Adaptive ESA Weather Radar Antenna Tapering
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Solution Overview
Problem
Commercial aircraft are vulnerable to microburst and windshear threats during landing, particularly due to strong ground clutter interference in traditional airborne weather radar systems, which can lead to false warnings and increased fuel consumption.
Innovation Solution
A system and method using an electronically scanned array (ESA) weather radar that adaptively adjusts the amplitude and phase of its elements to create a null associated with ground clutter returns, maintaining signal-to-noise ratio sensitivity to receive weather returns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the weather radar antenna beam is tilted downward to illuminate hazardous weather near the ground, then the detection capability for low-altitude weather threats is improved, but strong ground clutter is displayed which precludes display of actual weather threats
Solution Approach 1:
The patent applies local quality by creating a null (region of minimal sensitivity) in a specific directional location corresponding to ground clutter sources, while maintaining normal sensitivity in other directions for weather detection. This is achieved through adaptive adjustment of amplitude and phase of individual ESA elements to produce direction-dependent response characteristics.
Solution Approach 2:
The patent converts the harmful ground clutter interference into a beneficial effect by using the clutter return itself as feedback to adaptively shape the radiation pattern. The ground clutter signal, initially harmful, becomes the basis for creating a null that suppresses future clutter returns, transforming the problem into a solution mechanism.
2Measurement precision
If electronic scanned array is used with higher sidelobe content to enhance weather detection, then the sensitivity for detecting hazardous weather is improved, but ground clutter echoes are exacerbated
Solution Approach 1:
The patent changes the radiation pattern parameters (amplitude and phase distribution across ESA elements) adaptively based on detected ground clutter characteristics. By dynamically adjusting these parameters, the system optimizes the balance between maintaining weather detection sensitivity and suppressing ground clutter echoes in real-time.
Solution Approach 2:
The patent implements feedback by using the received ground clutter returns to continuously adjust the ESA element parameters. The system monitors clutter levels and adapts the radiation pattern accordingly, creating a closed-loop control mechanism that maintains optimal performance despite varying clutter conditions.
3Object-generated harmful factors
If traditional ground clutter suppression methods are applied, then ground clutter display is reduced, but computationally extensive processing is required which may be cost prohibitive
Solution Approach 1:
The patent replaces complex computational ground clutter suppression mechanisms with a simpler antenna-based solution. Instead of using heavy computational assets for post-processing clutter removal, the system uses adaptive antenna parameter adjustment to suppress clutter at the signal reception stage, reducing the need for extensive onboard computational processing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively minimizes ground clutter interference, allowing the weather radar to accurately display hazardous microburst weather phenomena, thereby enhancing aircraft safety and reducing operational costs.
Implementation Method 1
the adaptive adjustment creates a null associated with the ground clutter return, the adaptive adjustment maintains a signal to noise ratio (SNR) sensitivity of the weather radar to receive a weather return
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
A system and method for applying an adaptive adjustment or taper to an electronically scanned array (ESA) weather radar based on feedback from the weather radar (110). To minimize ground clutter and enable the ESA (112) to display hazardous weather phenomena, the system adaptively adjusts amplitude and phase of ESA elements to adjust the far field pattern shape and sidelobes to maintain a desirable signal to clutter ratio. The system identifies ground clutter as a strong ground return over several azimuths depending on the radar beamwidth. Once the system IDs the ground clutter, it adaptively adjusts on receive for for the upcoming azimuths. The system selectively suppresses sidelobe echoes while maintaining the signal to noise (SNR) for weather targets. The system adaptively adjusts in real time as well as adjusting using precomputed historically accurate tapers stored in memory (122).