The Production of Photo Base Map in Taiwan
5.10 Orthophoto Production
The Intergraph ImageStation is employed for contour lines plotting and orthophoto production. The orthophotographs are rectified and printed based on the digital terrain data measured from the stereo model.
5.11 Field Photo Identification
The orthophotos are field identified by the field team to add the names of places, buildings, administrative boundaries, road categories and numbers, landmarks, species of forest, crops and so forth.
5.12 Map Manuscript Compilation
The compilers are checking orthophotos and contours to ensure that are matched properly. The map corners, map borders and grids are then plotted on the orthophotos and annotations are made on the overlay of orthophotos.
5.13 Field Editing
In addition to examination at each working stages, one-tenth of the completed photomaps are selected for field editing to check if the position and elevation of ground features shown on maps meet a standard map practices, and whether the annotations and features are correct.
5.14 Drafting
The maps are drafted on different coverage's such as the contour line layer, annotation layer, image layer and so forth. The negatives of composite map film are made through the MapSetter 5000.
5.15 Photo Map Printing
The Gordon contact printer is used for the black and white photomap printing. The color map printing is carried out by the 401 mapping factory, Combine Service Force.
6 Map Distributions and Utilization
All the finished photomaps are stored and saled by the Agricultural and Forestry Aerial Survey Institute upon request. The uses of photo base maps include :
- Planning for agricultural production, forest management, resource development and land use.
- Serving as a basis for the planning of various economic projects like highways, railways, airports, harbors, telecommunication facilities, oil pipelines, industrial zone and mine field.
- Supplying the basic data for regional planning, urban development, land taxation, local construction and population censuses.
- Administration management by the government and civilian agencies.
7. Future Development
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Establishmen of the basic control points in the central mountain areas.
- Study on the production of 1/5,000 map by using the IKONOS satellite images with 1 m resolution
- Introduce the Synthetic Aperture Radar (SAR) to overcome the weather problem.
8. Conclusion
In order to meet the tendency of digital mapping system, the Institute purchased the advanced aerial survey airplane with GPS navigation and RMK TOP aerial cameras, digital mapping instruments year by year. From the trial to mass production, it is really a journey to undergo all the hardships.
At present, 15,160 sheets of analog photomaps and 1,580 sheets of digital photomaps have been completed. These completed photo base maps are widely used by the people of all sectors and have won nation-wide acclamation because of their delicacy and accuracy. It has made an outstanding contributions to the promotion of photomap production and national economic development in Taiwan.
References :
- Intergraph, July 1993.ImageStation Stereo Display (ISSD) User's Guide.
- ZEISS, August 1996.AutoScan (TD) User's Guide
- Ministry of Interior, Executive Yuan., September 1996. Mapping Standard for Digital Photo Base Map.
