Hiroshima Institute of Technology (HIT) is operating the direct down-links of microwave and optical earth observation
satellite data in Japan. This study focuses on the validation for rice crop monitoring using microwave remotely sensed
image data acquired by ENIVISAT-1 referring to ground truth data such as height of rice crop, vegetation cover rate and
leaf area index in the test sites of Hiroshima district, the western part of Japan.
ENVISAT-1/ASAR data has the capabilities for the monitoring of the rice crop growing cycle by using alternating cross
polarization mode images. However, ASAR data is influenced by several parameters such as land cover structure,
direction and alignment of rice crop fields in the test sites. In this study, the validation was carried out to be combined
with microwave image data and ground truth data regarding rice crop fields to investigate the above parameters. Multi-temporal,
multi-direction (descending and ascending) and multi-angle ASAR alternating cross polarization mode images
were used to investigate during the rice crop growing cycle. On the other hand, LANDSAT-7/ETM+ data were used to
detect land cover structure, direction and alignment of rice crop fields corresponding to the backscatter of ASAR.
Finally, the extraction of rice planted area was attempted by using multi-temporal ASAR AP mode data such as VV/VH
and HH/HV. As the result of this study, it is clear that the estimated rice planted area coincides with the existing
statistical data for area of the rice crop field. In addition, HH/HV is more effective than VV/VH in the rice planted area