The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008 
2.2 Materials 
Old aerial photographs, which we used in this study, were 
acquired during 1946 to 1956 by US forces. These are 
panchromatic photos at 1/10,000 - 1/40,000 scales. PRISM 
products (DSM, Ortho images) acquired on XX Jan 2007 were 
utilized to get references for ortho rectification of old aerial 
photographs. As a reference for a validation of positional 
accuracy, 1 /25,000 scale topographic maps provided by 
Geographical Survey Institute (GSI) were used. GSI has a huge 
amount of archives, since each'map are updated to the latest 
versions every 10 years at least. Topographic maps were 
published around 1946. To get land use information and land 
condition information of the prefecture, we also used Digital 
Map 5000 (Land Use) and 1/25,000 Scale Land Condition 
Maps, which are also provided by GSI. 
Figure 1. Test site (PRISM ortho image) 
3. TREND ANALYSIS OF LAND USE / FORM CHANGE 
We sampled some areas to confirm trend of typical land 
changes in each sites using PRISM products and old aerial 
photos. Futhermore, we applied thresholds for validating the 
landform/land use for each area. The analysis helped to simply 
grasp the overall effects caused by many complex factors. In 
addition, those changes were detected by visual check. 
3.1 Sampled Area 
Area 1: Plural small communities connected. 
Figure 2. Old aerial photo (1/20,000 15 Aug 1946) 
Figure 2. PRISM Ortho Image (31 Jan 2007) 
Area 2: The framework is same as before. 
Figure 4. PRISM Ortho Image (31 Jan 2007) 
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