189 A High resolution mesocyclone detection algorithm with IQ data

Thursday, 29 September 2011
Grand Ballroom (William Penn Hotel)
Osamu Suzuki, Japan Meteorologcal Agency, Japan; and H. Yamauch, H. Inoue, and M. Nakazato

There are a lot of algorithms proposed by many researchers to detect small scale vortices like mesocyclone and TVS in thunderstorms. Because scales of those vortices are often comparable with azimuthal resolution most of the algorithms are suffered from beam broadening effect.

We propose a high resolution MC detection algorithm with IQ data without spectrum moment data such as Doppler velocities calculated by FFT or pulse pair processing. Modified Rankine combined vortex field is assumed as a wind field model like other similar algorithms. Uniqueness of our algorithm is that fitness of the wind filed model are evaluated with IQ data not but with Doppler velocities. To evaluate the fitness, we had to extend pulse pair method. In addition to the use of IQ data, we account for so called beam broadening effect in the evaluation of the fitness.

We conducted evolution of the performance of our algorithm with modified Rankine combined vortex fields. The results indicate some improvement on the detection algorithm.

However, there are some problems to be solved. Our algorithm is slower than past ones because of computational complexity. This problem will be overcome as CPU power increase.

- Indicates paper has been withdrawn from meeting
- Indicates an Award Winner