Calibrating SeaWinds and QuikSCAT scatterometers using natural land targets |
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| Authors: | Kunz LB Long DG |
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| Institution: | Microwave Earth Remote Sensing Lab., Brigham Young Univ., Provo, UT, USA; |
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| Abstract: | The SeaWinds-on-QuikSCAT (QuikSCAT) and SeaWinds-on-ADEOS-2 (SeaWinds) scatterometers measure the normalized radar backscatter (/spl sigma//sup o/) of the earth's surface. These identical radar sensors are on different spaceborne platforms in similar orbits. QuikSCAT and SeaWinds data are used to infer near-surface wind vectors, polar sea-ice extent, polar-ice melt events, etc. In order to verify the relative calibration of these sensors, a simple cross calibration based on land backscatter measurements is performed. A first-order polynomial model is used to remove the incidence angle dependence of /spl sigma//sup o/ for selected regions of the Amazon rainforest and the Sahara Desert. It is shown that the two sensors are well-calibrated to each other and require no bias corrections. Additionally, evidence of a diurnal cycle in the Amazon rainforest backscatter is given. |
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