A Novel Instrument for Real-Time Measurement of Attenuation of Weather Radar Radome Including Its Outer Surface. Part I: The Concept

Mancini, Alessio; Salazar, Jorge L.; Lebron, Rodrigo M.; Cheong, Boon Leng

doi:10.1175/jtech-d-17-0083.1

Cited by 9 publications

(11 citation statements)

References 20 publications

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“…Hence, the attenuation of Z HH from the WRE can be derived by examining the excess of estimated Z HH biases from the systematic bias. On the other hand, the WRE of Z DR measurements depends on the forms in which the rain accumulates on the radome [37][38][39][40][41]. The forms could be droplets, rivulets, or non-uniform film and cause diverse WREs of Z DR .…”

Section: Z Hh Systematic Bias and The Wre Correctionmentioning

confidence: 99%

A Synthetic Quantitative Precipitation Estimation by Integrating S- and C-Band Dual-Polarization Radars over Northern Taiwan

Chen

Chang

Chang³

2021

Remote Sensing

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The key factors, namely, the radar data quality, raindrop size distribution (RSD) variability, and the data integration method, which significantly affect radar-based quantitative precipitation estimation (QPE) are investigated using the RCWF (S-band) and NCU C-POL (C-band) dual-polarization radars in northern Taiwan. The radar data quality control (QC) procedures, including the corrections of attenuation, the systematic bias, and the wet-radome effect, have large impact on the QPE accuracy. With the proper QC procedures, the values of normalized root mean square error (NRMSE) decrease about 10~40% for R(ZHH) and about 5~15% for R(KDP). The QPE error from the RSD variability is mitigated by applying seasonal coefficients derived from eight-year disdrometer data. Instead of using discrete QPEs (D-QPE) from one radar, the synthetic QPEs are derived via discretely combined QPEs (DC-QPE) from S- and C-band radars. The improvements in DC-QPE compared to D-QPE are about 1.5–7.0% and 3.5–8.5% in R(KDP) and R(KDP, ZDR), respectively. A novel algorithm, Lagrangian-evolution adjustment (LEA), is proposed to compensate D-QPE from a single radar. The LEA-QPE shows 1–4% improvements in R(KDP, ZDR) at the C-band radar, which has a larger scanning temporal gap (up to 10 min). The synthetic LEA-QPEs by combining two radars have outperformed both D-QPEs and DC-QPEs.

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Section: Z Hh Systematic Bias and The Wre Correctionmentioning

confidence: 99%

A Synthetic Quantitative Precipitation Estimation by Integrating S- and C-Band Dual-Polarization Radars over Northern Taiwan

Chen

Chang

Chang³

2021

Remote Sensing

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“…The transmission difference between these components is the main factor in many applications. For example in dual polarized weather radar systems, the main goal of active phased array antenna is to maintain a differential reflectivity (Z DR ) better than 0.1 dB, which is the transmission difference between H-and V-polarization components in logarithmic form [33], [34]. Transmission difference between H-and V-polarization of a radome creates a mismatch (CM dB ) in co-polarization radiation patterns of antenna systems.…”

Section: B Co-polarization Mismatchmentioning

confidence: 99%

An Ultra-Wide Band Radome for High-Performance and Dual-Polarized Radar and Communication Systems

2020

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This paper presents a new design methodology to develop a multi-layer radome for ultrawide-band, dual-polarized radar, and communication systems. In the proposed technique, a multi-layer radome is designed using a combination of A-sandwich structures, which are not used in conventional multi-layer radomes. In contrast with conventional radomes, this technique enables a substantial increase of bandwidth with a negligible change in the overall radome thickness. In addition, it provides excellent RF performance, thermal isolation, and mechanical strength. Three different multi-layer radomes for different bandwidths are designed. Parameters such as co-polarization mismatch and depolarization ratio are used to evaluate the proposed dual-polarized radome as a function of incident angle and frequency. To validate this new approach, a 5A-sandwich radome is designed to operate from 1 GHz to 14 GHz and its RF performance was evaluated by measuring S-parameters. The proposed radome is further investigated by measuring the radiation patterns of horn antennas at different bands (S-, C-, X-and Ku-bands) with and without the radomes. The measured losses recorded are below 0.5 dB with an absolute error less than 0.05 dB between the calculations and measurements. An S-band electronically scanned active phased array antenna is also used to evaluate the radome as a function of incident angles. In this case, the max recorded losses are below 0.4 dB and the absolute errors between the calculations and measurements are below 0.1 dB. The proposed technique and radome can be used in different applications such as surveillance systems, earth exploration satellite, aeronautical radio-navigation, and especially in dual-polarized weather radars that require a high polarization performance. INDEX TERMS A-sandwich, dual-polarized, multi-band, multi-layer, planar, radar, radome, ultra-wide band (UWB), wideband.

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“…However, the main beam's homogeneity with respect to differential power and phase is degraded with the radome [6]. The radio frequency performance of a radome is affected by different conditions, including dirtiness, wetness, and varying temperature [7]. For instance, rainfall or a continuous water layer on a radome may lead to transmission loss, attenuation, reflections, or cross polarization [8]- [10].…”

Section: Introductionmentioning

confidence: 99%

“…In this manuscript, the models of photogrammetry system and total station we carried were not supported, so this function could not be directly used. (7) If only a total station were used for observation, not only would the efficiency be reduced due to the excessive number of observation marks, but also when the antenna is at a high pitch angle, the total station could not directly observe the points on the antenna surface due to the narrow space in the radome.…”

Section: Introductionmentioning

confidence: 99%

A Method for Rapid Measurement of the Deformation and Spatial Attitude of Large Radar Antennas Inside Radomes

Guan

Cheng

2021

IEEE Access

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It is challenging to measure, analyze, and control the deformation and space attitude of antennas in narrow radomes through geometric measurement to ensure the accuracy of phased array radar application. In this manuscript, a method for rapid measurement of antennas by adopting the combination of photogrammetry system, laser tracker and total station was proposed. The photogrammetric method was used with a homemade auxiliary tool to measure and calculate the antenna's deformation under different temperatures and pitch angles. Mapping relations between the instrumental coordinate systems of photogrammetry system, laser tracker and total station were established through common points, including target balls and reflectors. Coordinates of mark points on antenna surface were converted from photogrammetric coordinate system to laser tracker's and total station's coordinate system. Thus, antenna's pitch angles relative to the local horizontal plane and deflection angles relative to the north of the engineering coordinate system were calculated. Planar fitting, coordinate transformation and space attitude calculation were all carried out in the Spatial Analyzer (SA) software. The photogrammetric method detected the antenna's gravitational deformation sensitively, the maximum Root Mean Square Residual (RMSR) of the reference length was 54 µm, and that of the mark points was 59 µm, which was stably in line with its nominal accuracy. Deviations caused by coordinate transformation had no significant effect on the calculation of antenna's spatial attitude, for the maximum deviation between the converted and measured coordinates in laser tracker's coordinate system was 0.139 mm, and that in total station's coordinate system was 1.037 mm, both of which were within reasonable limits of the derived theoretical maximum deviations between different instruments. As a result, the maximum deviation between the calculated value and servo system's nominal value of antenna's pitch angle was 59.4 , and that of antenna's deflection angle was 91.87 . This method's efficiency was greatly improved by about ten times compared with traditional methods through statistics and estimates.

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A Novel Instrument for Real-Time Measurement of Attenuation of Weather Radar Radome Including Its Outer Surface. Part I: The Concept

Cited by 9 publications

References 20 publications

A Synthetic Quantitative Precipitation Estimation by Integrating S- and C-Band Dual-Polarization Radars over Northern Taiwan

A Synthetic Quantitative Precipitation Estimation by Integrating S- and C-Band Dual-Polarization Radars over Northern Taiwan

An Ultra-Wide Band Radome for High-Performance and Dual-Polarized Radar and Communication Systems

A Method for Rapid Measurement of the Deformation and Spatial Attitude of Large Radar Antennas Inside Radomes

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