In: Wagner W., Székely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
DSM calculated by Infoterra’s 
Pixel Factory™ 
DSM calculated using the 
procedure explained above 
Figure 3. Comparison of the DSMs 
The absolute mean error is not very high, but our DSM is quite 
noisy. The standard deviation of the error is quite high. The 
GPS control point with the largest absolute error of -68 m is lo 
cated near the northwestern mountain peak. In Figure 4 and 
Figure 5 the details of the DSMs marked by white boxes in Fig 
ure 3 can be seen. 
Subset of the Pixel Factory™ 
DSM on the mountain ridge 
Subset of our DSM on the 
mountain ridge 
Figure 4. Detailed DSM comparison 
Subset of the Pixel Factory™ 
DSM on the mountain ridge 
Subset of our DSM on the 
mountain ridge 
Figure 5. Detailed DSM comparison 
The DSM created by Infoterra’s Pixel Factory™ includes large 
areas with no value in Figure 4, whereas our DSM interpolates 
all areas. Pixel Factory™ is marking the areas where no or no 
reliable information is available. This is an important feature of 
the Pixel Factory™ for mapping applications. 
Our DSM is overestimating the heights at the mountain ridges 
compared to the results from Pixel Factory™. The resulting 
DSM is noisier, which can be seen very clearly in Figure 5. The 
mountains are quite comparable to each other, but in the rather 
flat area on the eastern side of the subset shown in Figure 5 our 
radargrammetric processor produces very noisy results. This is 
still the main problem of our approach. 
Figure 6 shows the correlation value of the whole scene. The 
river is very striking with a high correlation value. The lower 
and flat area near the river also has a high overall correlation, 
but the results in this area are still noisy. Along the hillside of 
the mountainous areas the overall correlation is much lower. 
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