Applicability analysis of Dual-Polarization Weather Radar's Four Volume Coverage Patterns

Applicability analysis of Dual-Polarization Weather Radar's Four Volume Coverage Patterns | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Applicability analysis of Dual-Polarization Weather Radar's Four Volume Coverage Patterns Lin Ma, Diya Zhang, Shi Zheng, Wen Yao, Jing Zhang, Jiusong Wang, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9275613/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 10 You are reading this latest preprint version Abstract Aiming at the problem that China's current Volume Coverage Pattern (VCP) of VCP21D has insufficient vertical sampling below 5° elevation angle, and there is a detection gap nearby, four new VCPs (VCP12D, VCP212D, VCP215D, and VCP35D) were developed based on the WSR-88D VCP framework. Testing was conducted using the Yingkou dual-polarization weather radar. The results indicate that: (1) The four new VCPs exhibit basically consistent detection sensitivity, data quality, and ground clutter suppression capability with the existing VCP21D, suitable for business application. (2) Compared with VCP11D, the severe convective detection modes (VCP12D and VCP212D) enhance lower-level vertical resolution, the scanning time is reduced from 5 minutes to 4 minutes, thereby improving detection performance for rapidly evolving severe convective storms. (3) Relative to VCP21D, the non-severe convective precipitation mode (VCP215D) increases the number of detection elevation angles by 6 layers. This allows for a more comprehensive and detailed characterization of echo structural features and storm top height. (4) In comparison with VCP31D, the clear-air mode (VCP35D) has a slightly smaller detection range but higher spatiotemporal resolution, presenting significant superiority in clear-air detection. (5) The new VCPs have increased the maximum unambiguous velocity. Earth and environmental sciences/Climate sciences Earth and environmental sciences/Natural hazards dual-polarization weather radar Volume Coverage Pattern (VCP) sensitivity vertical detection Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 1. Introduction The detection performance of weather radars is affected by multiple factors. Maddox et al noted that different Volume Coverage Patterns (VCPs) of weather radars differ in scanning elevation angles, radar beam widths, and echo coverage ranges, and that VCPs determine the achievable detection accuracy 1 . Witt employed two WSR-88D radars configured with VCP11 and VCP21, respectively, to track and observe the same storm, and identified significant discrepancies in the resulting radar products 2 . The initial volume scan strategy of the WSR-88D defined four VCPs 3 , including two clear-air modes (VCP32 and VCP31) and two precipitation modes (VCP21 and VCP11). The 1998 version introduced several new scanning modes and parameter settings—including Super Resolution Volume Scan and Storm Attribute Identification—to enhance the quality and resolution of radar data 4 . For rapidly evolving severe convective storms (e.g., downbursts and tornadoes), the WSR-88D Radar Operations Center (ROC) and the U.S. National Severe Storms Laboratory (NSSL) have developed and validated several experimental scanning strategies (VCP12 and VCP121) 5 , 6 . Versions 9 and 10 of the WSR-88D scanning strategy include 2 clear-air modes (VCP32, VCP31) and 7 precipitation modes in total. 7 . VCP121 was modified in Version 10 and later replaced by VCP112 in Version 19 (2020) 8 . Selecting the optimal volume scan mode is critical for accurate severe weather forecasting and early warning, but the 7 precipitation modes create challenges for mode selection 9 , 10 . The dynamic scanning method was first implemented in operations in 2012. AVSET (Automated Volume Scan Evaluation and Termination), functions by monitoring reflectivity intensity and coverage across all elevation angles during Volume Coverage. It dynamically terminates the Volume Coverage process when echo reflectivity at the scanned elevation angle does not meet preset criteria 11 . This adaptive approach shortens Volume Coverage time and reduces product update intervals. AVSET has been enabled by default since 2012, with manual deactivation available if needed 7 . Two upgraded dynamic scanning versions were introduced in 2014–2015 and 2018–2019 respectively: SAILS (Supplemental Adaptive Intra-Volume Low-Level Scan) 12 and MRLE (Mid-volume Rescan of Low-level Elevations) 13 . Forecasters at National Weather Service (NWS) Weather Forecast Offices (WFOs) can select the appropriate version based on specific detection requirements. Since the nationwide deployment of weather radars in China, the VCP21 precipitation mode has served as the primary volume scanning configuration 14 , 15 . However, a single volume scanning mode has inherent limitations when detecting diverse weather systems. In response, Chinese meteorological researchers have conducted targeted analytical and experimental studies to optimize radar volume scanning modes and improve overall detection quality. Liu Yingjun conducted a comparative study of volume scanning modes for China’s new-generation weather radars 16 . They identified the similarities and differences between VCP11 and VCP21 in capturing specific weather scenarios, clarified the weather types each mode is best suited for, and emphasized that significant discrepancies arise between the products of VCP11 and VCP21 when severe convective weather occurs near the radar—with VCP11 demonstrating superior detection performance in such cases. Given the pivotal role of new-generation weather radars in nowcasting and severe weather warning operations, Zhang et al proposed incorporating supplementary observation modes such as Plan Position Indicator (PPI) and Range Height Indicator (RHI) to enhance radar detection capabilities 17 . This study draws on the volume coverage mode of WSR-88D and adjusts the antenna speed based on the performance indicators of domestic radar antenna azimuth. By configuring pulse repetition frequency and sampling parameters, four new volume scanning modes are developed (namely VCP12D, VCP212D, VCP215D, and VCP35D, where the "D" denotes dual-polarization). Scanning tests were then conducted at the Yingkou Weather Radar Station, aiming to expand the effective detection coverage of the dual-polarization weather radar—with a particular focus on enhancing detection performance in areas beyond 100 km from the radar. The results show that the new VCPs have improved in terms of low-level vertical resolution, scanning time, echo characteristics, and maximum unambiguous speed. 2. Materials and methods 2.1 VCP12D and VCP212D VCP12D and VCP212D are intense convection modes, upgraded from VCP11D. In comparison with VCP11D, VCP12D and VCP212D still maintain 14 scanning elevation angles, but with 2 upper-level elevation angles reduced and 2 lower-level elevation angles added. Appropriately increasing the density of lower-level detection elevation angles can effectively improve the detection performance at locations far from the radar, enabling more detailed detection data beyond 100 km from the radar. Meanwhile, the maximum unambiguous velocity of the radar has been enhanced: for VCP12D and VCP212D, the maximum unambiguous velocity at upper-level elevation angles (12.5°, 15.6°, 19.5°) has been increased to 33.36 m/s; for VCP212D, that at lower-level elevation angles (0.5°, 0.9°, 1.3°) has been raised to 28.47 m/s (whereas the maximum unambiguous velocity at low elevation angles for VCP11D and VCP12D is 26.38 m/s). For the three lowest elevation angles (0.5°, 0.9°, 1.3°), the VCP12D mode employs the CS/CD separated sampling scheme, whereas the VCP212D mode adopts the CS/SZCD separated sampling scheme. The SZ phase coding and random phase coding techniques, imported from the United States, are applied to the 0.5° and 1.5° elevation angles with the objective of effectively reducing the area of range folding regions (i.e., purple-colored areas) in radial velocity maps. At the 1.8° elevation angle—largely free from ground clutter interference—both modes employ the B (batch) alternating scanning scheme (as hereafter). Both VCP12D and VCP212D complete 17 sweeps across 14 elevation angles in approximately 4 minutes. The primary distinction resides in the number of velocity pulses: at the three lowest elevation angles, VCP12D utilizes 40 velocity samples, while VCP212D employs 64 samples. In general, a greater number of samples is associated with improved radar detection quality. 2.2 VCP215D The VCP215D mode, categorized as a general precipitation mode, represents an upgraded version of VCP21D. It incorporates 2 additional low-level, 2 mid-level, and 2 upper-level elevation angles. For the three lowest elevation angles, the CS/SZCD separated sampling scheme is employed, and the mode completes 18 sweeps across 15 elevation angles within 6 minutes and 7 seconds. Compared with the VCP21D mode, VCP215D incorporates 6 additional scanning elevation angles, thereby achieving a marked enhancement in vertical detection resolution. Furthermore, relative to VCP21D, the maximum unambiguous velocity of VCP215D at upper-level elevation angles (10.0°, 12.0°, 14.0°, 16.7°, 19.5°) is increased to 33.36 m/s—whereas for VCP21D, the maximum unambiguous velocity at elevation angles above 9.9° is 30.73 m/s. At low-level elevation angles (0.5°, 0.9°, 1.3°), VCP215D’s maximum unambiguous velocity is raised to 28.47 m/s, in contrast to 26.38 m/s at the lowest elevation angles of VCP21D. 2.3 VCP35D The VCP35D mode is clear-air mode and an upgraded version of the VCP31D mode, incorporates 2 additional lower-level elevation angles and 2 additional mid-level elevation angles. For the three lowest elevation angles, the CS/SZCD separated sampling scheme is employed, and it completes 12 sweeps across 9 elevation angles in 6 minutes and 50 seconds. Compared with the VCP31D mode, the VCP35D mode, on the one hand, reduces the scanning time and enhances detection timeliness; on the other hand, through adjustments to scanning elevation angles, it enables more detailed characterization of structural features across radar layers. Additionally, relative to the VCP31D mode, its maximum unambiguous velocity is increased from 11.6 m/s to 26.38 m/s. 3. Results 3.1 Differences in the Sensitivity of Base Data Radar sensitivity refers to the minimum signal detectable by radar when detecting different distances. SYSCAL is a target constant for radar linear channel gain calibration, which can comprehensively reflect the static and dynamic measurement biases of radar in reflectivity factor measurement 18 . In the following, the detection test data of two weather processes with different characteristics—cold vortex severe convection on September 10–11, 2021, and blizzard on November 7–9, 2021—are used for sensitivity analysis. The radar sensitivity of base data from the September 10–11, 2021 process was analyzed. Base data from 23:01 to 23:22 on September 10 (Beijing Time, hereinafter the same) were selected for sensitivity calculation. During this period, five VCPs, namely VCP11D, VCP12D, VCP21D, VCP212D, and VCP215D, were sequentially used for detection tests (Fig. 1 a). The minimum sensitivity values of these five VCPs at 50 km from the radar were − 8.0 dBz, -9.0 dBz, -7.5 dBz, -8.5 dBz, and − 8.0 dBz, respectively, with little difference among the values. VCP12D exhibited the highest sensitivity, followed by VCP212D, then VCP11D and VCP215D, while VCP21D showed the lowest sensitivity. During this detection period, SYSCAL remained consistently 40.2 dB, and the detection of reflectivity was very stable during the switching of the five detection modes. The radar sensitivity of base data from the November 7–9, 2021 process was analyzed. Base data from 07:35 to 08:28 on November 8 were selected for sensitivity calculation. During this period, four VCPs, namely VCP215D, VCP21D, VCP31D, and VCP35D, were used for detection tests (Fig. 1 b). The minimum sensitivity values of these four VCPs at 50 km from the radar were − 8.0 dBz, -8.0 dBz, -17.5 dBz, and − 8.0 dBz, respectively. VCP215D, VCP21D, and VCP35D exhibited consistent sensitivity, while VCP31D showed the highest sensitivity. The SYSCAL values for VCP215D, VCP21D, and VCP35D were all 39.7 dB, whereas that for VCP31D was 34.9 dB. During this detection period, reflectivity detection remained very stable when switching among VCP215D, VCP21D, and VCP35D. The reason for the differences in sensitivity and SYSCAL between VCP31D and the other patterns lies in the fact that VCP31D uses long pulses (with a pulse width of 4.5 µs), while the other patterns use short pulses (with a pulse width of 1.57 µs). Different color blocks in Fig. 1 indicate differences in the amount of detected data. By comparing VCP215D and VCP21D in the two processes, VCP215D has more detection elevations, resulting in a significantly greater amount of detected data than VCP21D. More data can more accurately reflect the echo morphology and fine structural characteristics. 3.2 Detect Vertical Structural Difference Differences in radar products among different VCPs mainly lie in the differences in vertical detection accuracy caused by the density of detection elevations, and are also related to the number of samples and PRF. The detection effect of radar on storms is directly related to the relative position of the storm with respect to the radar 19 , 20 . Taking the Yingkou weather radar as an example, the radar blind cone has a significant impact near the radar. At 25 km from the radar, the maximum data height achievable in the vertical direction is 9 km (i.e., the detection height at a 19.5° elevation angle, hereinafter the same). For vigorous severe convective storms, the radar can only detect their lower and middle-level structural characteristics. At 50 km from the radar, data at a height of 18 km can be obtained in the vertical direction. At this distance, most of the radar's scanning elevations can pass through convective storms, enabling a relatively complete reflection of their structural characteristics. High elevations can detect the storm tops, while middle and low elevations can well reflect the status of the lower and middle parts of thunderstorms. VCP21D has detection gaps in the upper levels, but the new patterns (VCP12D, VCP212D, and VCP215D) with more detection elevations can accurately depict the storm structural characteristics, which is conducive to detecting mesocyclones, shear, convergence, divergence and other information in radial velocity products. With the increase in distance from the radar, the number of effective detection elevations gradually decreases. At 200 km from the radar, the height of middle and high elevations above the ground is much higher than the vertical extension height of thunderstorms. Generally, only elevations below 4° have effective detection at this distance (the 4.3° elevation at 200 km is approximately 17.7 km above the ground). The increased low-level elevations of the new patterns (VCP12D, VCP212D, VCP215D) exhibit their detection advantages. The traditional patterns (VCP11D, VCP21D, VCP31D) only have 2–3 effective detection elevations at this distance (4–5 effective detection elevations for extremely vigorous convective cells), while VCP12D, VCP212D, and VCP215D can have 4–6 effective detection elevations (6–8 effective detection elevations for extremely vigorous convective cells). Figure 2 shows the schematic diagrams of VCP21D and VCP215D. It can be seen that in vertical detection, the vertical detection performance of VCP215D is superior to that of VCP21D both near and far from the radar. 3.3 Differences in Clutter Suppression Capability Clutter is divided into normal clutter caused by ground objects such as mountains and high towers under the normal propagation of radar beams, and abnormal clutter caused by superrefraction of radar beams under special meteorological conditions. The filtering method used by the Yingkou weather radar is two-dimensional Doppler point clutter filtering, which refers to the two-dimensional (3×3 azimuth and range) point clutter filtering applied to Doppler data. Radar base data reflectivity products include pre-filtered reflectivity (Total Reflectivity, data type: dBT) and post-filtered reflectivity (Reflectivity, data type: dBz). The filtering effect can be represented by comparing the differences between the dBT and dBz products of the corresponding pattern—specifically, using the difference between the area occupied by each reflectivity level in the dBT product and that in the dBz product at the 0.5° elevation angle. This comparison is then used to further analyze the differences in clutter suppression capability among different VCPs. Clutter exhibits differences under different seasons and meteorological conditions. Figure 3 shows the comparison of filtering effects (i.e., the difference between the area of pre-filtered reflectivity and that of post-filtered reflectivity) among various VCPs during three events: September 10, 2021 (a), June 10, 2023 (b), and November 8, 2021 (c). The same VCP exhibits significant differences in filtering results among the three weather events. However, during the same event, there is little difference in filtering effects among different VCPs, with basically consistent variation trends—indicating that the differences in clutter suppression capability among different VCPs are insignificant. 4. Discussion VCP11D, VCP12D, and VCP212D are severe convective modes; VCP21D and VCP215D are general precipitation modes; and VCP31D and VCP35D are clear-air modes. In the following, combined with typical cases, we analyze the differences in products among different VCPs, the causes of these differences, and the superiority of the new VCP modes. 4.1 Case Study of Severe Convection on September 10, 2021 From September 10 to 11, 2021, affected by the Northeast Cold Vortex, severe convective weather occurred in the central and eastern parts of Liaoning Province. The maximum rainfall reached 194.5 mm, and the maximum hourly precipitation was 79.1 mm. Local areas of Benxi, Dandong, Yingkou, and Liaoyang experienced instantaneous gales of magnitude 8–10, while local areas of Anshan, Dandong, Yingkou, and Liaoyang witnessed large hailstones with a diameter of 3–5 cm. Starting at 20:00 on the 10th, convective echoes generated over the northern coastal area of Yingkou and rapidly intensified into multi-cell storms. Some multi-cell storms moved northeastward and further intensified into supercell storms, which successively affected Yingkou, Anshan, and Liaoyang, causing severe wind and hail weather in these three regions. From 23:01 to 23:22, five VCPs—VCP11D, VCP12D, VCP21D, VCP212D, and VCP215D—were continuously used for detection tests. The aforementioned supercell storm was selected for the applicability analysis of detection products from different VCPs. Figure 4 shows the radar product detection results of the five VCP scans for this supercell. The first row presents the distribution changes of the supercell at the 0.5° elevation angle, while Rows 2–5 display the cross-sectional structures along the position indicated by the yellow solid line on the 0.5° horizontal plane. At 23:01, VCP11D was used. The main echo was 35–55 km away from the radar, and thunderstorm echoes were detected by all 14 detection elevations of the pattern. Among them, the vertical extension height of 30 dBz was 11 km (at a 14.0° detection elevation), while the two highest elevations (16.7° and 19.5°) showed weak echoes with an intensity of -5ཞ5 dBz, which is a "false cusp" feature caused by side lobe echoes. At 23:07, VCP12D was adopted. The main echo was 35–55 km from the radar, and thunderstorm echoes were captured by all 14 detection elevations of the pattern. The vertical extension height of 30 dBz was 11 km (at a 14.0° detection elevation), and the echo intensity at the two highest elevations (15.6° and 19.5°) ranged from − 5 to 10 dBz. At 23:11, VCP21D was used. The echo distance from the radar was 35–65 km, and thunderstorm echoes were detected by all 9 detection elevations of the pattern. Among them, the vertical extension height of 30 dBz was 11 km (at a 9.9° detection elevation), while only a small amount of weak echoes were observed at the two highest elevations (14.6° and 19.5°) with an intensity of -5ཞ5 dBz. On the vertical cross-section, an obvious echo gap can be seen on the side far from the radar. This gap is caused by the inability to perform interpolation due to the presence of detection gaps between the radar beams at upper elevations, leading to the incomplete presentation of the echo's vertical structure. Meanwhile, due to the small number of elevations in this VCP, a dome-like structural characteristic appeared at 5–10 km during the vertical cross-section interpolation. By comparing with the four adjacent scans (the two before and two after), it can be judged that this structural characteristic has deviations. At 23:17, VCP212D was used. The echo was 40–75 km away from the radar, and thunderstorm echoes were detected by all 14 detection elevations of the pattern. Among them, the vertical extension height of 30 dBz was 12 km (at a 10.0° detection elevation), and the echo intensity at the three highest elevations (12.5°, 15.6°, and 19.5°) ranged from − 5 to 20 dBz. Compared with VCP21D at the previous time, although the storm cell was farther from the radar at this time, the addition of a 12.5° detection elevation improved the continuity of vertical detection, thus capturing a more complete vertical structure of the storm. At 23:22, VCP215D was adopted. The echo was 45–77 km away from the radar, and thunderstorm echoes were detected by all 15 detection elevations of the pattern except the topmost one (19.5°). The vertical extension height of 30 dBz was 12 km (at a 10.0° detection elevation), and the echo intensity at the second-highest two elevations (14.0° and 16.7°) was − 5ཞ5 dBz. The vertical structure of the storm detected by the radar at this time was still relatively complete. Comparing the vertical cross-sections of the average radial velocity (V), differential reflectivity (ZDR), correlation coefficient (CC), and specific differential phase (KDP) products among the five VCPs, similarly, VCPs with more scanning elevations exhibit better product continuity. In particular, VCP212D, VCP12D, and VCP215D have more low-level elevations, presenting more detailed low-level echo structures. Likewise, more scanning elevations can better reflect the storm top height, which is one of the characteristic indicators of the development intensity of thunderstorm cells. Echo Top Height (TOPS) plots refer to the height of the highest elevation where the reflectivity factor is ≥ 18 dBz. It can be seen from the TOPS plots of the five time periods in Fig. 4 that due to the fewer scanning elevations, VCP21D shows an obvious "stepped" echo morphology, and the detected echo top height is significantly discontinuous and lower than that of the other four VCPs, while VCP215D achieves the best detection performance. 4.2 Case Analysis of a Heavy Snowstorm Event on November 8, 2021 From November 7 to 9, 2021, affected by the Northeast Cold Vortex and the strong development of the surface cyclone, Liaoning Province experienced a rare combination of extreme heavy snowstorm, snow-rain freezing, cold wave, and gale weather in history. The average precipitation at 62 national meteorological observation stations across the province was 41.1 mm, with 39 stations recording extreme heavy snowstorm. The snow-rain process was accompanied by instantaneous gales of magnitude 11, a sharp temperature drop of more than 16 ℃, freezing, and weak thunder and lightning. Four VCPs—VCP215D, VCP21D, VCP31D, and VCP35D—were used for detection tests during this event. The following is an analysis of the radar products from VCP215D at 07:35, VCP35D at 07:50, VCP21D at 08:05, and VCP31D at 08:17 on the 8th. During this period, the system developed stably with little change in echo morphology, exhibiting strong comparability. Among the four VCPs, VCP215D, VCP21D, and VCP35D utilize short pulses, while VCP31D employs long pulses. Figure 5 presents a comparison chart of the reflectivity factor area by intensity level at the 0.5° elevation angle for the four VCPs. By counting the detected data with intensity greater than − 5 dBz, it can be observed from the figure that the data distribution trends of VCP215D, VCP21D, and VCP35D are basically consistent. VCP31D detects significantly more data in the weak echo region (-5ཞ5 dBz), which is attributed to the longer dwell time of its pulse beam and the larger volume of sampled data. Meanwhile, the amount of strong echo data (≥ 65 dBz) detected by VCP31D is also higher than that of the other VCPs, and clutter is more prominent in VCP31D's products. By comparing the reflectivity charts at 0.5° elevation (the upper part of Fig. 6 ), it can also be observed that the echo area of VCP31D is significantly larger than that of other VCPs, enabling it to better depict the outline of the cloud system. On the vertical cross-sections of reflectivity (Fig. 5 ), VCP31D has a maximum elevation angle of 4.5° and the largest scope of the echo blind cone area; followed by VCP35D with a maximum elevation angle of 6.4°; both VCP215D and VCP21D have a maximum elevation angle of 19.5° and the smallest blind cone area. Regarding echo continuity, VCP215D achieves the best performance. On the average radial velocity charts, different VCPs use different PRF at various elevations, resulting in distinct maximum unambiguous velocities. Taking the 0.5° elevation as an example: for VCP21D and VCP35D, the maximum unambiguous velocity is 26.38 m/s with an effective detection range of 148 km; VCP215D has a maximum unambiguous velocity of 28.47 m/s and an effective detection range of 137 km; for VCP31D, the PRF is 322 s⁻¹, and its detectable maximum unambiguous velocity is only 8.38 m/s, while the effective detection range reaches 466 km. It can be observed from the radial velocity chart at 0.5° elevation (the lower part of Fig. 7) that the average radial velocity range of VCP31D is significantly larger than that of other VCPs. However, it also exhibits obvious velocity aliasing—even second-order aliasing. VCP35D is an upgraded version of VCP31D. When compared with VCP31D, VCP35D has a slightly smaller detected data range and slightly weaker weak echo detection capability. However, it features a shorter scanning time (3 minutes less than VCP31D), more scanning elevations, and a larger maximum unambiguous velocity, exhibiting obvious advantages in clear-air echo detection. 5. Conclusion To address the issues of insufficient vertical sampling below 5° elevation and existing detection gaps in the vicinity for the VCP21D volume coverage pattern, drawing on the volume scan modes of the WSR-88D radar, has developed four new volume coverage patterns (VCP12D, VCP212D, VCP215D, and VCP35D) that differ from the current operational modes. Operational tests were conducted using the Yingkou dual-polarization weather radar, and comparative analyses of the test products were performed. The conclusions are as follows: (1) At 50 km, the minimum sensitivity, data quality, and clutter suppression capability of the four new VCPs are basically consistent with those of VCP21D. They meet the operational performance indicators and can be applied in operational practice. (2) Compared with VCP11D, VCP12D and VCP212D have improved low-level vertical resolution, enabling them to obtain more detailed detection data beyond 100 km from the radar. Meanwhile, the scanning time is shortened from 5 minutes to 4 minutes, resulting in better detection performance for rapidly developing severe convective storms. With short detection cycles and more elevations, VCP12D and VCP212D are suitable for application in severe convective weather processes. (3) Compared with VCP21D, VCP215D has an additional 6 detection elevations, which allows for more continuous vertical detection products. It can display more complete and detailed echo structural characteristics on cross-sections and calculate the storm top height more accurately. Additionally, its detection time is comparable to that of VCP21D, demonstrating obvious advantages. VCP215D can replace VCP21D in the detection of severe convective weather and large-scale snow-rain weather processes. (4) Although VCP35D has a slightly smaller detected data range than VCP31D, it features shorter scanning time, more detection elevations, and higher spatiotemporal resolution of products, showing significant detection advantages. (5) Compared with the original modes, all four new VCPs (VCP12D, VCP212D, VCP215D, and VCP35D) have improved maximum unambiguous velocity. Specifically, the maximum unambiguous velocity of VCP12D, VCP212D, and VCP215D can reach 33.36 m/s at upper levels (above 10°); VCP212D and VCP215D have an improved maximum unambiguous velocity of 28.47 m/s at low levels (0.5°–1.3°); and VCP35D has an overall improved maximum unambiguous velocity of 26.38 m/s throughout the entire layer. It should be noted that to ensure the quality of normal operational detection and enhance the comparability of different products, the operational experiment of the new VCPs adopted a method of continuously switching between the new and original VCPs. Specifically, during a certain period of a single weather process, continuous switching of volume scan modes was performed to obtain relatively continuous comparative data. For a more comprehensive evaluation of the new VCPs, continuous and complete detection of a single weather process using the same new VCP should be conducted. Meanwhile, further research should be carried out on the matching between the new VCPs and the existing radar algorithms. Declarations Author Contributions: All authors have contributed to this article. Lin Ma is responsible for conceptualizing experimental ideas and analyzing data, Diya Zhang is responsible for writing and revising articles, Shi Zheng is responsible for revising articles, Jing Zhang is responsible for designing experimental plans, and Wen Yao is responsible for implementing experiments and analyzing results. Jiusong Yuan and Dong Wang are responsible for analyzing results. Funding: This research received no external funding. Data Availability Statement: Due to privacy protection of meteorological data, the research data involved in this article should not be disclosed. If you are interested in this research, please contact [email protected] . Acknowledgments: The authors would like to express their gratitude to Liaoning Meteorological Equipment Support Center and Yingkou Meteorological Service for technical support. We also appreciate the valuable feedback from all reviewers during the preparation of this manuscript. Conflict of interest : The author declares that there are no conflicts of interest regarding the publication of this article. All research activities were conducted without any influence from personal or external interests that could bias the results. References Maddox, R. et al. Echo height measurements with the WSR-88D: Use of data from one versus two radars. Weather forecasting 14 , 455-460, doi:https://doi.org/10.1175/1520-0434(1999)014,0455:EHMWTW.2.0.CO;2 (1999). 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Yingjun, L., Songshan, G., Yuhua, Z., Shengshou, Z. & Zejun, D. Comparison of CINRAD/SA Volume Coverage Patterns on Algorithms Output. Meteorological Monthly 32 , 44-50 (2006). Peiyuan, Z., Hongping, Y. & shaoping, H. Applications of New Generation Weather Radar to Nowcasting and Warning of Severe Weather. Meteorological Monthly 34 , 3-11 (2008). Jianfeng, Q., Xiaoyu, X., Ming, T., Shengchao, C. & Hong, C. SYSCAL Based On line Calibration Technique of Weather Radar Reflectivity Factor. Meteorological Science and Technology 45 , 962-967 (2017). Dianli, G., Junjian, Z., Qufeng, L. & Jian, G. Radar Observation Analysis of Severe Hailstorm and Tornado Caused by a Supercell in Autumn. Meteorological Monthly 50 , 561-576, doi:10.7519/j.issn.1000-0526.2023.110101 (2024). Wen, Y. et al. Dual-Polarization Weather Radar Echo Characteristics of Avian Activities in the Liaohe River Delta Wetland. Meteorological Monthly 48 , 1162-1170, doi:10.7519/j.issn.1000-0526.2022.041401 (2022). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 27 Apr, 2026 Reviews received at journal 24 Apr, 2026 Reviews received at journal 13 Apr, 2026 Reviewers agreed at journal 09 Apr, 2026 Reviewers agreed at journal 07 Apr, 2026 Reviewers invited by journal 06 Apr, 2026 Editor invited by journal 06 Apr, 2026 Editor assigned by journal 01 Apr, 2026 Submission checks completed at journal 01 Apr, 2026 First submitted to journal 31 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9275613","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":620649976,"identity":"c9b593c8-6541-4779-84c7-c4ad343a6371","order_by":0,"name":"Lin Ma","email":"","orcid":"","institution":"Liaoning Meteorological Equipment Support Center","correspondingAuthor":false,"prefix":"","firstName":"Lin","middleName":"","lastName":"Ma","suffix":""},{"id":620649980,"identity":"fda22527-542f-4d3f-ba3f-5a65472ceeba","order_by":1,"name":"Diya Zhang","email":"","orcid":"","institution":"Liaoning Meteorological Equipment Support Center","correspondingAuthor":false,"prefix":"","firstName":"Diya","middleName":"","lastName":"Zhang","suffix":""},{"id":620649982,"identity":"6db1f2fc-1cbf-4b4b-898b-e1505de623a9","order_by":2,"name":"Shi Zheng","email":"","orcid":"","institution":"Liaoning Meteorological Equipment Support Center","correspondingAuthor":false,"prefix":"","firstName":"Shi","middleName":"","lastName":"Zheng","suffix":""},{"id":620649983,"identity":"b38ddf51-a842-46e4-af9c-fdfd2a73e0ee","order_by":3,"name":"Wen Yao","email":"","orcid":"","institution":"Yingkou Meteorological Service","correspondingAuthor":false,"prefix":"","firstName":"Wen","middleName":"","lastName":"Yao","suffix":""},{"id":620649984,"identity":"586eaeef-9458-4ac4-a8f2-aa8978beb470","order_by":4,"name":"Jing Zhang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA00lEQVRIie3RoQoCQRDG8TmEtQxe3UO4C2Zh4UAQxGfZRTCJxWJzxapdwYcQBPPIwKXTfFUE0wV9AbFqurUJ7r//YD4GwOf7wQQwkXnKWVhfkBtpBJmhu+jpaJlpNxLX8tZxLYZaFSPleJjIgRF5HNnRoyihH7dtFcETMUqehHDad7cwSDtUReRZMyoONvPVoYlA5lBJklIxag52jDdHArk6rmlodhkKV5JpetheGi1F2t0qhy2JZb4bK+MwuV6KctqPK8lHEh1f806+FT6fz/cXvQD2H0kg5vcGUAAAAABJRU5ErkJggg==","orcid":"","institution":"Yingkou Meteorological Service","correspondingAuthor":true,"prefix":"","firstName":"Jing","middleName":"","lastName":"Zhang","suffix":""},{"id":620649985,"identity":"e2d20974-60cb-44b8-9368-9296ed033e28","order_by":5,"name":"Jiusong Wang","email":"","orcid":"","institution":"Yingkou Meteorological Service","correspondingAuthor":false,"prefix":"","firstName":"Jiusong","middleName":"","lastName":"Wang","suffix":""},{"id":620649987,"identity":"c115cec6-dd78-48d8-9812-06eba280d3b6","order_by":6,"name":"Dong Wang","email":"","orcid":"","institution":"Yingkou Meteorological Service","correspondingAuthor":false,"prefix":"","firstName":"Dong","middleName":"","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2026-03-31 06:53:48","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9275613/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9275613/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106765858,"identity":"5a799cca-f384-429c-b8ab-686702fb4d9e","added_by":"auto","created_at":"2026-04-13 09:32:19","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":862884,"visible":true,"origin":"","legend":"\u003cp\u003eRadar sensitivity distribution for the base data on September 10, 2021 (a), and November 8, 2021 (b).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9275613/v1/2d7d59573f64b7c730a103a3.png"},{"id":106960099,"identity":"9ae30cb4-e556-4a14-b10f-4480f9187c0e","added_by":"auto","created_at":"2026-04-15 09:18:54","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":208487,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of VCP21D and VCP215D.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9275613/v1/868004f39d3d84d1b6752824.png"},{"id":106994109,"identity":"77eb8b7b-fe2d-4252-8e72-88e76bf8bbf4","added_by":"auto","created_at":"2026-04-15 15:04:10","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":176472,"visible":true,"origin":"","legend":"\u003cp\u003eFiltering results of different VCPs for three events on September 10, 2021 (a), June 10, 2023 (b), and November 8, 2021 (c).\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9275613/v1/a440acb857b2e9ea7e54069c.png"},{"id":106765861,"identity":"f37e78a7-0444-48e2-a1f9-462fd786a0ee","added_by":"auto","created_at":"2026-04-13 09:32:19","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1040723,"visible":true,"origin":"","legend":"\u003cp\u003eContinuous radar products from five different VCPs between 23:01 and 23:22 on September 10, 2021.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-9275613/v1/0a4f6c6ca08bbf7aec9fbc86.png"},{"id":106765863,"identity":"0e8aa8b7-0c04-45e9-9b87-2ee96e025152","added_by":"auto","created_at":"2026-04-13 09:32:19","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":65548,"visible":true,"origin":"","legend":"\u003cp\u003eArea comparison of reflectivity factors at 0.5° elevation angle for four different VCPs between 7:35 and 8:17 on November 8, 2021.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-9275613/v1/29908a049b578b961c8d588c.png"},{"id":106765862,"identity":"db695fda-9e28-4e3b-89fd-aa36aa80cb88","added_by":"auto","created_at":"2026-04-13 09:32:19","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":644094,"visible":true,"origin":"","legend":"\u003cp\u003eRadar Products from Four Different VCPs between 7:35 and 8:17 on November 8, 2021.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-9275613/v1/9a515cdf6ca2b45ef5372502.png"},{"id":106994899,"identity":"3826fcf3-9f77-4ad4-a678-b6fb015488f4","added_by":"auto","created_at":"2026-04-15 15:20:22","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3323002,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9275613/v1/02bece78-f085-428e-91b6-1d3fc3afd2cd.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Applicability analysis of Dual-Polarization Weather Radar's Four Volume Coverage Patterns","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThe detection performance of weather radars is affected by multiple factors. Maddox et al noted that different Volume Coverage Patterns (VCPs) of weather radars differ in scanning elevation angles, radar beam widths, and echo coverage ranges, and that VCPs determine the achievable detection accuracy \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. Witt employed two WSR-88D radars configured with VCP11 and VCP21, respectively, to track and observe the same storm, and identified significant discrepancies in the resulting radar products \u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. The initial volume scan strategy of the WSR-88D defined four VCPs \u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e, including two clear-air modes (VCP32 and VCP31) and two precipitation modes (VCP21 and VCP11). The 1998 version introduced several new scanning modes and parameter settings\u0026mdash;including Super Resolution Volume Scan and Storm Attribute Identification\u0026mdash;to enhance the quality and resolution of radar data \u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. For rapidly evolving severe convective storms (e.g., downbursts and tornadoes), the WSR-88D Radar Operations Center (ROC) and the U.S. National Severe Storms Laboratory (NSSL) have developed and validated several experimental scanning strategies (VCP12 and VCP121) \u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. Versions 9 and 10 of the WSR-88D scanning strategy include 2 clear-air modes (VCP32, VCP31) and 7 precipitation modes in total. \u003csup\u003e7\u003c/sup\u003e. VCP121 was modified in Version 10 and later replaced by VCP112 in Version 19 (2020) \u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eSelecting the optimal volume scan mode is critical for accurate severe weather forecasting and early warning, but the 7 precipitation modes create challenges for mode selection \u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. The dynamic scanning method was first implemented in operations in 2012. AVSET (Automated Volume Scan Evaluation and Termination), functions by monitoring reflectivity intensity and coverage across all elevation angles during Volume Coverage. It dynamically terminates the Volume Coverage process when echo reflectivity at the scanned elevation angle does not meet preset criteria \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. This adaptive approach shortens Volume Coverage time and reduces product update intervals. AVSET has been enabled by default since 2012, with manual deactivation available if needed \u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e. Two upgraded dynamic scanning versions were introduced in 2014\u0026ndash;2015 and 2018\u0026ndash;2019 respectively: SAILS (Supplemental Adaptive Intra-Volume Low-Level Scan) \u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e and MRLE (Mid-volume Rescan of Low-level Elevations) \u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Forecasters at National Weather Service (NWS) Weather Forecast Offices (WFOs) can select the appropriate version based on specific detection requirements.\u003c/p\u003e \u003cp\u003eSince the nationwide deployment of weather radars in China, the VCP21 precipitation mode has served as the primary volume scanning configuration \u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. However, a single volume scanning mode has inherent limitations when detecting diverse weather systems. In response, Chinese meteorological researchers have conducted targeted analytical and experimental studies to optimize radar volume scanning modes and improve overall detection quality. Liu Yingjun conducted a comparative study of volume scanning modes for China\u0026rsquo;s new-generation weather radars \u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. They identified the similarities and differences between VCP11 and VCP21 in capturing specific weather scenarios, clarified the weather types each mode is best suited for, and emphasized that significant discrepancies arise between the products of VCP11 and VCP21 when severe convective weather occurs near the radar\u0026mdash;with VCP11 demonstrating superior detection performance in such cases. Given the pivotal role of new-generation weather radars in nowcasting and severe weather warning operations, Zhang et al proposed incorporating supplementary observation modes such as Plan Position Indicator (PPI) and Range Height Indicator (RHI) to enhance radar detection capabilities \u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThis study draws on the volume coverage mode of WSR-88D and adjusts the antenna speed based on the performance indicators of domestic radar antenna azimuth. By configuring pulse repetition frequency and sampling parameters, four new volume scanning modes are developed (namely VCP12D, VCP212D, VCP215D, and VCP35D, where the \"D\" denotes dual-polarization). Scanning tests were then conducted at the Yingkou Weather Radar Station, aiming to expand the effective detection coverage of the dual-polarization weather radar\u0026mdash;with a particular focus on enhancing detection performance in areas beyond 100 km from the radar. The results show that the new VCPs have improved in terms of low-level vertical resolution, scanning time, echo characteristics, and maximum unambiguous speed.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 VCP12D and VCP212D\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eVCP12D and VCP212D are intense convection modes, upgraded from VCP11D. In comparison with VCP11D, VCP12D and VCP212D still maintain 14 scanning elevation angles, but with 2 upper-level elevation angles reduced and 2 lower-level elevation angles added. Appropriately increasing the density of lower-level detection elevation angles can effectively improve the detection performance at locations far from the radar, enabling more detailed detection data beyond 100 km from the radar. Meanwhile, the maximum unambiguous velocity of the radar has been enhanced: for VCP12D and VCP212D, the maximum unambiguous velocity at upper-level elevation angles (12.5\u0026deg;, 15.6\u0026deg;, 19.5\u0026deg;) has been increased to 33.36 m/s; for VCP212D, that at lower-level elevation angles (0.5\u0026deg;, 0.9\u0026deg;, 1.3\u0026deg;) has been raised to 28.47 m/s (whereas the maximum unambiguous velocity at low elevation angles for VCP11D and VCP12D is 26.38 m/s).\u003c/p\u003e \u003cp\u003eFor the three lowest elevation angles (0.5\u0026deg;, 0.9\u0026deg;, 1.3\u0026deg;), the VCP12D mode employs the CS/CD separated sampling scheme, whereas the VCP212D mode adopts the CS/SZCD separated sampling scheme. The SZ phase coding and random phase coding techniques, imported from the United States, are applied to the 0.5\u0026deg; and 1.5\u0026deg; elevation angles with the objective of effectively reducing the area of range folding regions (i.e., purple-colored areas) in radial velocity maps. At the 1.8\u0026deg; elevation angle\u0026mdash;largely free from ground clutter interference\u0026mdash;both modes employ the B (batch) alternating scanning scheme (as hereafter). Both VCP12D and VCP212D complete 17 sweeps across 14 elevation angles in approximately 4 minutes. The primary distinction resides in the number of velocity pulses: at the three lowest elevation angles, VCP12D utilizes 40 velocity samples, while VCP212D employs 64 samples. In general, a greater number of samples is associated with improved radar detection quality.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 VCP215D\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThe VCP215D mode, categorized as a general precipitation mode, represents an upgraded version of VCP21D. It incorporates 2 additional low-level, 2 mid-level, and 2 upper-level elevation angles. For the three lowest elevation angles, the CS/SZCD separated sampling scheme is employed, and the mode completes 18 sweeps across 15 elevation angles within 6 minutes and 7 seconds. Compared with the VCP21D mode, VCP215D incorporates 6 additional scanning elevation angles, thereby achieving a marked enhancement in vertical detection resolution. Furthermore, relative to VCP21D, the maximum unambiguous velocity of VCP215D at upper-level elevation angles (10.0\u0026deg;, 12.0\u0026deg;, 14.0\u0026deg;, 16.7\u0026deg;, 19.5\u0026deg;) is increased to 33.36 m/s\u0026mdash;whereas for VCP21D, the maximum unambiguous velocity at elevation angles above 9.9\u0026deg; is 30.73 m/s. At low-level elevation angles (0.5\u0026deg;, 0.9\u0026deg;, 1.3\u0026deg;), VCP215D\u0026rsquo;s maximum unambiguous velocity is raised to 28.47 m/s, in contrast to 26.38 m/s at the lowest elevation angles of VCP21D.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 VCP35D\u003c/h2\u003e \u003cp\u003eThe VCP35D mode is clear-air mode and an upgraded version of the VCP31D mode, incorporates 2 additional lower-level elevation angles and 2 additional mid-level elevation angles. For the three lowest elevation angles, the CS/SZCD separated sampling scheme is employed, and it completes 12 sweeps across 9 elevation angles in 6 minutes and 50 seconds. Compared with the VCP31D mode, the VCP35D mode, on the one hand, reduces the scanning time and enhances detection timeliness; on the other hand, through adjustments to scanning elevation angles, it enables more detailed characterization of structural features across radar layers. Additionally, relative to the VCP31D mode, its maximum unambiguous velocity is increased from 11.6 m/s to 26.38 m/s.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Differences in the Sensitivity of Base Data\u003c/h2\u003e \u003cp\u003eRadar sensitivity refers to the minimum signal detectable by radar when detecting different distances. SYSCAL is a target constant for radar linear channel gain calibration, which can comprehensively reflect the static and dynamic measurement biases of radar in reflectivity factor measurement \u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. In the following, the detection test data of two weather processes with different characteristics\u0026mdash;cold vortex severe convection on September 10\u0026ndash;11, 2021, and blizzard on November 7\u0026ndash;9, 2021\u0026mdash;are used for sensitivity analysis.\u003c/p\u003e \u003cp\u003eThe radar sensitivity of base data from the September 10\u0026ndash;11, 2021 process was analyzed. Base data from 23:01 to 23:22 on September 10 (Beijing Time, hereinafter the same) were selected for sensitivity calculation. During this period, five VCPs, namely VCP11D, VCP12D, VCP21D, VCP212D, and VCP215D, were sequentially used for detection tests (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). The minimum sensitivity values of these five VCPs at 50 km from the radar were \u0026minus;\u0026thinsp;8.0 dBz, -9.0 dBz, -7.5 dBz, -8.5 dBz, and \u0026minus;\u0026thinsp;8.0 dBz, respectively, with little difference among the values. VCP12D exhibited the highest sensitivity, followed by VCP212D, then VCP11D and VCP215D, while VCP21D showed the lowest sensitivity. During this detection period, SYSCAL remained consistently 40.2 dB, and the detection of reflectivity was very stable during the switching of the five detection modes.\u003c/p\u003e \u003cp\u003eThe radar sensitivity of base data from the November 7\u0026ndash;9, 2021 process was analyzed. Base data from 07:35 to 08:28 on November 8 were selected for sensitivity calculation. During this period, four VCPs, namely VCP215D, VCP21D, VCP31D, and VCP35D, were used for detection tests (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). The minimum sensitivity values of these four VCPs at 50 km from the radar were \u0026minus;\u0026thinsp;8.0 dBz, -8.0 dBz, -17.5 dBz, and \u0026minus;\u0026thinsp;8.0 dBz, respectively. VCP215D, VCP21D, and VCP35D exhibited consistent sensitivity, while VCP31D showed the highest sensitivity. The SYSCAL values for VCP215D, VCP21D, and VCP35D were all 39.7 dB, whereas that for VCP31D was 34.9 dB. During this detection period, reflectivity detection remained very stable when switching among VCP215D, VCP21D, and VCP35D. The reason for the differences in sensitivity and SYSCAL between VCP31D and the other patterns lies in the fact that VCP31D uses long pulses (with a pulse width of 4.5 \u0026micro;s), while the other patterns use short pulses (with a pulse width of 1.57 \u0026micro;s).\u003c/p\u003e \u003cp\u003eDifferent color blocks in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e indicate differences in the amount of detected data. By comparing VCP215D and VCP21D in the two processes, VCP215D has more detection elevations, resulting in a significantly greater amount of detected data than VCP21D. More data can more accurately reflect the echo morphology and fine structural characteristics.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Detect Vertical Structural Difference\u003c/h2\u003e \u003cp\u003eDifferences in radar products among different VCPs mainly lie in the differences in vertical detection accuracy caused by the density of detection elevations, and are also related to the number of samples and PRF. The detection effect of radar on storms is directly related to the relative position of the storm with respect to the radar \u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e,\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eTaking the Yingkou weather radar as an example, the radar blind cone has a significant impact near the radar. At 25 km from the radar, the maximum data height achievable in the vertical direction is 9 km (i.e., the detection height at a 19.5\u0026deg; elevation angle, hereinafter the same). For vigorous severe convective storms, the radar can only detect their lower and middle-level structural characteristics. At 50 km from the radar, data at a height of 18 km can be obtained in the vertical direction. At this distance, most of the radar's scanning elevations can pass through convective storms, enabling a relatively complete reflection of their structural characteristics. High elevations can detect the storm tops, while middle and low elevations can well reflect the status of the lower and middle parts of thunderstorms. VCP21D has detection gaps in the upper levels, but the new patterns (VCP12D, VCP212D, and VCP215D) with more detection elevations can accurately depict the storm structural characteristics, which is conducive to detecting mesocyclones, shear, convergence, divergence and other information in radial velocity products.\u003c/p\u003e \u003cp\u003eWith the increase in distance from the radar, the number of effective detection elevations gradually decreases. At 200 km from the radar, the height of middle and high elevations above the ground is much higher than the vertical extension height of thunderstorms. Generally, only elevations below 4\u0026deg; have effective detection at this distance (the 4.3\u0026deg; elevation at 200 km is approximately 17.7 km above the ground). The increased low-level elevations of the new patterns (VCP12D, VCP212D, VCP215D) exhibit their detection advantages. The traditional patterns (VCP11D, VCP21D, VCP31D) only have 2\u0026ndash;3 effective detection elevations at this distance (4\u0026ndash;5 effective detection elevations for extremely vigorous convective cells), while VCP12D, VCP212D, and VCP215D can have 4\u0026ndash;6 effective detection elevations (6\u0026ndash;8 effective detection elevations for extremely vigorous convective cells). Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the schematic diagrams of VCP21D and VCP215D. It can be seen that in vertical detection, the vertical detection performance of VCP215D is superior to that of VCP21D both near and far from the radar.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.3 Differences in Clutter Suppression Capability\u003c/h2\u003e \u003cp\u003eClutter is divided into normal clutter caused by ground objects such as mountains and high towers under the normal propagation of radar beams, and abnormal clutter caused by superrefraction of radar beams under special meteorological conditions. The filtering method used by the Yingkou weather radar is two-dimensional Doppler point clutter filtering, which refers to the two-dimensional (3\u0026times;3 azimuth and range) point clutter filtering applied to Doppler data.\u003c/p\u003e \u003cp\u003eRadar base data reflectivity products include pre-filtered reflectivity (Total Reflectivity, data type: dBT) and post-filtered reflectivity (Reflectivity, data type: dBz). The filtering effect can be represented by comparing the differences between the dBT and dBz products of the corresponding pattern\u0026mdash;specifically, using the difference between the area occupied by each reflectivity level in the dBT product and that in the dBz product at the 0.5\u0026deg; elevation angle. This comparison is then used to further analyze the differences in clutter suppression capability among different VCPs.\u003c/p\u003e \u003cp\u003eClutter exhibits differences under different seasons and meteorological conditions. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the comparison of filtering effects (i.e., the difference between the area of pre-filtered reflectivity and that of post-filtered reflectivity) among various VCPs during three events: September 10, 2021 (a), June 10, 2023 (b), and November 8, 2021 (c). The same VCP exhibits significant differences in filtering results among the three weather events. However, during the same event, there is little difference in filtering effects among different VCPs, with basically consistent variation trends\u0026mdash;indicating that the differences in clutter suppression capability among different VCPs are insignificant.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eVCP11D, VCP12D, and VCP212D are severe convective modes; VCP21D and VCP215D are general precipitation modes; and VCP31D and VCP35D are clear-air modes. In the following, combined with typical cases, we analyze the differences in products among different VCPs, the causes of these differences, and the superiority of the new VCP modes.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e4.1 Case Study of Severe Convection on September 10, 2021\u003c/h2\u003e \u003cp\u003eFrom September 10 to 11, 2021, affected by the Northeast Cold Vortex, severe convective weather occurred in the central and eastern parts of Liaoning Province. The maximum rainfall reached 194.5 mm, and the maximum hourly precipitation was 79.1 mm. Local areas of Benxi, Dandong, Yingkou, and Liaoyang experienced instantaneous gales of magnitude 8\u0026ndash;10, while local areas of Anshan, Dandong, Yingkou, and Liaoyang witnessed large hailstones with a diameter of 3\u0026ndash;5 cm.\u003c/p\u003e \u003cp\u003eStarting at 20:00 on the 10th, convective echoes generated over the northern coastal area of Yingkou and rapidly intensified into multi-cell storms. Some multi-cell storms moved northeastward and further intensified into supercell storms, which successively affected Yingkou, Anshan, and Liaoyang, causing severe wind and hail weather in these three regions. From 23:01 to 23:22, five VCPs\u0026mdash;VCP11D, VCP12D, VCP21D, VCP212D, and VCP215D\u0026mdash;were continuously used for detection tests. The aforementioned supercell storm was selected for the applicability analysis of detection products from different VCPs. Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e shows the radar product detection results of the five VCP scans for this supercell. The first row presents the distribution changes of the supercell at the 0.5\u0026deg; elevation angle, while Rows 2\u0026ndash;5 display the cross-sectional structures along the position indicated by the yellow solid line on the 0.5\u0026deg; horizontal plane.\u003c/p\u003e \u003cp\u003eAt 23:01, VCP11D was used. The main echo was 35\u0026ndash;55 km away from the radar, and thunderstorm echoes were detected by all 14 detection elevations of the pattern. Among them, the vertical extension height of 30 dBz was 11 km (at a 14.0\u0026deg; detection elevation), while the two highest elevations (16.7\u0026deg; and 19.5\u0026deg;) showed weak echoes with an intensity of -5ཞ5 dBz, which is a \"false cusp\" feature caused by side lobe echoes.\u003c/p\u003e \u003cp\u003eAt 23:07, VCP12D was adopted. The main echo was 35\u0026ndash;55 km from the radar, and thunderstorm echoes were captured by all 14 detection elevations of the pattern. The vertical extension height of 30 dBz was 11 km (at a 14.0\u0026deg; detection elevation), and the echo intensity at the two highest elevations (15.6\u0026deg; and 19.5\u0026deg;) ranged from \u0026minus;\u0026thinsp;5 to 10 dBz.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAt 23:11, VCP21D was used. The echo distance from the radar was 35\u0026ndash;65 km, and thunderstorm echoes were detected by all 9 detection elevations of the pattern. Among them, the vertical extension height of 30 dBz was 11 km (at a 9.9\u0026deg; detection elevation), while only a small amount of weak echoes were observed at the two highest elevations (14.6\u0026deg; and 19.5\u0026deg;) with an intensity of -5ཞ5 dBz. On the vertical cross-section, an obvious echo gap can be seen on the side far from the radar. This gap is caused by the inability to perform interpolation due to the presence of detection gaps between the radar beams at upper elevations, leading to the incomplete presentation of the echo's vertical structure. Meanwhile, due to the small number of elevations in this VCP, a dome-like structural characteristic appeared at 5\u0026ndash;10 km during the vertical cross-section interpolation. By comparing with the four adjacent scans (the two before and two after), it can be judged that this structural characteristic has deviations.\u003c/p\u003e \u003cp\u003eAt 23:17, VCP212D was used. The echo was 40\u0026ndash;75 km away from the radar, and thunderstorm echoes were detected by all 14 detection elevations of the pattern. Among them, the vertical extension height of 30 dBz was 12 km (at a 10.0\u0026deg; detection elevation), and the echo intensity at the three highest elevations (12.5\u0026deg;, 15.6\u0026deg;, and 19.5\u0026deg;) ranged from \u0026minus;\u0026thinsp;5 to 20 dBz. Compared with VCP21D at the previous time, although the storm cell was farther from the radar at this time, the addition of a 12.5\u0026deg; detection elevation improved the continuity of vertical detection, thus capturing a more complete vertical structure of the storm.\u003c/p\u003e \u003cp\u003eAt 23:22, VCP215D was adopted. The echo was 45\u0026ndash;77 km away from the radar, and thunderstorm echoes were detected by all 15 detection elevations of the pattern except the topmost one (19.5\u0026deg;). The vertical extension height of 30 dBz was 12 km (at a 10.0\u0026deg; detection elevation), and the echo intensity at the second-highest two elevations (14.0\u0026deg; and 16.7\u0026deg;) was \u0026minus;\u0026thinsp;5ཞ5 dBz. The vertical structure of the storm detected by the radar at this time was still relatively complete.\u003c/p\u003e \u003cp\u003eComparing the vertical cross-sections of the average radial velocity (V), differential reflectivity (ZDR), correlation coefficient (CC), and specific differential phase (KDP) products among the five VCPs, similarly, VCPs with more scanning elevations exhibit better product continuity. In particular, VCP212D, VCP12D, and VCP215D have more low-level elevations, presenting more detailed low-level echo structures.\u003c/p\u003e \u003cp\u003eLikewise, more scanning elevations can better reflect the storm top height, which is one of the characteristic indicators of the development intensity of thunderstorm cells. Echo Top Height (TOPS) plots refer to the height of the highest elevation where the reflectivity factor is \u0026ge;\u0026thinsp;18 dBz. It can be seen from the TOPS plots of the five time periods in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e that due to the fewer scanning elevations, VCP21D shows an obvious \"stepped\" echo morphology, and the detected echo top height is significantly discontinuous and lower than that of the other four VCPs, while VCP215D achieves the best detection performance.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e4.2 Case Analysis of a Heavy Snowstorm Event on November 8, 2021\u003c/h2\u003e \u003cp\u003eFrom November 7 to 9, 2021, affected by the Northeast Cold Vortex and the strong development of the surface cyclone, Liaoning Province experienced a rare combination of extreme heavy snowstorm, snow-rain freezing, cold wave, and gale weather in history. The average precipitation at 62 national meteorological observation stations across the province was 41.1 mm, with 39 stations recording extreme heavy snowstorm. The snow-rain process was accompanied by instantaneous gales of magnitude 11, a sharp temperature drop of more than 16 ℃, freezing, and weak thunder and lightning. Four VCPs\u0026mdash;VCP215D, VCP21D, VCP31D, and VCP35D\u0026mdash;were used for detection tests during this event. The following is an analysis of the radar products from VCP215D at 07:35, VCP35D at 07:50, VCP21D at 08:05, and VCP31D at 08:17 on the 8th.\u003c/p\u003e \u003cp\u003eDuring this period, the system developed stably with little change in echo morphology, exhibiting strong comparability. Among the four VCPs, VCP215D, VCP21D, and VCP35D utilize short pulses, while VCP31D employs long pulses. Figure\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e presents a comparison chart of the reflectivity factor area by intensity level at the 0.5\u0026deg; elevation angle for the four VCPs. By counting the detected data with intensity greater than \u0026minus;\u0026thinsp;5 dBz, it can be observed from the figure that the data distribution trends of VCP215D, VCP21D, and VCP35D are basically consistent. VCP31D detects significantly more data in the weak echo region (-5ཞ5 dBz), which is attributed to the longer dwell time of its pulse beam and the larger volume of sampled data. Meanwhile, the amount of strong echo data (\u0026ge;\u0026thinsp;65 dBz) detected by VCP31D is also higher than that of the other VCPs, and clutter is more prominent in VCP31D's products.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eBy comparing the reflectivity charts at 0.5\u0026deg; elevation (the upper part of Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e), it can also be observed that the echo area of VCP31D is significantly larger than that of other VCPs, enabling it to better depict the outline of the cloud system. On the vertical cross-sections of reflectivity (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e), VCP31D has a maximum elevation angle of 4.5\u0026deg; and the largest scope of the echo blind cone area; followed by VCP35D with a maximum elevation angle of 6.4\u0026deg;; both VCP215D and VCP21D have a maximum elevation angle of 19.5\u0026deg; and the smallest blind cone area. Regarding echo continuity, VCP215D achieves the best performance.\u003c/p\u003e \u003cp\u003eOn the average radial velocity charts, different VCPs use different PRF at various elevations, resulting in distinct maximum unambiguous velocities. Taking the 0.5\u0026deg; elevation as an example: for VCP21D and VCP35D, the maximum unambiguous velocity is 26.38 m/s with an effective detection range of 148 km; VCP215D has a maximum unambiguous velocity of 28.47 m/s and an effective detection range of 137 km; for VCP31D, the PRF is 322 s⁻\u0026sup1;, and its detectable maximum unambiguous velocity is only 8.38 m/s, while the effective detection range reaches 466 km. It can be observed from the radial velocity chart at 0.5\u0026deg; elevation (the lower part of Fig.\u0026nbsp;7) that the average radial velocity range of VCP31D is significantly larger than that of other VCPs. However, it also exhibits obvious velocity aliasing\u0026mdash;even second-order aliasing.\u003c/p\u003e \u003cp\u003eVCP35D is an upgraded version of VCP31D. When compared with VCP31D, VCP35D has a slightly smaller detected data range and slightly weaker weak echo detection capability. However, it features a shorter scanning time (3 minutes less than VCP31D), more scanning elevations, and a larger maximum unambiguous velocity, exhibiting obvious advantages in clear-air echo detection.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eTo address the issues of insufficient vertical sampling below 5\u0026deg; elevation and existing detection gaps in the vicinity for the VCP21D volume coverage pattern, drawing on the volume scan modes of the WSR-88D radar, has developed four new volume coverage patterns (VCP12D, VCP212D, VCP215D, and VCP35D) that differ from the current operational modes. Operational tests were conducted using the Yingkou dual-polarization weather radar, and comparative analyses of the test products were performed. The conclusions are as follows:\u003c/p\u003e \u003cp\u003e(1) At 50 km, the minimum sensitivity, data quality, and clutter suppression capability of the four new VCPs are basically consistent with those of VCP21D. They meet the operational performance indicators and can be applied in operational practice.\u003c/p\u003e \u003cp\u003e(2) Compared with VCP11D, VCP12D and VCP212D have improved low-level vertical resolution, enabling them to obtain more detailed detection data beyond 100 km from the radar. Meanwhile, the scanning time is shortened from 5 minutes to 4 minutes, resulting in better detection performance for rapidly developing severe convective storms. With short detection cycles and more elevations, VCP12D and VCP212D are suitable for application in severe convective weather processes.\u003c/p\u003e \u003cp\u003e(3) Compared with VCP21D, VCP215D has an additional 6 detection elevations, which allows for more continuous vertical detection products. It can display more complete and detailed echo structural characteristics on cross-sections and calculate the storm top height more accurately. Additionally, its detection time is comparable to that of VCP21D, demonstrating obvious advantages. VCP215D can replace VCP21D in the detection of severe convective weather and large-scale snow-rain weather processes.\u003c/p\u003e \u003cp\u003e(4) Although VCP35D has a slightly smaller detected data range than VCP31D, it features shorter scanning time, more detection elevations, and higher spatiotemporal resolution of products, showing significant detection advantages.\u003c/p\u003e \u003cp\u003e(5) Compared with the original modes, all four new VCPs (VCP12D, VCP212D, VCP215D, and VCP35D) have improved maximum unambiguous velocity. Specifically, the maximum unambiguous velocity of VCP12D, VCP212D, and VCP215D can reach 33.36 m/s at upper levels (above 10\u0026deg;); VCP212D and VCP215D have an improved maximum unambiguous velocity of 28.47 m/s at low levels (0.5\u0026deg;\u0026ndash;1.3\u0026deg;); and VCP35D has an overall improved maximum unambiguous velocity of 26.38 m/s throughout the entire layer.\u003c/p\u003e \u003cp\u003eIt should be noted that to ensure the quality of normal operational detection and enhance the comparability of different products, the operational experiment of the new VCPs adopted a method of continuously switching between the new and original VCPs. Specifically, during a certain period of a single weather process, continuous switching of volume scan modes was performed to obtain relatively continuous comparative data.\u003c/p\u003e \u003cp\u003eFor a more comprehensive evaluation of the new VCPs, continuous and complete detection of a single weather process using the same new VCP should be conducted. Meanwhile, further research should be carried out on the matching between the new VCPs and the existing radar algorithms.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u003c/strong\u003e All authors have contributed to this article. Lin Ma is responsible for conceptualizing experimental ideas and analyzing data, Diya Zhang is responsible for writing and revising articles, Shi Zheng is responsible for revising articles, Jing Zhang is responsible for designing experimental plans, and Wen Yao is responsible for implementing experiments and analyzing results. Jiusong Yuan and Dong Wang are responsible for analyzing results.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e This research received no external funding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement:\u003c/strong\u003e Due to privacy protection of meteorological data, the research data involved in this article should not be disclosed. If you are interested in this research, please contact [email protected].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u003c/strong\u003e The authors would like to express their gratitude to Liaoning Meteorological Equipment Support Center and Yingkou Meteorological Service for technical support. We also appreciate the valuable feedback from all reviewers during the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003cstrong\u003e:\u003c/strong\u003e The author declares that there are no conflicts of interest regarding the publication of this article. All research activities were conducted without any influence from personal or external interests that could bias the results.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eMaddox, R.\u003cem\u003e\u0026nbsp;et al.\u003c/em\u003e Echo height measurements with the WSR-88D: Use of data from one versus two radars. \u003cem\u003eWeather forecasting\u003c/em\u003e \u003cstrong\u003e14\u003c/strong\u003e, 455-460, doi:https://doi.org/10.1175/1520-0434(1999)014,0455:EHMWTW.2.0.CO;2 (1999).\u003c/li\u003e\n \u003cli\u003eWitt, A. in \u003cem\u003ePreprints, 28th Conf. on Radar Meteorology, Austin, TX, Amer. Meteor. 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Comparison of CINRAD/SA Volume Coverage Patterns on Algorithms Output. \u003cem\u003eMeteorological Monthly\u003c/em\u003e \u003cstrong\u003e32\u003c/strong\u003e, 44-50 (2006).\u003c/li\u003e\n \u003cli\u003ePeiyuan, Z., Hongping, Y. \u0026amp; shaoping, H. Applications of New Generation Weather Radar to Nowcasting and Warning of Severe Weather. \u003cem\u003eMeteorological Monthly\u003c/em\u003e \u003cstrong\u003e34\u003c/strong\u003e, 3-11 (2008).\u003c/li\u003e\n \u003cli\u003eJianfeng, Q., Xiaoyu, X., Ming, T., Shengchao, C. \u0026amp; Hong, C. SYSCAL Based On line Calibration Technique of Weather Radar Reflectivity Factor. \u003cem\u003eMeteorological Science and Technology\u003c/em\u003e \u003cstrong\u003e45\u003c/strong\u003e, 962-967 (2017).\u003c/li\u003e\n \u003cli\u003eDianli, G., Junjian, Z., Qufeng, L. \u0026amp; Jian, G. Radar Observation Analysis of Severe Hailstorm and Tornado Caused by a Supercell in Autumn. \u003cem\u003eMeteorological Monthly\u003c/em\u003e \u003cstrong\u003e50\u003c/strong\u003e, 561-576, doi:10.7519/j.issn.1000-0526.2023.110101 (2024).\u003c/li\u003e\n \u003cli\u003eWen, Y.\u003cem\u003e\u0026nbsp;et al.\u003c/em\u003e Dual-Polarization Weather Radar Echo Characteristics of Avian Activities in the Liaohe River Delta Wetland. \u003cem\u003eMeteorological Monthly\u003c/em\u003e \u003cstrong\u003e48\u003c/strong\u003e, 1162-1170, doi:10.7519/j.issn.1000-0526.2022.041401 (2022).\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"dual-polarization, weather radar, Volume Coverage Pattern (VCP), sensitivity, vertical detection","lastPublishedDoi":"10.21203/rs.3.rs-9275613/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9275613/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAiming at the problem that China's current Volume Coverage Pattern (VCP) of VCP21D has insufficient vertical sampling below 5\u0026deg; elevation angle, and there is a detection gap nearby, four new VCPs (VCP12D, VCP212D, VCP215D, and VCP35D) were developed based on the WSR-88D VCP framework. Testing was conducted using the Yingkou dual-polarization weather radar. The results indicate that: (1) The four new VCPs exhibit basically consistent detection sensitivity, data quality, and ground clutter suppression capability with the existing VCP21D, suitable for business application. (2) Compared with VCP11D, the severe convective detection modes (VCP12D and VCP212D) enhance lower-level vertical resolution, the scanning time is reduced from 5 minutes to 4 minutes, thereby improving detection performance for rapidly evolving severe convective storms. (3) Relative to VCP21D, the non-severe convective precipitation mode (VCP215D) increases the number of detection elevation angles by 6 layers. This allows for a more comprehensive and detailed characterization of echo structural features and storm top height. (4) In comparison with VCP31D, the clear-air mode (VCP35D) has a slightly smaller detection range but higher spatiotemporal resolution, presenting significant superiority in clear-air detection. (5) The new VCPs have increased the maximum unambiguous velocity.\u003c/p\u003e","manuscriptTitle":"Applicability analysis of Dual-Polarization Weather Radar's Four Volume Coverage Patterns","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-13 09:32:15","doi":"10.21203/rs.3.rs-9275613/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-27T07:07:00+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-24T15:10:23+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-13T07:08:48+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"292927275145761375263325938166846379136","date":"2026-04-10T03:13:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"86097613007123582415016336037361160580","date":"2026-04-08T03:11:48+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-07T01:48:21+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-06T12:46:42+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-01T05:00:19+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-01T04:59:20+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-03-31T06:38:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"64c5d0f7-22b0-41a0-9da7-34901f4d9d50","owner":[],"postedDate":"April 13th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[{"id":66051876,"name":"Earth and environmental sciences/Climate sciences"},{"id":66051877,"name":"Earth and environmental sciences/Natural hazards"}],"tags":[],"updatedAt":"2026-04-30T08:59:37+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-13 09:32:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9275613","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9275613","identity":"rs-9275613","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}