Airborne polarimetric Doppler weather radar: trade-offs between various engineering specifications
NCAR EOL is investigating potential configurations for the next-generation airborne phased array radar (APAR) that is capable of retrieving dynamic and microphysical characteristics of clouds and precipitation. The APAR will operate at C band. The APAR will use the electronic scanning (e-scan) f...
Main Authors: | , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2018-01-01
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Series: | Geoscientific Instrumentation, Methods and Data Systems |
Online Access: | https://www.geosci-instrum-method-data-syst.net/7/21/2018/gi-7-21-2018.pdf |
Summary: | NCAR EOL is
investigating potential configurations for the next-generation airborne
phased array radar (APAR) that is capable of retrieving dynamic and
microphysical characteristics of clouds and precipitation. The APAR will
operate at C band. The APAR will use the electronic scanning (e-scan) feature
to acquire the optimal number of independent samples for recording research-quality measurements. Since the airborne radar has only a limited time for
collecting measurements over a specified region (moving aircraft platform
∼ 100 m s<sup>−1</sup>), beam
multiplexing will significantly enhance its ability to collect
high-resolution, research-quality measurements. Beam multiplexing reduces
errors in radar measurements while providing rapid updates of scan volumes.
Beamwidth depends on the size of the antenna aperture. Beamwidth and
directivity of elliptical, circular, and rectangular antenna apertures are
compared and radar sensitivity is evaluated for various polarimetric
configurations and transmit–receive (T/R) elements. In the case of polarimetric
measurements, alternate transmit with alternate receive (single-channel
receiver) and simultaneous reception (dual-channel receiver) is compared.
From an overall architecture perspective, element-level digitization of
T/R module versus digital sub-array is considered with
regard to flexibility in adaptive beamforming, polarimetric performance,
calibration, and data quality. Methodologies for calibration of the radar and
removing bias in polarimetric measurements are outlined. The above-mentioned
engineering options are evaluated for realizing an optimal APAR system
suitable for measuring the high temporal and spatial resolutions of Doppler
and polarimetric measurements of precipitation and clouds. |
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ISSN: | 2193-0856 2193-0864 |