A High-Precision Method for Evaluating Sector Capacity in Bad Weather Based on an Improved WITI Model

Round 1

Reviewer 1 Report

In the manuscript by Dr. Huang and co-workers the authors develop a modified weather-impacted traffic index (WITI) to improve air traffic sector (ATC) workloads in adverse conditions. The model advances WITI, which was limited to convection, to non-thunderstorm weather. This is important as adverse weather puts increased workload on ATC due to diversions, delays and so forth. Overall, the paper is extremely comprehensive and the authors, presumably non-native English speakers, should be congratulated on their excellent command of the language. I have only some minor criticisms that the authors should address in their Discussion section.

MINOR COMMENTS.

1) The model was developed using data (weather, ATC communications) from the Yinchuan Hedong International airport accrued in 2019. Subsequently, the model was compared with the original WITI and indeed shows superiority (Figure 4.3). However, it would have been nice to see the model validated by using data from a separate airport. The authors should mention this as future work.

2) In Figures 4.1 and 4.2. it would appear that most of the low cloud base heights and reduced visibility are related to higher radar echo intensity i.e. few data points to the extreme left/bottom of each graph.  This would suggest to this reviewer that most of the adverse weather is convective-related (i.e. thunderstorms) but the original objective of the study was to modify WITI to include non-convective weather. Again, this reinforces point #1 where it would have been nice to validate the model using data from another airport.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

An architecture diagram of the overall system would help to understand the working clearly.  Figure 4.6. show the analysis the label of the x-axis and y-axis are missing here. 

Statistical analysis of the parameter would help to understand the significance of variables and the correlation between them. 

The comparative analysis with state-of-the-art machine learning methods is recommended. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

This paper explored three holding area concepts that can control air traffic flows and avoid bad weather conditions when UAM vehicles are operating. This is  a valuable attempt to design corridors and avoid collisions with other UAM vehicles or structures such as buildings. The method is well described and the results are well explained.  I recommend publication after addressing the following points:

- In the introduction, the authors should a paragraph detailing the current research on urban airspace design and more literature references to other design approaches such us the NASA, Mitre approaches.

- Why the FAA route design is adopted here? A paragraph should be added to  justify this choice.

- In equations 1 to , variables khi and g are not defined.

- Figure 12: Why the names have different colors (red, pink and cyan)? What does the blue dot represent? Please add more details in the caption?

- Section 4.3: How the distance between holding areas and vertiports should be defined? Is their a logic behind the positions of the holding areas in Figure 13? What does the circles refer to in Figure 13? A direction to the North should be added. and a map of the position of the city in the world should be added.

- In the conclusion, please clarify where and what are the method and requirements that urban airspace designers should respect when designing urban routes or holding areas in another city.

- Is a vertical profile of the proposed route suggested?

- Other factors such as public acceptance,  are not mentioned, Are they taken into account is the urban airspace design?

- How this study can be generalized  in terms of routes design and holding areas dimensions for a fleet of different UAVs of different performance.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf