Acquired aerial photography (1:5000 to 1:60 000 scale).
Performed aerotriangulation of photography, geo-referencing all photogrammetric controls to true ground coordinates.
Collected vector digital data using analogue plotters (Wild A10 - A8 - B8S). Vector data were three dimensional (x,y,z) and geo-referenced to UTM coordinates. The output format was DXF.
Performed cursory checks of digital data (removal of pseudo nodes, creation of polygons, etc.).
Built lines and points then copied attribute information from the ACODE and XCODE tables into the arc and point attribute tables (AAT and PAT). Dropped five attribute fields from the resulting attribute tables.
Selected arcs representing hypsography lines based on the dxf-layer attribute. Put the arcs for each category to respective ArcInfo coverages then appended all hypsography line layers into one coverage and built as line.
Appended mapsheet hypsography line coverages into a Manitoba-wide coverage. Unsplit arcs based on dxf-elevation and dxf-layer. Performed edits to ensure good edgematching. Assigned dxf-elevation to arcs with zero values by checking the elevation of surrounding contours.
To ensure that the elevation value did not vary over the length of a contour, created a coverage for each dxf-elevation value and checked for and corrected dangles. If dangles were a result of an open-ended contour, added an arc to close the contour.
Re-appended all elevation coverages and ran the intersecterr command to detect arc intersections within the coverage. At intersections, manually made vertex movements, averaging 0.5 meters, to correct for overlaps.