I have to do some programming work with DEM files.
I got some DEM files from http://geobase.ca/geobase/en/find.do?produit=cded the 1:50,000 version and read in the data. According to the DEM specifications, there is a quote:
"... a 4x2 array containing the ground coordinates of the quadrangle boundary for the DEM. The coordinates of the quadrangle corners are ordered cloclwise direction beginning with the SW corner. The array is stored as pairs of eastings and northings."
Question: 1. Is easting and northing same as UTM metric? 2. Are UTM coordinates supposed to be written as easting-northings or northing-eastings? 3. What is the standard unit for UTM coord? meters? arc seconds? In the DEM file I have, I figured it is in arc seconds. 4. How to I convert, specifically for this DEM (see above) I have, from the "4x2" array to meters?
Below is one of the DEM header data I extracted. Which this data, specifically, the SE coord (2nd line) and the 4x2 array (SW, NW, NE, SE coord) is it sufficient to point on the map where this quadrangle is? I tried very hard to map this data to Google Earth but I cannot seem to work out the maths... hope someone can enlighten me.
DEM Name: 092g01DEMe SE Coord: -12215 0.0000, 49 0 0.0000 DEM Level Code: 1 Ground Reference System: Geographic Ground Reference Zone: 0 Ground Unit: arc_seconds Elevation Unit: meters Ground Resolution (lat, lng, elev): 0.75, 0.75, 1 Elavation Array Szie: 1201 x 1201 Percentage void: 0 SW Coord: -440100, 176400 NW Coord: -440100, 177300 NE Coord: -439200, 177300 SE Coord: -439200, 176400