Measurement Method for the Flight Parameters of a Small Flying Object Using a Multi-Dimensional LED Detection Array
John S. Mitchell
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe paper by Dong et al. deals with a new method based on a multi-dimensional LED detection array, in the framework of flight-parameters measurement. By means of geometric manipulations, numerical simulations and empiric comparisons, the roles of two different reference velocities and of a range of pitch-swing-azimuth angles are investigated. After recalling the progress achieved and the difficulties met in this application, and introducing the layout of their proposed apparatus, the authors state the theoretical equations governing the problem, and perform a computational analysis on standard-rifle projectiles. Focusing then on the experimental counterpart, they study the dispersion of the impact points in the target plate, and express the feasibility and correctness of their approach. Their results are carefully presented and plotted, and the relevance of these findings with respect to the existing bibliography from scientific literature is thoroughly discussed.
In my opinion, the article deserves publication on Photonics. Hereafter I only mention few minor issues, to be addressed by the authors.
1) Text after equation (4): the quantities $i$,$j$,$k$ must be written in boldface (as well as $r$ just after equation (10))
2) Equation (8): the square brackets have a very bizarre form, please adjust it.
3) First two paragraphs of section 3.1.1: there are a lot of useless repetitions
4) First line of page 7: LS1 -> LS_1
5) Table 5: kindly avoid the splitting on two different pages
6) Page 14, fourth line: a word is mistakenly barred
7) Page 14, ninth and tenth lines (four times in total, counting also a later instance in section 5): "the maximum that of" ???
8) Page 14, eighteenth line: "To avoid the long length of" -> "To avoid an excessive length for"
9) Page 14, twenty-first line: the authors should give more precise details about the comparison "is more"
10) Section 5: the first sentence lacks of the main verb
Comments on the Quality of English LanguageOK
Author Response
Response to Reviewer
Dear reviewer,
We are great grateful for your professional review. As a beginner, I feel very sorry for the poor grammar quality of the original manuscript. We try our best to improve the manuscript and here we marked in red in the revised paper. We sincerely appreciate the warm work of editors and reviewers and hope that the correction will meet with approval. Point-by-point responses to your comments are listed below this letter. In addition, there are some errors that you cannot found, and I have also revised them according to some suggestions from my supervisor. Thanks again for your careful work, I greatly admire your academic rigor, and this will also help me to greatly improve our ability to write scientific papers in the future
Response to Reviewer 1 Comments
Comment 1: Text after equation (4): the quantities $i$,$j$,$k$ must be written in boldface (as well as $r$ just after equation (10))
Response 1: We appreciate your comments. The font used for these quantities in the original manuscript is Palatino Linotype, formatted in bold. We are not sure if "boldface" refers to a different font.
Comment 2: Equation (8): the square brackets have a very bizarre form, please adjust it.
Response 2: Thank you for your careful reading of our manuscript. We have rewritten Equation (8) according to your your comments.
Comment 3: First two paragraphs of section 3.1.1: there are a lot of useless repetitions
Response 3: Thank you very much for your careful reading of our manuscript. We feel sorry for our carelessness. In our revised manuscript, these duplicates have been removed (page 6, line 23-28).
Comment 4: First line of page 7: LS1 -> LS_1
Response 4: We are really sorry for our careless mistakes. Thank you for your comments. In our revised manuscript, we have corrected the “LS1” into “LS1” (page 6, line 30).
Comment 5: Table 5: kindly avoid the splitting on two different pages
Response 5: Thanks for your careful checks. We are sorry for these carelessness. Based on your comments, we have corrected the placement of the table.
Comment 6: Page 14, fourth line: a word is mistakenly barred
Response 6: We feel sorry for our carelessness. The word that should have been deleted was unexpectedly retained. We have deleted it in the updated manuscript.
Comment 7: Page 14, ninth and tenth lines (four times in total, counting also a later instance in section 5): "the maximum that of" ???
Response 7: Thanks for your careful checks. We have corrected the "the maximum that of" into "the maximum deviation of". We hope this can address your concerns (page 14, line 24-28).
Comment 8: Page 14, eighteenth line: "To avoid the long length of" -> "To avoid an excessive length for"
Response 8: We sincerely appreciate the valuable comments. We have revised the text according to your suggestion and hope that it is now clearer (page 14, line 36).
Comment 9: Page 14, twenty-first line: the authors should give more precise details about the comparison "is more"
Response 9: Thank you for your careful reading of our manuscript. We sincerely apologize for the misspelling of "is not more than 1.5 mm" as "is more than 1.5 mm" which caused confusion in your reading. In our resubmitted manuscript, the typo is revised (page 14, line 39).
Comment 10: Section 5: the first sentence lacks of the main verb
Response 10: Thank you for your helpful suggestions. We feel sorry for our carelessness. According to your comments, we made some changes in this part (page 14, line 43-44).
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis manuscript reports the use of a multi-dimensional light-emitting diode (LED) array to measure critical flight parameters of projectiles to aid assessment of the risk of projectile damage to sensitive surfaces. The technology employed in this paper appears to provide a useful alternative approach to projectile mechanics measurements and the experiments are described in appropriate detail and critical data adequately summarised across different velocities. There are however a number of points that should be addressed by the authors to improve the quality of the manuscript and these are elaborated below (all points require changes the manuscript).
1. The manuscript needs to be extensively edited to correct deficiencies in grammar and syntax. Individual issues are too numerous to list but they impede comprehension and readability of the article.
2. Page 2 line 29 “It can form a larger test area easily . . .” Up to how large an area? Provide details here.
3. Page 2 line 30 “. . . requires the flying . . . the target surface.” Briefly expand on why the object needs to be perpendicular to the surface. Surely this is a very severe constraint on an acoustic method that would greatly limit its applicability.
4. Page 2 lines 37-38 “Then, the measurement . . . LED Detection Array.” This sentence does not make sense as worded. A relationship between the LED Detection Array and what?
5. Page 4 lines 4-6 “Based on some . . . 0.4 m, respectively.” It would be useful to mention the area in m2 of your coverage of the test surface.
6. Page 6 lines 39-42 “The firing pitch . . . standard rifles, respectively.” This text repeats details already given earlier in this section. Delete the repeated text.
7. Page 11 lines 10-11 “Through simulating . . . the target plane . . .” More details are needed here about the range of locations studied, e.g. how many locations, how they differed from each other, their distribution over the surface.
8. Tables 3-8. For absolute clarity, please state that the values quoted are averages across the 50 projectiles. Also, the presentation of the standard deviations is confusing. Are these meant to be standard deviations across replicates (n =50)? If so, then using which of the two techniques? If they are instead some kind of comparison between your system and the high-velocity camera system then explicate from which data these standard deviations were computed.
9. Page 14 lines 2-4 “The simulation results . . . at different pitches.” As worded, this sentence is fairly meaningless. “Meet the measurement” suggests it meeting certain quality criteria, which are not defined here. Reword the sentence to give it proper meaning.
10. Page 14 line 21 “. . . and the maximum . . . more than 1.5 mm.” Can you not be more specific about the maximum rather than just saying it is more than 1.5 mm?
11. Page 14 lines 25-27 “In the investigation . . . small flying object.” This sentence does not make grammatical sense and needs to be reworded.
Comments on the Quality of English LanguageThe quality of English in this paper needs significant improvement. There are numerous grammatical errors and instances of poor syntax that need attention to improve readability.
Author Response
Response to Reviewer
Dear reviewer,
We are great grateful for your professional review. As a beginner, I feel very sorry for the poor grammar quality of the original manuscript. We try our best to improve the manuscript and here we marked in red in the revised paper. We sincerely appreciate the warm work of editors and reviewers and hope that the correction will meet with approval. Point-by-point responses to your comments are listed below this letter. In addition, there are some errors that you cannot found, and I have also revised them according to some suggestions from my supervisor. Thanks again for your careful work, I greatly admire your academic rigor, and this will also help me to greatly improve our ability to write scientific papers in the future
Response to Reviewer 2 Comments
Comment 1: The manuscript needs to be extensively edited to correct deficiencies in grammar and syntax. Individual issues are too numerous to list but they impede comprehension and readability of the article.
Response 1: We sincerely appreciate your valuable comments. We are very sorry for the poor grammar and syntax quality of the original manuscript. In the revised manuscript, we have checked the spelling and grammar and tried our best to polish the language.
Comment 2: Page 2 line 29 “It can form a larger test area easily . . .” Up to how large an area? Provide details here.
Response 2: Thank you for your helpful suggestions. The acoustic target system can form a large test area by increasing the number of sensors and proper array placement. However, this means more inconvenience and cost. According to the literature [12], the acoustic target type B541 from MSI UK has a measurement accuracy of ±20mm when the detection area is 20m × 20m. We have added this detail in the revised manuscript (page 2, line 32-34).
Comment 3: Page 2 line 30 “. . . requires the flying . . . the target surface.” Briefly expand on why the object needs to be perpendicular to the surface. Surely this is a very severe constraint on an acoustic method that would greatly limit its applicability.
Response 3: We appreciate your valuable comments. If a small flying object hits the surface of a target perpendicularly, this will cause the maximum damage to the protective material layer of the attacked target. Obviously, this can provide some scientific reference to improve the performance of the protective material. Generally speaking, the trajectory of small flying objects cannot be completely perpendicular to the protected target surface due to some disturbance factors. However, the measurement model of the acoustic target requires the projectile to be perpendicular to the target surface. The oblique incidence of the projectile can cause significant theoretical errors. We have revised the text to address your concerns and hope it is now clearer. See page 1 of the revised manuscript, lines 37-41, and page 2, lines 34-35.
Comment 4: Page 2 lines 37-38 “Then, the measurement . . . LED Detection Array.” This sentence does not make sense as worded. A relationship between the LED Detection Array and what?
Response 4: Thank you for your valuable suggestions. We apologize for the lack of clarity in this part. There is a certain spatial geometric relationship among six laser screens of the LED detection array. We have revised the text of this part and hope that it is now clearer (page 2, line 40-42 and page 3, line 16-17).
Comment 5: Page 4 lines 4-6 “Based on some . . . 0.4 m, respectively.” It would be useful to mention the area in m2 of your coverage of the test surface.
Response 5: Thank you for your constructive suggestions. The test area (about 1.1m2) of the laser screen is an isosceles triangle with a height of 2 m and an effective viewing angle of 30°. We have added details about the laser curtain test area to the revised manuscript (page 4, line 8-12).
Comment 6: Page 6 lines 39-42 “The firing pitch . . . standard rifles, respectively.” This text repeats details already given earlier in this section. Delete the repeated text.
Response 6: Thank you for your helpful suggestions. We feel sorry for our carelessness. In our resubmitted manuscript, duplicates have been removed (page 6, line 24-29).
Comment 7: Page 11 lines 10-11 “Through simulating . . . the target plane . . .” More details are needed here about the range of locations studied, e.g. how many locations, how they differed from each other, their distribution over the surface.
Response 7: Thank you for your careful review and constructive suggestions regarding our manuscript. In section 3.1, the systematic error simulation is performed at the center position of the target plane. The other positions are randomly generated around the center position with a Gaussian distribution. Through simulating other locations within the range of projectile dispersion in the target plane, it is found that the error distribution is consistent with the simulation results of the target center, and are not listed in the article. We have revised the text to explain it (page 12, line 1-7).
Comment 8: Tables 3-8. For absolute clarity, please state that the values quoted are averages across the 50 projectiles. Also, the presentation of the standard deviations is confusing. Are these meant to be standard deviations across replicates (n =50)? If so, then using which of the two techniques? If they are instead some kind of comparison between your system and the high-velocity camera system then explicate from which data these standard deviations were computed.
Response 8: Thank you for your valuable and thoughtful comments. We use some standard projectiles for our experiments, and their weight, powder charge, and shape are strictly controlled. The high-speed camera system has been strictly calibrated in advance with high accuracy, so its measurement results can be considered as reference data. The proposed system measurement data is compared with reference data to verify the feasibility and validity of the method. To obtain the standard deviation, the sum of the squares of the differences between the measured data of the proposed system and the reference data was divided by 50 and then square root. We have revised the text to explain it (page 12, line 12-13, line 17-18 and line 22-23).
Comment 9: Page 14 lines 2-4 “The simulation results . . . at different pitches.” As worded, this sentence is fairly meaningless. “Meet the measurement” suggests it meeting certain quality criteria, which are not defined here. Reword the sentence to give it proper meaning.
Response 9: Thank you for your instructive suggestions. The simulation results show that the system can theoretically achieve the measurement of |v| and impact coordinates of the small flying object at different pitches, and meet the test requirements [10,19,20]. We have revised this part according to your suggestion (page 14, line 19-21).
Comment 10: Page 14 line 21 “. . . and the maximum . . . more than 1.5 mm.” Can you not be more specific about the maximum rather than just saying it is more than 1.5 mm?
Response 10: Thank you for your careful reading of our manuscript. We sincerely apologize for the misspelling of "is not more than 1.5 mm" as "is more than 1.5 mm" which caused confusion in your reading. In our resubmitted manuscript, the typo is revised (page 14, line 39).
Comment 11: Page 14 lines 25-27 “In the investigation . . . small flying object.” This sentence does not make grammatical sense and needs to be reworded.
Response 11: Thank you for your instructive suggestions. We feel sorry for our carelessness. According to your comments, we made some changes in this part (page 14, line 43-44).
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors have made satisfactory changes to the manuscript to address points raised in my earlier review. There are still issues with grammatical errors in the manuscript that could do with correction as part of the editorial process.
Comments on the Quality of English LanguageThe quality of English in this manuscript is minimally passable but there are still issues with grammatical errors in the manuscript that could do with correction as part of the editorial process.
