Change of height to a different vertical reference surface and unit.
(0,)
Definition: OGC Well Known Text 2 (2019)
CONCATENATEDOPERATION["NGVD29 height (ftUS) to NAVD88 height (3)", VERSION["IOGP - US Conus E"], SOURCECRS[ VERTCRS["NGVD29 height (ftUS)", VDATUM["National Geodetic Vertical Datum 1929"], CS[vertical,1], AXIS["gravity-related height (H)",up, LENGTHUNIT["US survey foot",0.304800609601219]], ID["EPSG",5702]]], TARGETCRS[ VERTCRS["NAVD88 height", VDATUM["North American Vertical Datum 1988"], CS[vertical,1], AXIS["gravity-related height (H)",up, LENGTHUNIT["metre",1]], ID["EPSG",5703]]], STEP[ CONVERSION["Vertical Axis Unit Conversion", METHOD["Change of Vertical Unit", ID["EPSG",1104]], ID["EPSG",7813]]], STEP[ COORDINATEOPERATION["NGVD29 height (m) to NAVD88 height (3)", VERSION["NGS-US Conus E"], SOURCECRS[ VERTCRS["NGVD29 height (m)", VDATUM["National Geodetic Vertical Datum 1929"], CS[vertical,1], AXIS["gravity-related height (H)",up, LENGTHUNIT["metre",1]], ID["EPSG",7968]]], TARGETCRS[ VERTCRS["NAVD88 height", VDATUM["North American Vertical Datum 1988"], CS[vertical,1], AXIS["gravity-related height (H)",up, LENGTHUNIT["metre",1]], ID["EPSG",5703]]], METHOD["Vertical Offset by Grid Interpolation (VERTCON)", ID["EPSG",9658]], PARAMETERFILE["Vertical offset file","vertcone.94"], OPERATIONACCURACY[0.02], ID["EPSG",7971], REMARK["In this area the NGVD29 vertical reference surface is approximately 0 to 0.5m above the NAVD88 surface. Interpolation within the gridded data file may be made using either NAD27 or any of the realisations of NAD83 applicable to US conus."]]], OPERATIONACCURACY[0.02], USAGE[ SCOPE["Change of height to a different vertical reference surface and unit."], AREA["United States (USA) - CONUS east of 89°W - onshore - Alabama; Connecticut; Delaware; Florida; Georgia; llinois; Indiana; Kentucky; Maine; Maryland; Massachusetts; Michigan; Mississippi; New Hampshire; New Jersey; New York; North Carolina; Ohio; Pennsylvania; Rhode Island; South Carolina; Tennessee; Vermont; Virginia; West Virginia; Wisconsin."], BBOX[24.41,-89,48.32,-66.91]], ID["EPSG",7975]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "ConcatenatedOperation", "name": "NGVD29 height (ftUS) to NAVD88 height (3)", "source_crs": { "type": "VerticalCRS", "name": "NGVD29 height (ftUS)", "datum": { "type": "VerticalReferenceFrame", "name": "National Geodetic Vertical Datum 1929" }, "coordinate_system": { "subtype": "vertical", "axis": [ { "name": "Gravity-related height", "abbreviation": "H", "direction": "up", "unit": { "type": "LinearUnit", "name": "US survey foot", "conversion_factor": 0.304800609601219 } } ] }, "id": { "authority": "EPSG", "code": 5702 } }, "target_crs": { "type": "VerticalCRS", "name": "NAVD88 height", "datum": { "type": "VerticalReferenceFrame", "name": "North American Vertical Datum 1988" }, "coordinate_system": { "subtype": "vertical", "axis": [ { "name": "Gravity-related height", "abbreviation": "H", "direction": "up", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 5703 } }, "steps": [ { "type": "Conversion", "name": "Vertical Axis Unit Conversion", "method": { "name": "Change of Vertical Unit", "id": { "authority": "EPSG", "code": 1104 } }, "id": { "authority": "EPSG", "code": 7813 } }, { "type": "Transformation", "name": "NGVD29 height (m) to NAVD88 height (3)", "source_crs": { "type": "VerticalCRS", "name": "NGVD29 height (m)", "datum": { "type": "VerticalReferenceFrame", "name": "National Geodetic Vertical Datum 1929" }, "coordinate_system": { "subtype": "vertical", "axis": [ { "name": "Gravity-related height", "abbreviation": "H", "direction": "up", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 7968 } }, "target_crs": { "type": "VerticalCRS", "name": "NAVD88 height", "datum": { "type": "VerticalReferenceFrame", "name": "North American Vertical Datum 1988" }, "coordinate_system": { "subtype": "vertical", "axis": [ { "name": "Gravity-related height", "abbreviation": "H", "direction": "up", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 5703 } }, "method": { "name": "Vertical Offset by Grid Interpolation (VERTCON)", "id": { "authority": "EPSG", "code": 9658 } }, "parameters": [ { "name": "Vertical offset file", "value": "vertcone.94", "id": { "authority": "EPSG", "code": 8732 } } ], "accuracy": "0.02", "id": { "authority": "EPSG", "code": 7971 }, "remarks": "In this area the NGVD29 vertical reference surface is approximately 0 to 0.5m above the NAVD88 surface. Interpolation within the gridded data file may be made using either NAD27 or any of the realisations of NAD83 applicable to US conus." } ], "accuracy": "0.02", "scope": "Change of height to a different vertical reference surface and unit.", "area": "United States (USA) - CONUS east of 89°W - onshore - Alabama; Connecticut; Delaware; Florida; Georgia; llinois; Indiana; Kentucky; Maine; Maryland; Massachusetts; Michigan; Mississippi; New Hampshire; New Jersey; New York; North Carolina; Ohio; Pennsylvania; Rhode Island; South Carolina; Tennessee; Vermont; Virginia; West Virginia; Wisconsin.", "bbox": { "south_latitude": 24.41, "west_longitude": -89, "north_latitude": 48.32, "east_longitude": -66.91 }, "id": { "authority": "EPSG", "code": 7975 } }
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=pipeline +step +proj=unitconvert +z_in=us-ft +z_out=m +step +proj=vgridshift +grids=us_noaa_vertcone.tif +multiplier=1"> <Layer srs="+proj=pipeline +step +proj=unitconvert +z_in=us-ft +z_out=m +step +proj=vgridshift +grids=us_noaa_vertcone.tif +multiplier=1"> </Layer> </Map>
Definition: SQL (PostGIS)
INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 7975, 'EPSG', 7975, '+proj=pipeline +step +proj=unitconvert +z_in=us-ft +z_out=m +step +proj=vgridshift +grids=us_noaa_vertcone.tif +multiplier=1', 'None');