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FIARKHqRD Ground Control MARKHURD Will be responsible for all necessary ground control for orthophotographic mapping. We; intend to subcontract this work to Taylor Land Surveyors, Inc., Monticello, MN. Unless specified otherwise, horizontal control will be based on Anoka County Project ',Coordinates which is based on NAD 1927 State Plane Grid System. Vertical control !will be based on Mean Sea Level datum. During the cou~'se of our survey, permanent type stations for future reference will be established. Thbse points will be properly referenced, described and shown on the maps that we furnish, !f they fall within the mapping limits. Otherwise, description information only will be furnished for your use. Aerotriangulation The aerial photography and ground control described above will be used to perform fully analytical aerotrlangulation to establish both horizontal and vertical supplemental control for orienting ind!vidual photogrammetric models. Diaposifives will be prepared, and pass point pugging Mll be accomplished on our Kern PMG-2. Measurements will be accomplished of; our Kern DSR analytical pIotters. The results will be processed using ALBANY Aeroh'iangulation program. Orthophoto Mapping We will furnish~ orthophoto maps at a scale of 1-" = 200' , showing contours at 2-fOot intervals. The ~.o~thophoto image will show all the visible physical features such as roads, railroads, fencel, buildings, drainage courses, shorelines, swamps and trees, to the extent these features are visible on the photography. The photogram ~metric models will be set up in our Kern DSR analytical stereo-plotters and a digital terr~' 'n model (DTM) will be recorded. The DTM consists of breaklines and mass points collected at a density sufficient to produce contours at 2-foot intervals. Delivery will be~in the form of reproducible positives on stable base mylar material. The contours, elevations, and geographic annotations will be plotted from the digital files and combined with the orthophoto. The orthophoto image will be screened and the line work will be shown a~ solid lines. Because of the irregular shape of the area, the ortho image will be extended to cover a full half-section sheet, but the contours will cover the green mapping limits 0nly.