Monday, 28 August 2023: 2:45 PM
Great Lakes BC (Hyatt Regency Minneapolis)
The XPC is a novel technique for reducing the cross-polar contamination in polarimetric phased array weather radars. Cross-polar contamination refers to contamination in the intended polarization that a radar is transmitting caused by a leak in the perpendicular polarization. This is problematic because it can impact polarimetric radar data quality (causing biases in the polarimetric variables used to characterize and measure weather).
The XPC technique repurposes a small group of elements in the array as canceller elements. These canceller elements transmit the negative of the original waveform in the perpendicular polarization, where the cross-polar contamination is generated. It is expected that, after integration, the energy transmitted by the canceller elements can at least partially cancel the cross-polar contamination. However, to achieve optimal results, the number of canceller elements must be carefully tuned and distributed in the array, with each element independently modulated in amplitude and phase for each polarization (using scaling factors).
The XPC technique optimizes the number and location of the canceller elements in the array and calculates the corresponding scaling factors to modulate each element per steering angle. This allows for the best cross-polar isolation to be achieved throughout the scanning region when the array is electronically steered.
In previous research efforts the authors evaluated the performance of the XPC technique through simulations. This work complements and expands upon those studies by evaluating the performance of XPC using experimental results from actual antenna pattern measurements. To this end, 2-D element pattern measurements from an 8×8 array will be used, and digital beamforming will be applied. The beams computed through conventional beamforming will be compared to those from XPC, and the cross-polar isolation will be quantified with and without XPC. The authors anticipate good agreement between the simulated and experimental results.
The XPC technique repurposes a small group of elements in the array as canceller elements. These canceller elements transmit the negative of the original waveform in the perpendicular polarization, where the cross-polar contamination is generated. It is expected that, after integration, the energy transmitted by the canceller elements can at least partially cancel the cross-polar contamination. However, to achieve optimal results, the number of canceller elements must be carefully tuned and distributed in the array, with each element independently modulated in amplitude and phase for each polarization (using scaling factors).
The XPC technique optimizes the number and location of the canceller elements in the array and calculates the corresponding scaling factors to modulate each element per steering angle. This allows for the best cross-polar isolation to be achieved throughout the scanning region when the array is electronically steered.
In previous research efforts the authors evaluated the performance of the XPC technique through simulations. This work complements and expands upon those studies by evaluating the performance of XPC using experimental results from actual antenna pattern measurements. To this end, 2-D element pattern measurements from an 8×8 array will be used, and digital beamforming will be applied. The beams computed through conventional beamforming will be compared to those from XPC, and the cross-polar isolation will be quantified with and without XPC. The authors anticipate good agreement between the simulated and experimental results.
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