Shuttle Imaging Radar: SIR-C
April 16, 1994
CHH,LHH,LHV: RGB
Lago Cabaliana
Landsat Thematic Mapper
August 2, 1989
NPV, GV, Soil: RGB
5km
FIGURE 1.4. Comparison of SIR-C data and LANDSAT TM data for Lago Cabaliana, approximately 60 km southwest of the city of Manaus in central Amazonia. SIR-C CHH, LHH and LHV data from April, 1994, are displayed
on the left as red, green, and blue, respectively. Flooded forests are evident as regions that are yellowish white due
to a strong LHH double-bounce return, high C and low LHY. Recent cIearcuts in the northeastern portion of the image
have low returns in all three channels due to low standing biomass. The image to the right shows a LANDSAT TM
scene acquired in same area on August 2, 1989. This image has been analyzed using spectral mixture analysis, generating fraction images for nonphotosynthetic vegetation, green vegetation, and soil, displayed as red, green, and blue
(Roberts et aI. , 1993). Unlike the SAR image, the optical data are relatively insensitive to the presence of standing
water and do not differentiate macrophytes from flooded forests. Spectral fractions vary primarily in response to the
materials within the field of view and subpixel shadowing due to variation in leaf angles, crown shading, and the presence of canopy gaps. In this image, second-growth forest is readily separated from primary forest by a low shade content, which produces light green vegetation along the margins of rivers. Flooded forest, which commonly has a more
uniform crown height than upland forest, is more homogeneous and is differentiated in many places by a lower shade
content. Recent cIearcuts are modeled primarily as nonphotosynthetic vegetation due to the presence of fallen logs
and senesced grasses.
April 16, 1994
CHH,LHH,LHV: RGB
Lago Cabaliana
Landsat Thematic Mapper
August 2, 1989
NPV, GV, Soil: RGB
5km
FIGURE 1.4. Comparison of SIR-C data and LANDSAT TM data for Lago Cabaliana, approximately 60 km southwest of the city of Manaus in central Amazonia. SIR-C CHH, LHH and LHV data from April, 1994, are displayed
on the left as red, green, and blue, respectively. Flooded forests are evident as regions that are yellowish white due
to a strong LHH double-bounce return, high C and low LHY. Recent cIearcuts in the northeastern portion of the image
have low returns in all three channels due to low standing biomass. The image to the right shows a LANDSAT TM
scene acquired in same area on August 2, 1989. This image has been analyzed using spectral mixture analysis, generating fraction images for nonphotosynthetic vegetation, green vegetation, and soil, displayed as red, green, and blue
(Roberts et aI. , 1993). Unlike the SAR image, the optical data are relatively insensitive to the presence of standing
water and do not differentiate macrophytes from flooded forests. Spectral fractions vary primarily in response to the
materials within the field of view and subpixel shadowing due to variation in leaf angles, crown shading, and the presence of canopy gaps. In this image, second-growth forest is readily separated from primary forest by a low shade content, which produces light green vegetation along the margins of rivers. Flooded forest, which commonly has a more
uniform crown height than upland forest, is more homogeneous and is differentiated in many places by a lower shade
content. Recent cIearcuts are modeled primarily as nonphotosynthetic vegetation due to the presence of fallen logs
and senesced grasses.