Integrating Landsat with MODIS Products for Vegetation Monitoring - Satellite-based Applications on Climate Change - page 241

Fig. 16.1 True color composites of a Landsat-7 ETM+ scene (WRS-2 path 15 and row 33
acquired on September 6, 2002) show that the surface reflectance ( b ) removes atmosphere effect
from TOA reflectance ( a )

a b

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Land Land

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Red NIR

Fig. 16.2 Scattering plot of surface reflectance for red ( a ) and NIR ( b ) between MODIS and
Landsat (in Fig. 16.1 ). Scale factor for reflectance is 0.0001

Figure 16.1 shows the true color composites of Landsat ETM+ reflectance
produced from the LEDAPS system for a DC scene (WRS-2 path 15 and row 33)
acquired on September 6, 2002. The TOA reflectance image looks hazier and
brighter than surface reflectance.
Comparison of surface reflectance between Landsat and MODIS shows general
good agreements. In Fig. 16.2 , surface reflectance from Landsat in Fig. 16.1 are first
aggregated to MODIS resolution (500 m) and then compared to MODIS surface
reflectance. The scattering plot shows a general 1-to-1 relationship. Some disagree-
ments may be caused by the geolocation mismatch and bandwidth differences.
A stand-alone LEDPAS software package extracted from the NASA LEDAPS
system has been released to public for scientific uses. It is freely available from the
NASA GSFC LEDAPSWeb site ( www5 ). The LEDAPS system has been adopted by