Synergistic Use of Satellite Active and Passive Microwave Observations to Estimate Typhoon Intensity

Typhoon (TC) is one of the most powerful and destructive natural disasters. The analysis and determination of TC intensity is of great importance for disaster prevention [1] - [3] . Satellite remote sensing has become an effective means of monitoring TCs based on its high temporal and spatial resolution and large coverage. It is possible to estimate TC intensity using these satellite measurements when direct measurements are not available [4] . Microwave observations from polar-orbiting satellites can play a crucial role in revealing convective organization and eyewall structure that would otherwise be obscured by cloud tops [5] . Passive microwave sensors, such as SSM/I, TRMM/TMI, have been used to estimate TC intensity [6] - [10] . Besides, scatterometer also has allowed for continuous observation of ocean surface vector winds. Thus, scatterometer is a potential alternative for monitoring TCs. However, scatterometer measured wind speed range 2-24m/s, which make it very difficult to directly obtain the intensity of TCs [11] .