The consumer digital stereo camera FinePix REAL 3D W1, which was designed to take a pair of stereo images for stereo
viewing, was released in August 2009. The aim of our study is to evaluate camera calibration methods for a low-cost and
easy-operation system to measure dimensions of an object on a sub-meter scale only by using a pair of stereo images
acquired by the camera without any controls such as control points whose spatial locations are known or a ruler which
provides the scale of the object. Three camera calibration methods were evaluated by estimation errors of lengths of line
segments measured without any controls. The experiment results indicate that the best calibration method would be the
method that ordinary camera calibration is first executed for each imaging unit in order to estimate its image distortion
model, and then alignment between two imaging units is estimated by using two sets of the exterior orientation
parameters of both imaging units obtained in the ordinary camera calibration executed previously. The experiment
results indicate that the suitable calibration method would be able to provide sufficiently accurate measurement results
less than 0.4 pixels on an image as well.
The Hiroshima Institute of Technology (HIT) manages direct downlinks for microwave and optical earth observation satellite data in Japan. This study focuses on validating rice monitoring using ground truth data from ENIVISAT-1/ASAR, such as the height of rice crop, vegetation cover, and leaf area index in test sites in the Hiroshima district in Japan. ENVISAT-1/ASAR data can monitor the rice-crop growing cycle using alternating polarization (AP) mode images. However, ASAR data is influenced by several parameters, such as land-cover structure, and the direction and alignment of rice fields in the test sites. To investigate these parameters, in this study the validation was combined with microwave image data and ground truth data for rice-crop fields. Multitemporal, multidirection (descending and ascending), and multiangle ASAR AP-mode images were used to investigate the rice-crop growing cycle. Finally, the extraction of rice-planted areas was attempted using multitemporal ASAR AP mode data, such as VV/VH and HH/HV. This study clarifies that the estimated rice-planted area agrees with the existing statistical data for areas within the rice field. In addition, HH/HV is more effective than VV/VH in extracting the rice-planted area.
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
extraction.
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