1. Radar Application in Weather Forecast EECS 725 Chao Jiang 05/01/2015

2. Radar Application in Weather Forecast Introduce to Weather Radar Typical Weather Radar Specification Limitation and Future Development

3. Weather Radar Most of the weather radars are monostatic radars. Capable of detecting location of precipitation, calculating the motion of rain droplets, and its intensity. Usually operates in S-band and C-band. X-band weather radar is used only to detect nearby target, and Ka-band is used to research small-particle phenomenon. Ground, Airborne, and Spaceborne.

4. Introduce to WSR-88D Weather Radar WSR-88D Network (160 Radars), operated by National Weather Service Deployed across the US in the 1990s. Was the first radar able to detect particle motions. Operates in S-band (Frequency: 3.1 GHz; wavelength: 10.5 cm)

5. Basic Structure

6. Dual-polarization

7. Differentiating Rain and Snow. Detecting Hail Cores. Debris from Significant Tornadoes.

8. Limitations (Beam Height) Due to the curvature of the Earth.

9. Limitations (Beam Height)

10. Limitations (Attenuation) Occurs when large objects scatter most of the microwave. Makes the storms behind the large object appear weaker

11. Limitations (PRF constraints) PRF min = 2 Δf D PRF max = c/2R max Multiple scans at each angle Change PRF at the radar depending on the situation

12. Future development (Phased Array) Consists of four stationary panels. Providing rapid scanning. Able to scan the sky in less than 1 minutes (more than 4 times faster than WSR-88D). Making the observation more accurate and reduce false alarms.

13. Phased Array Radar in Norman, Oklahoma

14. Reference http://www.meteor.iastate.edu http://www.wdtb.noaa.gov http://www.nssl.noaa.gov