Government of Canada, Natural Resources Canada, Centre for Topographic Information 2003/02/20 1.00 Raster Canadian Digital Elevation Data, Level 1 (CDED1) None Sherbrooke, Quebec, Canada Government of Canada, Natural Resources Canada, Centre for Topographic Information English, Geobase http://www.geobase.ca http://www.ctis.nrcan.gc.ca The Canadian Digital Elevation Data, Level 1 (CDED1) consists of an ordered array of ground elevations at regularly spaced intervals. The CDED1 is based on National Topographic Data Base (NTDB) digital files at scales of 1:50 000 and 1:250 000 or various scaled positional data acquired from the provinces and territories, according to the National Topographic System (NTS).The coverage for every file corresponds to half an NTS map, which means that there are western and eastern parts to the CDED1 for each NTS map. The grid spacing is based on geographic coordinates at a maximum and minimum resolution of 0.75 and 3 arc seconds for the 1:50 000, and 3 and 12 arc seconds for the 1:250 000 respectively, depending on latitude. A CDED1 file consists of elevation data recorded in metres relative to Mean Sea Level (MSL) based on the North American Datum 1983 (NAD83) horizontal reference datum. The Centre for Topographic Information (CTI) jointly produces the CDED1 with federal, provincial and territorial government agencies as well as the private sector, using terrain-modelling software.CDED1 files are delivered in ASCII format for either DOS or UNIX operating systems and are available via the File Transfer Protocol (FTP). The data should be compatible with all translators designed for the United States Geological Survey (USGS) Digital Terrain Elevation Data (DTED). The files are compressed using the PKZIP compression software. CDED1 has assumed a major role in digital mapping. The data is used in Geographic Information Systems (GIS) for land-management applications. CDED1 plays the same role as contours and relief shading on conventional paper maps but is more powerful analytically. In addition to providing estimated values of elevation points, CDED1 can be used to determine orientation and the slope of each point when used in GIS applications. CDED1 can also be used for terrain modelling, for calculating the influence of the terrain on line-of-sight, for radar imaging, for simulating flooding and similar applications. 1987/08/01 1987/08/01 Ground condition and/or production Complete Complete -136.5 -136 59.25 59 GCMD EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > CONTOURS DTM MNT EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TOPOGRAPHIC EFFECTS ELEVATION EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > DEM DEM MNE None PART OF 114P02; British Columbia,United States; Canada Data are subject to the GeoBase Unrestricted Use Licence Agreement (http://www.geobase.ca - in the Data section). Data are subject to the GeoBase Unrestricted Use Licence Agreement (http://www.geobase.ca - in the Data section). Government of Canada, Natural Resources Canada, Centre for Topographic Information Customer Support Group Mailing and physical address

2144, King Street West, Suite 010

Sherbrooke Quebec J1J 2E8 Canada +01-819-564-5600 / 1-800-661-2638 (Canada and USA) +01-819-564-5698 NTDB@NRCan.gc.ca 8h30 to 12h00 and 13h00 to 16h30 Elevation values are contained on a grid, spaced according to latitude. For the 1:50 000 scale, the spacing is always 0.75 arc second along a profile in the north-south direction and varies from 0.75 to 3 arc seconds in the east-west direction, depending upon the appropriate elevation grid spacing for the latitude zone. The spacing in metres is about 23 metres in the north-south direction and varies from approximately 8 to 17 metres between profiles (east-west direction), depending upon the latitude. The elevation grid spacing for the 1:250 000 scale is always 3 arc seconds in the north-south direction along a profile and varies from 3 to 12 arc seconds in the east-west direction, depending upon the appropriate elevation grid spacing for the latitude zone. The spacing in metres is about 93 metres in the north-south direction and varies from approximately 30 to 70 metres between profiles (east-west direction), depending upon the latitude.In some NTDB data sets, horizontal inaccuracy can vary up to 100 metres for the 1:50 000 scale and 500 metres for the 1:250 000 scale. This should not give rise to any confusion about data accuracy. The close spacing does not mean, for example, that the horizontal accuracy is equivalent to about half of the distance between two elevation points. The reason for this density is to better describe the terrain and to enhance data consistency. Data accuracy also depends on the level of detail or grid refinement that can be attained with the source material. In forming a grid, precise points must be transferred, which may alter the apparent position upon display of the point or original vector-data source. This reduces the ability to recover the positions of specific features whose dimensions are less than the internal grid cell spacing.The only measurable or perceivable errors in the CDED1 are vertical errors that may be partially attributable to horizontal errors inherent in the source data. Since conversion errors are cumulative, sometimes the data quality might be somewhat lower than that of the source data.Accuracy depends on the original source data. The current system used to classify the NTS map is based on the North Atlantic Treaty Organization (NATO) Standardization Agreement (STANAG) 2215, Edition 5.Although contours can be regenerated from the CDED1, the source data should be used for higher accuracy and to preserve as much detail as possible.Example of Data Quality Information:- Edition Source File = 1- Version Source File= 0- Altimetric Accuracy (metre) = 5- Planimetric Accuracy (metre) = 25 Waterbodies are naturally occurring areas of constant elevation (lakes) or having a small slope (rivers). Oceans and estuaries at Mean Sea Level are assigned an elevation value of zero metre. All other waterbodies are assigned their known elevations or estimated values. In the case of large bodies of water, the file is not empty but contains an estimated elevation. A body of water of unknown elevation is assigned an interpolated elevation that should be roughly equal to that of its shores. Waterbodies are represented flatter and lower than the surrounding terrain. The shore must be clearly discernible.The purpose of CDED1 production is to produce DEM data sets that accurately represent slope and elevation. Slope data is more critical to certain scientific applications than elevation data. Consequently, quality control must assure that the CDED1 is smooth within the grid and continuous from node to node, except at natural break points such as streams, cliffs, and craters.The CDED1 production process provides for drainage patterns. The methodology used to create the CDED1 is based on the USGS DTED and terrain-modelling software, which pays close attention to watercourse direction of flow. In addition, quality control is carried out to eliminate nonsense drainage activity especially along file edges. The content of the CDED1 data sets is constant since the number of elevation points per profile and the number of profiles per cell are constant for all CDED1 files (1201 x 1201). Accuracy evaluation is related to the data source(s) used to generate the product (dataset). 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114P.018) 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114P.028) 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.080) 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.088) 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.089) 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.090) 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.098) 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.099) 10 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.100) Accuracy evaluation is related to the data source(s) used to generate the product (dataset). 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114P.018) 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114P.028) 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.080) 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.088) 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.089) 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.090) 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.098) 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.099) 5 Circular Map Accuracy Standards (CMAS) (for source Terrain Resource Information Management Program, Edition 2.0, Revision 1.0-114O.100) Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic Government of British Columbia 2000/03/30 20000 Digital 1987/08/01 1987/08/01 Publication date TRIM-BC TRIM DEM mass points and breaklines are used to produce the BC CDED files. The TRIM DEM data types used are: Mass Points- definite/indefiniteBreaklines- sharp/round- hypsographic/hydrographic/anthropogenic BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 BC CDED files are derived in the following manner: - TRIM DEM mass points and breaklines were used to build a TIN. Only the most current data was used. All retired features were removed before building the TIN. All duplicate features were removed before building the TIN. - All points and breaklines were added to the TIN with zero tolerance. No features were discarded as unimportant. - All mass points were added to the TIN model with equal weight. All Breaklines were added to the model as hard breaklines. - Points were sampled from the TIN at 0.75¿ x 0.75¿ intervals using linear interpolation and written to CDED file format. Elevation value was sampled at the centre of each cell. 2012/11/30 Raster Grid cell 1201 1201 0.75 0.75 Decimal seconds NAD83 (North American Datum 1983) GRS80 (Geodetic Reference System 1980) 6378137 298.257222101 Mean sea level (MSL) / Canadian Vertical Geodetic Datum of 1928 (CVGD28) 1 Metre Explicit value (ASCII) 858 1731 Metre GeoBase Product Specifications: Canadian Digital Elevation Data, Level 1 (Edition 1.0, January 2003) Government of Canada, Natural Resources Canada, Centre for Topographic Information Customer Support Group Mailing and physical address

2144, King Street West, Suite 010

Sherbrooke Quebec J1J 2E8 Canada +01-819-564-5600 / 1-800-661-2638 (Canada and USA) +01-819-564-5698 NTDB@NRCan.gc.ca 8h30 to 12h00 and 13h00 to 16h30 Data are subject to the GeoBase Unrestricted Use Licence Agreement (http://www.geobase.ca - in the Data section). CDED ASCII (Equivalent to USGS DTED ASCII) PKZIP compression software Free 2003/02/20 Government of Canada, Natural Resources Canada, Centre for Topographic Information Customer Support Group Mailing and physical address

2144, King Street West, Suite 010

Sherbrooke Quebec J1J 2E8 Canada +01-819-564-5600 / 1-800-661-2638 (Canada and USA) +01-819-564-5698 NTDB@NRCan.gc.ca 8h30 to 12h00 and 13h00 to 16h30 FGDC Content Standard for Digital Geospatial Metadata FDGC-STD-001-1998