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PALSAR is an active microwave sensor, which is not affected by weather conditions and operable both daytime and nighttime. It is improved based on Synthetic Aperture Radar (SAR) onboard the first earth observation satellite (JERS-1).
Full polarimetry (multi-polarization), off nadir pointing function and other functions of PALSAR improved the accuracy of analyzing geological structure, distribution of rocks and so on, and expected to contribute resource exploration and other purposes more effectively.
At the same time, multi-polarization is effective in acquiring vegetation information, which encourages the data use in fields such as global and regional observation of vegetation, distinguishing features on the ground, classification of land use and other purposes.
In addition, PALSAR is suitable to flexibly correspond to emergencies such as wide-ranging natural disasters.
| Main Characteristics of PALSAR |
| Mode |
Fine |
ScanSAR |
Polarimetric |
| Center Frequency |
1270MHz(L-band) |
| Bandwidth |
28MHz |
14MHz |
14,28MHz |
14MHz |
| Polarization |
HH or VV |
HH+HV or VV+VH |
HH or VV |
HH+HV+VH+VV |
| Incidence angle |
8 ~ 60deg. |
8 ~ 60deg. |
18 ~ 43deg. |
8 ~ 30deg. |
| Range Resolution |
7 ~ 44m |
14 ~ 88m |
100m |
24 ~ 89m |
| Swath |
40 ~ 70km |
40 ~ 70km |
250 ~ 350km |
20 ~ 65km |
| Quantization |
5bits |
5bits |
5bits |
3 or 5bits |
| Data rate |
240Mbps |
240Mbps |
120Mbps, 240Mbps |
240Mbps |
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PALSAR has the following 3 observation modes.
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Fine mode |
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This observation mode is the most commonly used under regular operation. Its maximum ground resolution of 7m is one of the highest as a Synthetic Aperture Radar (SAR) (for comparison, SAR onboard JERS-1 was about 18m resolution) loaded on a satellite.
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ScanSAR mode |
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ScanSAR mode enables to switch off-nadir angle from 3 to 5 times (scan by the swath of 70km) to cover wide area from 250km (70x3) to 350km (70x5) (for comparison, swath width of SAR onboard JERS-1 was about 75km). However, the resolution is inferior to high-resolution mode.
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Polarimetric mode |
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SAR on JERS-1 was equipped with horizontal polarization transmission/receipt function only, whereas PALSAR realized both horizontal and vertical polarization. PALSAR can also simultaneously receive horizontal and vertical polarization per each polarized transmission, which is called multi polarimetry. In addition, PALSAR can switch from horizontal to vertical polarization and vice versa at respective transmission pulse, enabling four polarizations by double simultaneous polarization, a function called full polarimetry.
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