Accuracy Assessment of Canadian Digital Elevation Data using ICESat

The accuracy of the Canadian Digital Elevation Data (CDED) produced over the post was based on the accuracy of the Sources used for their creation (elevation extracted form contour lines or provincial data exchange). No means to characterize the absolute vertical precision was available, particularly in remote areas. A new production of CDED in the North is currently carried out by the Centre for Topographic Information, Natural Resources Canada with the support of the Canadian Space Agency. Approximately 1,500 new data sets are being produced. Altimetric data is partly acquired with the European Remote Sensing satellite (vis) by interferometry (70 percent) and partly by stereo-compitalion with aerial photography (30 percent). The assessment of the absolute altimetric accuracy of the CDEDs themselves as opposed from the sources is required. ICESAT lidar data gives us such on opportunity. The results obtained on the first CDED data sets produced with ERS interferometry are very promising. Accuracy for a group of 21 CDED is in the order of 0.34 m +/- 6,22 in, i.e., 10 m at 90 percent confidence level. Accuracy is recorded in the metadata of each data set. and is freely available on the GEOBASE, portal (http://www.geobase.cal),