Transformation of coordinates at 0.02m level of accuracy.
Interpolation within the gridded data file may be made using any of the horizontal CRSs NAD27, NAD83 or NAD83(HARN).
Vertical Offset by Grid Interpolation (VERTCON)
(0,)
Definition: OGC Well Known Text 2 (2019)
COORDINATEOPERATION["NGVD29 height to NAVD88 height (1)", VERSION["NGS-US Conus W"], 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]]], METHOD["Vertical Offset by Grid Interpolation (VERTCON)", ID["EPSG",9658]], PARAMETERFILE["Vertical offset file","vertconw.94"], OPERATIONACCURACY[0.02], USAGE[ SCOPE["Transformation of coordinates at 0.02m level of accuracy."], AREA["United States (USA) - CONUS west of 107°W - onshore - Arizona; California; Colorado; Idaho; Montana; Nevada; New Mexico; Oregon; Utah; Washington; Wyoming."], BBOX[31.33,-124.79,49.05,-107]], ID["EPSG",5409], REMARK["Interpolation within the gridded data file may be made using any of the horizontal CRSs NAD27, NAD83 or NAD83(HARN)."]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "Transformation", "name": "NGVD29 height to NAVD88 height (1)", "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 } }, "method": { "name": "Vertical Offset by Grid Interpolation (VERTCON)", "id": { "authority": "EPSG", "code": 9658 } }, "parameters": [ { "name": "Vertical offset file", "value": "vertconw.94", "id": { "authority": "EPSG", "code": 8732 } } ], "accuracy": "0.02", "scope": "Transformation of coordinates at 0.02m level of accuracy.", "area": "United States (USA) - CONUS west of 107°W - onshore - Arizona; California; Colorado; Idaho; Montana; Nevada; New Mexico; Oregon; Utah; Washington; Wyoming.", "bbox": { "south_latitude": 31.33, "west_longitude": -124.79, "north_latitude": 49.05, "east_longitude": -107 }, "id": { "authority": "EPSG", "code": 5409 }, "remarks": "Interpolation within the gridded data file may be made using any of the horizontal CRSs NAD27, NAD83 or NAD83(HARN)." }
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=vgridshift +grids=us_noaa_vertconw.tif +multiplier=1"> <Layer srs="+proj=vgridshift +grids=us_noaa_vertconw.tif +multiplier=1"> </Layer> </Map>