,88.74,28.33,92.13]], ID["EPSG",11339], REMARK["The DrukGeoid22 geoid separation model defines Bhutan Vertical Datum 2022 heights. For reversible alternative to this transformation see DrukRef23 to DrukRef23 + Bhutan Vertical Datum 2022 height (1) (code 11384)."]]
Definition: JavaScript (Proj4js)
proj4.defs("EPSG:11339","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=drukgeoid2022.gtx +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1");
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "Transformation", "name": "DrukRef23 to Bhutan Vertical Datum 2022 height (1)", "source_crs": { "type": "GeographicCRS", "name": "DrukRef23", "datum": { "type": "GeodeticReferenceFrame", "name": "National Reference Frame of Bhutan 2023", "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": 11225 }, "remarks": "Replaces DRUKREF 03 (CRS code 5263)." }, "target_crs": { "type": "VerticalCRS", "name": "Bhutan Vertical Datum 2022 height", "datum": { "type": "VerticalReferenceFrame", "name": "Bhutan Vertical Datum 2022" }, "coordinate_system": { "subtype": "vertical", "axis": [ { "name": "Gravity-related height", "abbreviation": "H", "direction": "up", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 11338 } }, "method": { "name": "Geographic3D to GravityRelatedHeight (gtx)", "id": { "authority": "EPSG", "code": 9665 } }, "parameters": [ { "name": "Geoid (height correction) model file", "value": "drukgeoid2022.gtx", "id": { "authority": "EPSG", "code": 8666 } } ], "accuracy": "0.1", "scope": "Derivation of gravity-related heights from GNSS observations.", "area": "Bhutan.", "bbox": { "south_latitude": 26.7, "west_longitude": 88.74, "north_latitude": 28.33, "east_longitude": 92.13 }, "id": { "authority": "EPSG", "code": 11339 }, "remarks": "The DrukGeoid22 geoid separation model defines Bhutan Vertical Datum 2022 heights. For reversible alternative to this transformation see DrukRef23 to DrukRef23 + Bhutan Vertical Datum 2022 height (1) (code 11384)." }
Definition: MapServer - MAPfile
PROJECTION "proj=pipeline" "step" "proj=axisswap" "order=2,1" "step" "proj=unitconvert" "xy_in=deg" "xy_out=rad" "step" "inv" "proj=vgridshift" "grids=drukgeoid2022.gtx" "multiplier=1" "step" "proj=unitconvert" "xy_in=rad" "xy_out=deg" "step" "proj=axisswap" "order=2,1" END
Definition: Mapnik
<?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=drukgeoid2022.gtx +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=drukgeoid2022.gtx +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1"> </Layer> </Map>
Definition: SQL (PostGIS)
INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 11339, 'EPSG', 11339, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=vgridshift +grids=drukgeoid2022.gtx +multiplier=1 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');