Flying Laboratory of Imaging Systems: Fusion of Airborne Hyperspectral and Laser Scanning for Ecosystem Research

Round 1

Reviewer 1 Report

This manuscript describes, in a clear and detailed manner, Czech Globe’s Flying Laboratory of Imaging Systems (FLIS) - its platform and sensors, the procedures used in designing data acquisition plans and the pre-processing steps used to generate products. It identifies the unique value of FLIS vis-à-vis other remote sensing platforms, namely RPASs and satellites.

My comments are mostly editorial in nature, with some minor grammatical corrections suggested.

(line number: comment)

l.30: the sentence “provides … framework for the assessment of …. but also to study…” could be improved with: “provides … framework for the assessment of …. as well as for studying …”

l.348-359, Figures 2 and 3: the description of the vegetation anisotropic reflectance simulation belongs somewhere other than the flight planning section, perhaps in its own section.

l.375: the sentence “Sites with seamless mosaics without the need for additional BRDF corrections can be used for instance as calibration surfaces for satellite data or for analysis in time.” Would be better written as “Sites with seamless mosaics, generated without the need for additional BRDF corrections, can be used, for instance, as calibration surfaces for satellite data or for analysis in time.”

L.486, Figures 7 and 8: Description of the CSF method belongs elsewhere than section 4.2.2 Georeferencing

l.551: the words “dual black body method” appears to be extraneous text at the end of the sentence

l.553: the sentence “The accuracy of spectral shift determined by the heated black body significantly improved compared to the ambient black body data.” Needs revision. I suggest “The accuracy of spectral shifts determined by the heated black body is significantly improved compared to corrections that use the ambient black body data alone.”

l.578: “spatially and timely” -> “spatially and temporally”

l.623: Figure 9c lacks a color scale

only a few very minor grammatical corrections are needed

Author Response

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Reviewer 2 Report

Hanuš et al presented an airborne platform that’s capable of acquiring broad spectral (three spectroradiometers) as well as topography (LiDAR) scan data. This synchronous multi-source acquisition system is versatile and ideal for prompt assessment of local ecosystems. In addition, the authors explained the complexity in flight path design and data processing. Here are some comments for the manuscript:

My main suggestion for this project (not necessarily for the manuscript) is to have more focus on the usage and user – this platform could be useful for all sorts of reginal ecosystem studies. In my opinion, it’s more useful for make it reliable and assessable for potential users than increasing its technical capabilities.

The modeling part can benefit from better illustration and explanation. A few points I found confusing at the moment:

1/ The virtual 3D spruce forest scene should be shown. The exact setup is unclear based on current description. Are the trees uniformly distributed ? If so, why are plots in figure 2 not symmetric along the 150 degree azimuth?

2/ I found figure 2 somewhat confusing. This is the reflectance plot viewed from a hyperspectral sensor, correct? If so, the sun position should not be plotted on this reference frame. Explicit definitions of the coordinate system should be helpful here. It’s said the sun is at 45 degree zenith but then the center of these plots is of 0 degree zenith – aren’t the center corresponding to the position right below the sensor on the ground ?

3/ line 361, if the flight line is perpendicular to the solar principal plane, then the flight line azimuth should be 90 degrees away from the sun’s azimuth, no ? (see figure 3)

4/ I can see a forest setup is simpler for simulation. But the authors have argued in the introduction that the advantage of the FLIS is surveying urban environment. Why not simulate some urban settings ?

For data processing and calibration, it’s hard for me to comment on the detailed methods and procedures. What would be helpful is to have comparison with some sort of ground truth references. For example, after calibration, what are the expected uncertainties for a given module during normal operation conditions?

Figure 6, I found this kind of figures least informative.

good

Author Response

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Reviewer 3 Report

The manuscript entitled remotesensing-2443517” dealing with the laser has been reviewed. The paper has been nicely written but needs some improvement. Please follow my comments.

1.     Remove hyperlink in the introduction and replace them with the normal references. You can add hyperlink to endnote and then add them to the text.

2.     What is the industrial application of ultrashort laser pulses?

3.     Please proofread the paper.

4.     What you are trying to deliver by figure 1? It is not scientific.

5.     Conclusion is too short and is not following the main part of the paper.

6.      What is the future direction of this work? Please add it in the segmented section.

7.      Laser has many application in industries such as laser in additive manufacturing.. Refer to the following paper to highlight this note in your manuscript. “Additive manufacturing a powerful tool for the aerospace industry”. “Assessing the influence of non-uniform gas speed on the melt pool depth in laser powder bed fusion additive manufacturing”.

Needs proofread. 

Author Response

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