4. Result
The observation date was a sunny day but windy day, then the plane rolled and pitched very much. It was very hard to get high -resolution data, and we used kinematic GPS data. Though there are some obscure area because of the strong wind, we can get detailed information, such as 1.5m resolution, in most area of the image. The features in the DEM by Airborne SAR, such as, valleys and hills almost correspond with the positions of these features shown in the topographical map.
Figure 1 the basic map around observed area
(1:50,000 topographical map "Ito", published by GSI Japan)
The result of comparison between the DEM by Airborne SAR and by aerial photos is shown in Figure 4. The difference between two DEMs is around 8m for whole area and as good as 5m in some area. This result shows that we can get an accurate DEM whose residual is around a half of interval between two contours that are shown in 1:50,000 basic topographical maps.

Figure 2. Visualized SAR Image



Figure 3 DEM image (gradations)



Figure 4 Comparing two DEMs, by Airborne SAR and aerial photographs
(Thick line : DEM by SAR Thin line : DEM by photo)