00000nam 2200000zi 4500 9.892199 CaOODSP 20221107173113 m o d f cr |n||||||||| 201006s1992 oncb ob f|0| 0 eng d CaOODSP eng rda CaOODSP eng fre n-cn--- Co24-3/7-92-002E-PDF Whitteker, J. H. (James Howard), 1940- author. Storage specifications for 500-metre-grid terrain data / by J.H. Whitteker. Ottawa : Government of Canada, Department of Communications = Gouvernement du Canada, Ministère des Communications, 1992. 1 online resource (24 pages) : maps. text txt rdacontent computer c rdamedia online resource cr rdacarrier CRC report ; CRC-RP-92-002 Digitized edition from print [produced by Innovation, Science and Economic Development Canada]. "August 1992." Includes bibliographical references (page 14). "Terrain data for much of Canada and some adjoining U.S. territory are stored compactly in a binary format. The format was designed to be used for obtaining elevations and surface type information along radio propagation paths, but it may be used whenever compact, rapidly-accessible terrain data are required. Terrain points are the intersections of a 500-metre grid defined on the UTM (Universal Transverse Mercator) co-ordinate system. A teach point, an elevation is stored, and a code indicating surface type (bare ground, tree covered, lake, sea, buildings) is also stored wherever it is available. The information for each point occupies 16 bits. A record occupies 1024 bytes, and corresponds to a 7.5 x 15.5-km rectangle. With this arrangement, points that are geographically close together are usually also close together in the data file. A file represents an area 40 of latitude by 6° of longitude. Each file contains its own index in the first six records"--Abstract. Includes abstract in French. Topographic maps Data processing. Cartes topographiques Informatique. Canada. Department of Communications, issuing body. CRC report ; CRC-RP-92-002. (CaOODSP)9.882492 PDF 3.03 MB https://publications.gc.ca/collections/collection_2020/isde-ised/Co24/Co24-3-7-92-002-eng.pdf