Process step:
TIFFs of the original maps were heads-up digitized on screen using a georeferenced image in ArcInfo(R). Where terrain polygon boundaries stop and start at water bodies, the digitizer used best judgement to close the polygon. Water polygons disappear as terrain boundaries are extended into the water and closed in the middle of the water body: the lines of closure are as far away from the shore as possible. Very large water bodies are coded as LAKE. Standard 1:100 000 NTS neatlines were produced based on geographic coordinates of the 4 corners of each map. The images were georeferenced again upon completion of final terrain polygon edits to UTM NAD83 using the georeferencing tool in ArcMap 8.1. The Natural Resource Values Information System (NRVIS) water data was used for georeferencing. The georeferenced image was stored in TIF format in UTM NAD83 projection. All line work was captured in double coordinate precision.
Process step:
Field surveys were undertaken to verify the terrain conditions obtained from the air photo interpretation; these were carried out by the senior interpreters. Because of the reconnaissance nature of the study and the inherent time constraints, the field checking took the form of a 'windshield survey'. Prominent natural and man-made cuts were examined, and, in some cases, soil materials were sampled. Geological observations were recorded on a continuous basis along most of the accessible roads and highways within the map areas. A helicopter reconnaissance survey was conducted in the inaccessible area north of Lake Nipigon. A few shallow hand auger holes were drilled by some of the investigators, and a number of photographs were taken. The information from the field survey and literature research was combined with the airphoto interpretation results to produce the Data Base Map and written report for each map area.
Ontario Ministry of Northern Development and Mines - Ontario Geological Survey: Northern Ontario Engineering Geology Terrain Studies (NOEGTS): Heads up digitization of georeferenced raster TIFF scanned files of the Northern Ontario Engineering Geology Terrain Study hard copy paper cartographic maps. Interpretation of air photos, map compilation and limited ground truthing done between 1977 and 1979 Data collected from 01/01/1977 to 31/12/1979. The original cartographic maps were created through the review of relevant literature to provide a source of published information, air photo interpretation to identify and classify the terrain types, and field surveys to verify ground conditions at specific locations.
Ontario Ministry of Northern Development and Mines - Ontario Geological Survey: MNDM Surficial Geologist: An MNDM Surficial Geologist used NTS cartographic maps and his expertise to make corrections to the digitized polygon layer. Specifically to divide polygons with multiple labels and to create labels for those polygons that lacked them. Data collected from 01/01/2001 to 31/03/2004. Notes on the rationale for the changes to polygons exist for every map which was edited.
Ontario Ministry of Natural Resources: Ontario Ministry of Natural Resources Air Photos: The principal technique for obtaining terrain information was stereoscopic air photo interpretation. The terrain units were delineated on contact prints of these air photos and decisions were made regarding the terrain type and its distribution. Between977 and980, this interpretation was carried out on approximately2 000 vertical air photos which varied in scale from:38 000 to:70 000. The interpretations were transferred manually from the contact prints onto photo mosaics at a scale of:100 000. From these mosaics, the information was traced to the finished base map at the same scale. 12,000 vertical air photos.
Ontario Ministry of Natural Resources: Land Information Ontario, Natural Resource Values Information System Base Map (NRVIS): base map information including water bodies and roads. Field surveys were undertaken to verify the terrain conditions obtained from the air photo interpretation; these were carried out by the senior interpreters. Because of the reconnaissance nature of the study and the inherent time constraints, the field checking took the form of a 'windshield survey'. Prominent natural and man-made cuts were examined, and, in some cases, soil materials were sampled. Geological observations were recorded on a continuous basis along most of the accessible roads and highways within the map areas. A helicopter reconnaissance survey was conducted in the inaccessible area north of Lake Nipigon. A few shallow hand auger holes were drilled by some of the investigators, and a number of photographs were taken. The information from the field survey and literature research was combined with the airphoto interpretation results to produce the Data Base Map and written report for each map area.
National Aeronautics and Space Administration (NASA): Shuttle Radar Topography Mission Digital Elevation Model (SRTM): shaded relief raster image, aquired from the USGS web site in tiles and merged using ESRI GRID.
Ontario Ministry of Natural Resources: Land Information Ontario, Natural Resource Values Information System Base Map (NRVIS): base map information. Water bodies and major roads.