航空用の地図についての考察
No map can perfectly reproduce the earth. The globe comes nearest to accomplishing this. Yet maps are valued more than the globe today because of their vastly superior utility. That the Mercator projection more than all others has been continuously used through the years may be explained by the fact...
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Format: | Report |
Language: | Japanese |
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横浜国立大学
1953
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Online Access: | http://hdl.handle.net/10131/2043 https://ynu.repo.nii.ac.jp/?action=repository_uri&item_id=913 https://ynu.repo.nii.ac.jp/?action=repository_action_common_download&item_id=913&item_no=1&attribute_id=20&file_no=1 |
Summary: | No map can perfectly reproduce the earth. The globe comes nearest to accomplishing this. Yet maps are valued more than the globe today because of their vastly superior utility. That the Mercator projection more than all others has been continuously used through the years may be explained by the fact that navigators believed loxodromics was the best means of navigation. It seems to me, the Mercator projection should be replaced by any one of several others based upon orthodromics, since they are more useful in this Air Age. Perhaps both inertia from the past and ignorance of other map projections caused the delay in replacement of the older map projections. In the new Air Age in which all of us live the most useful maps are those which fulfill the following three conditions: 1) maps which give great circles as straight lines; 2) maps which give true azimuths; 3) maps which locate the North Pole somewhere in them. Even though a single projection cannot meet these three requirements, I believe the oblique equidistant azimuthal projection, the oblique simple cylindrical projection and the oblique equal-area cylindrical projection are to be recommended as best suited for the purpose. In the comparison of the simple cylindrical projection with the equidistant azimuthal projection, the former is found to have a determinative advantage in that it necessitates neither a scale nor a protractor as the result of starightening up the parallels, while, in the latter, its user requires both. The equal-area cylindrical projection has even more merit than the simple cylindrical projection. In the former, the areal relationships on the earth are kept true. The distances from the centre of the projection can be easily read on the Y-axis although the distance relationships on the earth are no longer preserved. In terms of the conventional concept of maps, the shape distortions at the margins of each of these three projections are so conspicuous that they would hardly be put in the category of maps. This is particularly true of the ... |
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