Research on Detection Technology of Spoofing under the Mixed Narrowband and Spoofing Interference

Round 1

Reviewer 1 Report

Dear Authors,
your work has been deeply amended since the first revision, also in agreement with my suggestions.
I propose to accept it in this form.
Kind regards

Author Response

Many thanks to the reviewers for acknowledging our work.

Reviewer 2 Report

The contents of article are interesting and in line with the objectives of the topic. In the revised manuscript the description of the experiments has been improved and minor remarks have been fixed by authors.

Despite this, the paper still needs further improvements in order to be published in the Journal.

Discussion section is very short, in this section the authors should describe what advantages the adoption of the indicated methodology allows in both a qualitative and quantitative way. It is not enough to just say that their methodology :” significantly improves the detection performance of spoofing interference”.

Furthermore, in my opinion it should be better specified which contribution is added by the authors in the treated area comparing their methodology with the others already used in the literature and highlighting the differences between them.

Minor remarks

A large number of literatures have analyzed the influence of frequency-domain anti-jamming on the correlation peak of the navigation signal, and its influence is related to the interference frequency, bandwidth and other factors.

References have been added but authors should add in the text some hints to what is done in the articles cited [40,41].

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors did not respond to all reviews. In particular, I refer to this:

In my opinion it should be better specified which contribution is added by the authors in the treated area comparing their methodology with the others already used in the literature and highlighting the differences between them.

Author Response

Please see the attachment

Author Response File: Author Response.docx

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Manuscript Number: remotesensing-1638105

Full Title:  Research on Detection Technology of Spoofing under the Mixed Narrowband and Spoofing Interference

The Technical Note submitted to Remote Sensing MDPI by Long Huang et al. studied the problem of spoofing interference detection under mixed interference conditions, and proposes a spoofing interference detection method based. The paper is analyzed in original submission and is structured in: 1. Introduction, 2. Mathematics Model, 3. Analysis of the influence with interference, 4. Detection method based on correlation peak symmetry, 5. Experimental verification of software receiver, 6. Conclusion, References.

With regret, I cannot recommend publication in this form, because I have to note that the work was not submitted with reference to the authors' instructions, which required an article length of at least 18 pages for submissions to RS (the paper is only 16 pages).

After, articles on RS usually start with Introduction, Materials and Methods, Results, Discussion, Conclusions, and so on. There is no firm standard way of writing an article, but the article should be readable by people in this field. Material and methods are partially described in section 2, 3 and 4.

Discussion section is also missing.

In relation to the previous points, I would like to advise the authors to deeply modify the structure of the work as follows:

1. read the authors' instructions and set up the paper according to the following scheme: Introduction, Materials and Methods, Results, Discussion, Conclusions;
2. the Discussion section (missing) is mandatory in RS and must be written in depth so that readers understand the importance of the study.

I will be available to authors for the assessment of the manuscript at the subsequent submission, in which I reserve the opportunity to elaborate on the remarks from the scientific point of view of the technical note.

Best regards

Reviewer 2 Report

My comments for Authors:

1. abstract, please add obtained results from research test for underline your solution.
2. introduction, please add more information about novelty of paper, why your new method is important with reference to scientific knwoledgde analysis?
3. all acronyms must be expalined, e.g. SCB
4. I don't see discussion part, please compare your solution with scientific knowledge analysis (e.g. papers from References). Why your solution is better? 
5. conclusion, please add information about obtained results from research test for underline your solution.

Reviewer 3 Report

Dear authors,

Please find several remarks below. 

• Authors should provide more detailed (specific) info on types of intentional interferences, including meaconing, which has several touching points with spoofing. 
• Also, it is not clear which GNSS was used (one, combined, all?...), and perhaps the positioning method/type of receiver should be stated (in methodology). 
• The English expression should be improved in a more scientific manner; 

 - e.g. text accompanying Eq. (2): 'The real signal expression looks like this:'

 - e.g. 'The spoofing interference detection and spoofing interference is a process of mutual game, ...'

• The paper should be revised and redundant phrases have to be omitted. 

 - e.g. The same phrase is repeated through the Conclusion chapter (first and last sentence). 

Reviewer 4 Report

The contents of article are interesting and in line with the objectives of the topic. The manuscript must be strengthened above all in the description of the experiments and better detailing the conclusions that can be drawn from the experiments. Furthermore, in my opinion it should be better specified which contribution is added by the authors in the treated area.

Following same minor remarks

Page 3 please correct typo The dynamic in lower case

Figure 5 please impreve quality, it is clearly visible that it is a cropped image and not generated

Page 7

A large number of literatures have analyzed the influence of frequency-domain anti-jamming on the correlation peak of the navigation signal, and its influence is related to the interference frequency, bandwidth and other factors.

Please add references

Experimental verification of software receiver

Please improve this sectionby better describing how the experiment was performed. For example what software were used?

Figure 14 please you should add what the colors in the graduated scale represent.