Research of the Photo-Optical Method Application for Measuring Selected Data on the Movement of a Parachute for Type M-282

Round 1

Reviewer 1 Report

The manuscript is very well done, in accordance with the standards of the publisher and the focus of the special issue of the magazine. The topic of the article, whose experimentally verified results have the potential to strengthen the quality and safety of jumps with the M-282 type parachute, demonstrate the potential for further scientific work and verification of the photo-optical method for other types of parachutes and cameras.

Based on the results of parachute test jumps according to the regulation of SAE AS 8015B “Minimum Performance Standard Parachute Assemblies and Components”, the research for the M-282 parachute was completed. For this reason, I recommend that authors make minor corrections to the text:

The main aim of the paper is formulated in lines 121-128. The aim  was clearly defined. The results of the experiment verified the answer to the research question and confirmed the suitability of the photo-optical method for the M-282 parachute type.

In lines 13-19 of the abstract, therefore I recommend the correction of the text: The paper's main aim is to present the results of research for the verification of the photo-optical method of measuring the vertical speed of the M-282 parachutes and for its usability in testing, collecting, and investigating motion data in parachuting. The text is without the wording "preliminary". It was verified that the experiment was completed for the M-282 parachute according to the regulation of SAE AS 8015B "Minimum Performance Standard Parachute Assemblies and Components".

I recommend the manuscript for publication after a minor revision of the text in the abstract and its harmonization with the text that the authors presented in the paper.

Minor recommendations / revisions:

line/lines                    comment

246, 248                     place the figure and the figure name on one side

In the whole article    Discrepancies between figures, tables and equations     compared to the text part when using a subscript for example: in Figure 327, Equation 333 is given k_hor but in Text 337, 338 is given khor

341                              in the description to Table 1, emphasize that the stated c_hor values are intended for k_hor ranges / intervals

356                              same as for line 341

415                              move the equation to the center

448                              insert the result 4.718 m.s^-1 into the equation editor

451, 452, 455, 456      same as for line 448

515                             same as for line 448

The researched topic will be a contribution to the professional discussion in the field of skydiving and creates preconditions and inspiration for further scientific work.

Author Response

Dear reviewer,

Thanks for your quality review, which definitely helped improve the quality of our article. I am attaching our cover letter.

Please see the attachment.

Kind regards

Author Response File: Author Response.docx

Reviewer 2 Report

Manuscript:

Research of the photo-optical method application for 3 measuring selected data on the movement of a parachute for 4 type M-282 Peter Kaľavský1*, Róbert Rozenberg 1 , Peter Korba 1 , Martin Kelemen jr. 1 Matej Antoško 1 Jozef Sabo 1 5 and Milan Džunda

 

Comments:

1. Suggest to separate the introduction section into

Introduction which only introduce the work and the motivation of the work and the literature review.

1. the theoretical background which should have the physical and mathematical formula and the relevant plots.

This will ease the reading and the following of the ideas and this is he typical trac in the publications.

 

2. introducing type M-282 123 Parachute or at least site the original reference for describing this type of Parachute .
3. in equation 1 (rH – air density in the height H [kg.m-3 58 ]) is misleading. Either the rH – air density should be treated as constant and taken into the account the average, or taking as a function of height as following r_H(H) and then also g is a function of height g(H). then equation 1 has to be corrected according to your assumption.
4. References 9 and 10 are not really the proper citation for this work, there much more relevant text book specialist in this work and no need to use website with poor information as a references.
5. Figure 1 has no citation, and it is in poor resolution.
6. Capital letter should be used after starting the pullet paragraph. This point also valid for many other sites where capital letter has to be used.
7. (1.1 Measurement of the vertical parachute speed using the classic method) should be as title not regular text.
8. Figure 2 and Figure 3 have no citation, and it is in poor resolution.
9. Sections 2.1., 2.2. and … 2.7. need to have title and treated as head section.
10. Figure 4 and figure 5 should be in one plot with a and b because they are connected. They are also in poor resolution. Additionally, they miss citation.
11. Figure 6 and Figure 7 also can be merged in one plot (a) and (b) and more appropriate caption. Citation also.
12. Equation 10 should be considered in equation 1 from the beginning and reduce the unnecessarily theory because this from text book and then focus on the goal of the manuscript.
13. In table 3, physical units are missing for some parameters and also somewhere else in the manuscript.
14. For experimental work, real photos of the parachutes and the equipment (cameras and detectors) used in the experiment can be shown with annotation.
15. In the experimental parts the device and the sensors have to be explained and the source of them as well. Authors should be able to provide their own schematic diagram of the experiment. To provide some originality for the work.
16. Some sentence in the discussion are out of any message to the manuscript such as (The classic method [16,26], and the barograph [13] or FLYTEC 4030 [26] methods, 642 also have advantages and disadvantages.). Filling sentence should be removed to focus on the goal of the work. Ambiguous sentences also should be clarified.
17. Conclusion is lengthy and does not answer the novelty and applicability of the work in direct manner.

I recommend to stress in showing the novelty of the work. The new things.

I also recommend to remove the well-known straightforward parts or shift it to supplementary of the manuscript, since this lengthy well-established theory is defocusing the work.

 

I recommend to accept this manuscript with major revision

Comments for author File: Comments.docx

Author Response

Dear reviewer,

Thanks for your quality review, which definitely helped improve the quality of our article. I am attaching our cover letter.

Please see the attachment.

Kind regards

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

1. In the experimental parts the device and the sensors have to be explained and the source of them as well. Authors should be able to provide their own schematic diagram of the experiment. To provide some originality for the work.

2. I recommend to stress in showing the novelty of the work. The novel approaches.

3. most of the figures have no citation, and it is in poor resolution.

Author Response

Dear reviewer,

Thanks for your quality review again, which definitely helped improve the quality of our article. I am attaching our cover letter.

Please see the attachment.

Kind regards

Author Response File: Author Response.docx