Dual-Polarization Phased Array Weather Radar Technology
Introduction
Dual-polarization phased array weather radar is a next-generation weather radar systems. It integrates phased array antenna with dual-polarization technology.
Phased array antenna technology
The beam is electronically steered by controlling the phase of radiating elements in the array. This significantly enhances scanning speed and flexibility.
Dual-polarization technology
The radar simultaneously transmits and receives electromagnetic waves with both horizontal (H) and vertical (V) polarization orientations.
When electromagnetic waves encounter hydrometeors (raindrops, snowflakes, hail, etc.), their scattering characteristics differ for H and V waves due to variations in particle shape, size, and phase state.
By analyzing the received dual-channel echo signals, the radar derives not only conventional parameters like reflectivity factor (z), radial velocity (v), and spectrum width (w), but also calculates several key polarimetric parameters:
- Differential Reflectivity (ZDR): Indicates particle oblateness (ratio of horizontal to vertical reflectivity)
- Specific Differential Phase (KDP): Represents the rate of change of the phase difference between H and V waves per unit path length, strongly correlated with liquid water content
- Correlation Coefficient (cc): Measures the consistency between H and V echo signals, used to distinguish precipitation types and identify non-meteorological echoes
Advantages
Dual-polarization phased array weather radar, leveraging its high temporal resolution and high data sampling rate, can detect fine features of weather systems. Through networked detection, it enables 3D wind field retrieval in overlapping coverage areas. Additionally, it demonstrates significant improvement in quantitative precipitation estimation compared to traditional weather radars, enabling a qualitative leap in meteorological monitoring. This technology significantly enhances the monitoring and warning capabilities for severe weather phenomena such as tornadoes, heavy rainfall, gust, and lightning.
