On-Orbit Calibration for Spaceborne Line Array Camera and LiDAR

Round 1

Reviewer 1 Report

This paper proposes an on-orbit calibration method for the relative installation of the camera and the LiDAR independent of the calibration field and additional satellite. Overall, the paper is well organized and the English is understandable even if improvable in some passages. The proposed method is extensively discussed in great detail. The simulation of the calibration method is also discussed properly and precisely. For a non-expert scientist in this field like me is difficult to understand what is the real novelty and improvement of this method. In my opinion (even if I'm not sure is doable), in the conclusion, the authors should compare the horizontal positioning means error which in this work is less than 0.8 meters with other methods which are currently employed. This would allow better a clear and immediate feeling about the improvement of the new method.

Author Response

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Reviewer 2 Report

Punctuation in the formulas is absent.
Experimental results need better argumentation and reinforcement.
You need to better explain the difference between Figure 14 and Figure 15, and the connection existende with a LiDAR, which measures distances.

You also need to include reflectivity functions (in this case of distance) that make the results better interpreted.

You need to better explain the origin of the experimental data, why you chose this type of data, etc..

Section of experimental results is too disconnected with secrion discussion.

Then the discussion section simply begins with a numbered list. seems too schematic to me. try to include an introductory preamble.

Also think about comparing your method with a competitor.

Author Response

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Reviewer 3 Report

In this research article, the authors proposed a method for calibrating the line camera and LiDAR simultaneously. The authors evaluated the different errors associated with the calibration process. The authors conducted several simulation experiments to verify the efficiency of the proposed calibration method. However, the authors need to address the following queries:

1.    In Section 2.4.2, the authors had set the rotation matrix (corresponding to the camera calibration) to the identity matrix. Did the authors shift the coordinate system to the other sensor? The authors should explain this in detail.

2.    The authors considered several errors that can affect the calibration accuracy. The authors should explain how the bounds of the errors were decided.

3.    In Section 3, the authors mentioned that the calibration accuracy was evaluated by computing the ground distance of the points estimated by this method and by using the points on the two images. The authors can instead evaluate the accuracy with an existing calibration method to better understand the advantage of this calibration technique.

4.    There are many typographical errors. The authors should proofread the entire article.

Author Response

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Round 2

Reviewer 2 Report

Accepted

Reviewer 3 Report

The authors have addressed all the queries. The article can be accepted for publication.