Ontario Radar Digital Surface Model (FL) Modèle numérique de surface par interférométrie radar pour l'Ontario

Coordinate system: NAD83 / Ontario MNR Lambert (EPSG:3161)

The Ontario Radar Digital Surface Model (ORDSM) represents the average topography and generalized morphology of the reflective surface of the earth. The ORDSM was generated using data sourced from the Shuttle Radar Topography Mission (SRTM), which collected Interferometric Synthetic Aperture Radar (IfSAR). The Space Shuttle Endeavor mission performed a single pass radar interferometry from two antennae mounted 60 m apart with a swath width of 225 km. Orbiting the Earth 176 times during the 11 day mission, the SRTM successfully captured radar data for over 80% of the Earth’s land surface. A more detailed description of the SRTM mission, including publically available data, can be found here - (https://lta.cr.usgs.gov/SRTM1Arc). The horizontal extent of the Ontario Radar DSM provides continuous spatial coverage between the southern-most extent of the province (41 degrees latitude) and north to 57 degrees latitude. The horizontal coordinate system of the Ontario Radar DSM is converted from a Geographic Coordinate System to MNRF Lambert Conformal Conic projection. The horizontal datum of the Ontario Radar DSM is North American Datum of 1983 (NAD83). The elevation vertical datum of the Ontario Radar DSM is based on two different systems: • Canadian Geodetic Vertical Datum 1928 (CGVD28), which is the current national and provincial elevation data standard. GRS80 for NAD83 is used as the reference ellipsoid. • Earth Gravitational Model 1996 (EGM96), which is used by the source data. WGS84 reference ellipsoid is used. The Ontario Radar DSM has been interpolated at a consistent linear spatial resolution and geospatial coordinate system similar to other MNRF elevation products, which allows for seamless integration. Elevations are orthometric and expressed in reference to Mean Sea Level (MSL). Units of measures are in meters.