{"$schema":"https://proj.org/schemas/v0.7/projjson.schema.json","type":"VerticalCRS","name":"DNN height","datum":{"type":"VerticalReferenceFrame","name":"Dansk Normal Nul"},"coordinate_system":{"subtype":"vertical","axis":[{"name":"Gravity-related height","abbreviation":"H","direction":"up","unit":"metre"}]},"scope":"Engineering survey, topographic mapping.","area":"Denmark - onshore.","bbox":{"south_latitude":54.5,"west_longitude":7.98,"north_latitude":57.81,"east_longitude":15.28},"id":{"authority":"EPSG","code":5733}}