dos Santos, Joáo Roberto 
Luckman et al. (1997) comment that L band systems may be used to derive information about biomass density up to a 
limit of approximately 60 ton/ha. Furthermore one can observe that this regression function shows a high sensitivity of 
the model for values below 80 ton/ha, that corresponds to -7.73 dB (JERS-1 image) and -9.26 dB (SIR-C image), which 
is the space of attributes where different types of savanna, secondary forest or degraded forests are normally located. 
  
  
  
  
  
  
  
  
  
(a) (b) 
Biomass (ton/ha) Biomass (ton/ha) 
02 SO. 100 150 200 250 300 350 o 9 so — 100 150 200 250 300 350 
„24 
-— 
% 4. 
- 
E -6 
985 o9 e 
8 3 $c 
-1044 1 
& y 7 1.0374- Ln (x) - 12.278 -14 | y 7 2.1961 Ln (x) - 18.883 
2 R =0.6791 -161* R =0.7406 
-14 4817 
  
  
  
  
  
  
  
  
  
  
e forest $ savanna 
  
  
Figure 3. Correlation between biomass and JERS-1 (a) or SIR-C/Lyy band (b) backscatter values for forest and savanna 
formations. 
After a synoptic analysis of Fig. 3, one can perceive that SIR-C data presents a higher space on y axis, in order to 
reach the turning point of the curve, which reflects the signal saturation due to the biomass increase. 
Based on backscatter values, a slicing of both radar datasets was made. The mapping of biomass with class intervals is 
presented at Figure 4. The analysis of statistical attributes of radar images (i.e. grey level frequency) shows that the 
SIR-C products have grey level amplitudes that allow a higher performance of thematic class delineation. The result is a 
textural and homogeneous image segmentation, compared to the JERS-1 image which is less homogeneous. An 
intensive field survey with 137 georeferenced observations of different vegetation features (Krämer, 1999), support the 
significance of the biomass distribution map. 
  
  
< 5 ton/ha [ ] 30.1- 50 ion/ta 
5.1 - 10 ton/ha 
  
« 5 ton/ha 
  
30.1 - 50 ton/ha 
    
5.1 - 10 ton/ha 
  
50.1 - 70 ton/ha | 50.1 - 70 ton/ha 
  
10.1 - 15 ton/ha 
15.1 - 20 ton/ha 
[_] 20.1 - 30 ton/ha 
    
10.1 - 15 ton/ha 
70.1 - 100 ton/ha 70.1 - 100 ton/ha 
  
[| 15.1- 20 ton/ha 
> 100 ton/ha [1 20.1-20tonma [> 100 tonha 
Fig. 4 - Biomass distribution map by class intervals, for a section of test-site Comodoro (MT) in forest/savanna contact 
zones. JERS-1 (a) and SIR-C (b). 
  
  
  
  
  
380 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.