MTF
Average
% r.m.s. deviation
10 lines/mm"
0.5 ines/mm S
Ce
v
| | 1 l |
| 0 0.2375 0.475 0.7125 0.95
| Image Height
Figure 7. Image Height Characteristics of Camera C
5. CONSIDERATIONS
5.1 Measuring Range in Spatial Frequency
We started in our experiments with 50 lines/mm as the maximum
frequency for photogrammetric cameras, however, our present recommendation
of maximum frequency is 20 lines/mm from a practical point of view.
This frequency seems not high enough for on-axis (H=0), but quite
enough for off-axis as shown in Figure 5 and 6.
5.2 Choice of Fixed Frequencies for Evaluating Image Height
Characteristics
Since we found image height characteristics are very important
and also useful for photogrammetric camerd, we need to choose one or
two fixed frequencies as parameters in Figure 7 and 8. 5 lines/mm and
10 lines/mm could be recommended as the reasonable fixed frequencies.