Estimating beam pointing of vertically pointing cloud radars using radiosonde measurements

Deng, Min; Giangrande, Scott E.; Theisen, Adam K.; Johnson, Karen L.; Lindenmaier, Iosif A.; Wendler, Timothy G.; Comstock, Jennifer; Rocque, Marquette; Zhu, Zeen; Matthews, Alyssa

doi:10.5194/amt-19-6327-2026

Articles | Volume 19, issue 19

https://doi.org/10.5194/amt-19-6327-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/amt-19-6327-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 19, issue 19

Research article

|

06 Oct 2026

Research article |

| 06 Oct 2026

Estimating beam pointing of vertically pointing cloud radars using radiosonde measurements

Min Deng, Scott E. Giangrande, Adam K. Theisen, Karen L. Johnson, Iosif A. Lindenmaier, Timothy G. Wendler, Jennifer Comstock, Marquette Rocque, Zeen Zhu, and Alyssa Matthews

Download

Final revised paper (published on 06 Oct 2026)
Preprint (discussion started on 12 Jun 2026)

Interactive discussion

Status: closed

RC1:
'Comment on egusphere-2026-3304', Anonymous Referee #1, 15 Jul 2026

This is an interesting study that uses radiosonde wind measurements to estimate how well a “vertically pointing beam” is actually pointed vertically. This manuscript is well written and should be published in the Journal of Atmospheric Measurement Techniques.

Citation: https://doi.org/10.5194/egusphere-2026-3304-RC1
- AC1: 'Reply on RC1', Min Deng, 14 Aug 2026
  
  We sincerely thank the reviewer for the positive assessment of our study and for recommending its publication in Atmospheric Measurement Techniques. We wish this U wind Normalized Velocity Direction Display (UN-VDD) techinique would be helpful for all vertically pointing radars observations.
  
  Citation: https://doi.org/10.5194/egusphere-2026-3304-AC1
RC2:
'Comment on egusphere-2026-3304', Anonymous Referee #2, 16 Jul 2026

The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2026/egusphere-2026-3304/egusphere-2026-3304-RC2-supplement.pdf

Citation: https://doi.org/10.5194/egusphere-2026-3304-RC2
- AC2: 'Reply on RC2', Min Deng, 14 Aug 2026
  
  Thank you for your careful and detailed review of our manuscript. We have addressed your comments concerning the literature review, methodological description, uncertainty analysis, and practical application of the proposed method. Changes in the revised manuscript are shown in blue.
  We also added a new Fig. 4 to illustrate the U-normalized velocity–direction display (UN-VDD) beam-pointing retrieval. In addition, we expanded the Discussion and Conclusions to address operational monitoring and correction of Doppler-velocity contamination caused by off-vertical pointing. More details can be found in the attached file.
  
  Citation: https://doi.org/10.5194/egusphere-2026-3304-AC2

Peer review completion

AR – Author's response | RR – Referee report | ED – Editor decision | EF – Editorial file upload

AR by Min Deng on behalf of the Authors (14 Aug 2026) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (18 Aug 2026) by Haoran Li

RR by Anonymous Referee #2 (28 Aug 2026)

Suggestions for revision or reasons for rejection

The manuscript has improved considerably in the revised version. The methodology is now clearer and more reproducible, and the added discussion helps to put the results into better context. The main comments from the previous review have been addressed, and the major concerns are resolved. Only a few minor comments remain, mainly related to clarification and presentation. Overall, the manuscript is in good shape and suitable for publication after these points are addressed.

- Line 74: “several radars deployed” instead of “several radar deployed ...”
- lines 90-97: This paragraph interrupts the storyline at the beginning of the introduction. Consider moving it towards the end of the introduction, where the instruments used in the study are introduced.
- lines 115-118: Consider rewriting this part to make the content clearer for the reader. Instead of using one long sentence, it may be easier to follow if the information is divided into several shorter sentences.
- line 132: “quantitatively retrieving both pointing angles” Please clarify which two angles “both” refers to, as they have not been introduced earlier in the text.
- line 164: “the cloud radar signal processor” instead of “the cloud radar signal processo”
- line 225: “off vertical tilt angle is defined as” instead of “off vertical tilt angle. Is defined as”
- Fig. 3: “and radar zenith pointing angles (θ0)” Typo: “zenith” should be elevation. Please check the manuscript for similar inconsistencies and correct them where necessary.
- lines 311-312: Please clarify that the 150-minute time window is taken both before and after the radiosonde launch, as shown in Figure 1. In the current description, it could be interpreted as a 150-minute window centered on the radiosonde launch (i.e., 75 minutes before and 75 minutes after). It may also be helpful to state explicitly that this results in a total averaging period of 300 minutes.
- lines 316-317: Please clarify the approximate vertical spacing of the radiosonde data grid. This would help the reader understand how many radar gates are contained within one radiosonde grid cell.
- lines 346-347: The revised text provided in the response to the reviewer does not appear to have been incorporated into the manuscript. Please update this section accordingly.
- lines 358 and 374: “an elevation pointing angle θ0 of approximately 87.5◦” instead of “a zenith pointing angle θ0 of approximately 87.5◦”
- line 456: The sensitivity to the reflectivity threshold is evaluated later in the manuscript, but the threshold itself is not introduced beforehand. Please state in the Methods section which reflectivity threshold is used for the main analysis.

Hide

RR by Anonymous Referee #1 (28 Aug 2026)

ED: Publish subject to minor revisions (review by editor) (01 Sep 2026) by Haoran Li

AR by Min Deng on behalf of the Authors (01 Sep 2026) Author's response Author's tracked changes Manuscript

ED: Publish as is (11 Sep 2026) by Haoran Li

AR by Min Deng on behalf of the Authors (18 Sep 2026) Author's response Manuscript

Short summary

Cloud radars are used to measure air motion, clouds, and precipitation, but small pointing errors can reduce their accuracy. We developed a method to detect these errors using routine weather balloon observations. Tests with several radar systems in different environments showed that the method can identify small but important pointing biases, helping improve the accuracy and long-term consistency of weather and climate observations.