The article is helpful. This manuscript makes flux footprint easy to be understood. 

The algorithms make programming easier for applications of Kljun et all 2015) to footprint characteristics while saving computation time.

This preprint does a fantastic job solving the computational hurdles of EC flux footprint analysis with Kljun et al. (2015)’s nondimensional equations. It's helpful for scientists who are interested in EC flux methods.

Enables real-time computation of flux footprint characteristics in field EC systems, compatible with major flux networks—super practical!

By advancing footprint analysis from a post-processing technique to an onboard, operational routine through an embedded algorithm that calculates real-time fetch metrics on low-power dataloggers, this work demonstrates considerable innovation and immediate practical utility.

This is a very detailed study on the application of the footprint model. It would be very useful to users of the Campbell Eddy Covariance Systems. One particular point that is important in my opinion is that the limitations of the Kljun et al. (2015) model should be explicitly discussed. Further clarifications at some places may also be important. The specific comments are provided below.

Line 17 and some lines later. A footprint is a transfer function relating the source area to the measured flux. The footprint itself is not an area. However, the footprint can be used to calculate the footprint. See Steinfeld et al. (2008) and Fu et al. (2025). In addition, even over a horizontally homogeneous terrain, it is likely that the footprint can extend to the downwind side of the EC system. Over complex terrain, as found by Fu et al. (2025), the extension in the downwind direction may be substantial.

References:

Steinfeld, G., Raasch, S., & Markkanen, T. (2008). Footprints in homogeneously and heterogeneously driven boundary layers derived from a Lagrangian Stochastic Particle Model embedded into large‐eddy simulation. Boundary‐Layer Meteorology, 129(2), 225–248. https://doi.org/10.1007/s10546‐008‐9317‐7

Fu, S., Chen, J. M., Zhang, J., Cheng, Z., Miao, G., Wang, R., et al. (2025). Flux footprints over a forested hill derived from a Lagrangian particle model coupled into a large‐eddy simulation model. Journal of Geophysical Research: Atmospheres, 130, e2025JD043591. https://doi.org/10.1029/2025JD043591

Lines 25-29. It is unclear why the model can be efficiently calculated in the field. From the summary section, it becomes clear that some parts are precalculated so it is not necessary to calculate them in the field. I suggest adding this explicitly into the abstract.

Lines 30-31. Since the footprint model by Kljun et al. (2015) was developed for flat ground, it may not be appropriate to state that the model developed based on Kljun et al. (2015) can be used over complex terrain.

Lines 63-75. The discussion of the symmetry seems to suggest that the source area for a negative flux is in the downwind side of the EC system. This is in contrast to my expectation.

Section 4.4. Since the boundary layer height appears at multiple places in the footprint model. It might be important to the users how sensitive the footprint model is to the boundary layer height. In addition, it might be informative to the users if some examples of the boundary layer height are calculated and provided using methods in Appendix B, and these example heights can be compared to the typical values from the literatures.