A Time-Gated, Time-Correlated Single-Photon-Counting Lidar to Observe Atmospheric Clouds at Submeter Resolution
, Yong Meng Sua 2, Alexandros Louridas 3, Katia Lamer 1, Zeen Zhu 1, Edward Luke 1, Yu-Ping Huang 2, Pavlos Kollias 1,4, Andrew M. Vogelmann 1 and Allison McComiskey 1
Round 1
Reviewer 1 Report
This manuscript describes a lidar prototype that is designed and built to provide cloud observations at submeter resolution with a time-gated mode that allows the lidar to focus on a 12-m layer at a time. The illustration of the capability of the lidar prototype indicates promising future for fine-scale remote sensing of detailed cloud structure that will help advance our understanding of cloud microphysical processes. The manuscript is well written and easy to follow. I recommend publication.
Here are some minor comments to consider:
1. The advantages of the T2 lidar is well said and demonstrated, I wonder what will be the limitations of this lidar?
2. Is there plan to make this prototype air-borne capable, e.g., horizontally and/or downward pointing?
3. Line 147, remove ‘to’
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript, entitled with "A Time-Gated Time-Correlated Single Photon Counting Lidar to Observe Atmospheric Clouds at Submeter Resolution" by Yang., et al, introduced a Time Gated Time-Correlated (referred as "T2") lidar for high spatial resolved cloud observations. Basic concept of this lidar was inherited from Barton-Grimley et al, but was extended with a time-gated observation mode to focus on a extremely narrow region of the atmosphere. The design of the prototype lidar system was presented in an detailed way. The manuscript is well-written and very easy to follow. It merits publication after addressing some minor issues.
1. Numbers in Figure 1 (b-c) should be enlarged.
2. I would suggest to add a panel of raw signal profiles in Figure 5, and extend the y-axis to 3 km if available. Because raw signal can be helpful for lidar experts to know more about this lidar, for instance, the background noise and dead-time effects.
3. Line 209, "lidar constant" should be described.
4. Line 211, "..., which is a reasonable value for the atmospheric boundary layer [29]", what do you mean by using "reasonable"? Did you check this value with other measurements, for instance, collocated micropulse lidar, or sunphotometer measurements at daytime? According to the extinction coefficient (~ 0.4 km-1), the AOD could be more than 0.6 (@ 532 nm). I don't think this is a typical value for Brookhaven (please see: https://aeronet.gsfc.nasa.gov/cgi-bin/data_display_aod_v3). In addition, why did you use reference 29? It's not even lidar measurements in US. Better to replace it or remove it.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
