A Survey of GNSS Spoofing and Anti-Spoofing Technology

Round 1

Reviewer 1 Report

I found this manuscript highly interesting. The different classification approaches of the GNSS spoofing and anti-spoofing technology are sufficiently described. The interferometry mode is also satisfactory. I only suggest that the authors add a few more sentences about the near and far future utilization of the vulnerabilities and the possible mitigations of this GNN spoofing research. 

Author Response

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Reviewer 2 Report

The paper “A Survey on GNSS Spoofing and Anti-Spoofing Technology” presents a review of recent work on the domain of GNSS based navigation safety focused on spoofing/anti-spoofing methods. The authors provide an in-depth overview of GNSS problematics and the design of a GNSS receiving system. They also offer some taxonomy for spoofing techniques and anti-spoofing methods. The paper is well organized and provides many useful details. However, it also has important flows as following.

1. There are a lot of typos, long phrases and inconsistencies along the entire manuscript. E.g. [25] “is susceptible to interferenc leads to the vulnerability of USE navigation system”, [35] “will usually degrade or completely degrade”, [37] “It will not be discussed in this paper[4].”!?, and very long and hard to understand sentences as [73] “Commonly, onboard receivers with receiver autonomous  integrity monitoring technology (RAIM) will use redundant signals to generate multiple GPS positioning and compare them by default, the purpose of this is to determine whether a fault is related to a signal according to statistical methods”

2. [53] It is not clear what is the meaning of the term “intentional interference”.

3. [91] “By analysing the current state of technological, we propose separate proposals for the development of spoofing and anti-spoofing technologies.” – it is not clear if the authors only present some existing work in the domain or they propose new methods, as this sentence suggests.

4. Reference to the source should be mentioned in the caption of Figure 6.

5. [243] Figure 7 in wrongly referred.

6. Figure 8 needs a legend in order to be interpreted. Moreover, it does not correspond to the description provided in text [329].

7. Important existing surveys and reviews in the domain are not considered/cited in the manuscript. E.g.

[r1] WANG, Wenbo, et al. A survey of spoofer detection techniques via radio frequency fingerprinting with focus on the gnss pre-correlation sampled data. Sensors, 2021, 21.9: 3012.

[r2] WU, Zhijun, et al. Spoofing and anti-spoofing technologies of global navigation satellite system: A survey. IEEE Access, 2020, 8: 165444-165496.

[r3] JUNZHI, Li, et al. Research progress of GNSS spoofing and spoofing detection technology. In: 2019 IEEE 19th International Conference on Communication Technology (ICCT). IEEE, 2019. p. 1360-1369.

[r4] XIAO, Ling, et al. GNSS receiver anti-spoofing techniques: a review and future prospects. Electronics, Communications and Networks V, 2016, 59-68.

Observation: The authors have to motivate why their taxonomies are better than those presented in [r2]. The [r1, r2] surveys seem to be much more comprehensive than this manuscript (e.g. the authors miss some interesting anti-spoofing methods as the one based on particle swarm optimization ARPSO, on maximum-likelihood power distortion monitoring PD-ML, and many others). Some state-of-the-art techniques, as the ones involving machine learning [r3] are also ignored by the authors.

8. No comparison is presented in term of performance of presented algorithms. No suggestion is provided on the type of application for which each of them is most suitable. 

Author Response

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Reviewer 3 Report

Dear authors, I reviewed the paper entitled “A survey on GNSS spoofing and anti-spoofing technology”. This paper makes a review of the satellite navigation spoofing and anti-spoofing technology proposing a classification of the different methods from different standards, analyzing and comparing them. It explains the research done and the state-of-the-art in this field of GNSS technology and proposes future directions. Nowadays, this field of research is speeding up thanks to the sophistication of the different techniques, algorithms, receivers, etc. From my point of view, this is an interesting review paper, well-structured, which exposes the spoofing and anti-spoofing technology and classification in a clear way, once the basics are presented in the first sections.

Revise the grammar along the manuscript as there are some typos in the text. For example, “we proposes” in line 10 or “can’t” in line 20. Or “anti spoofing vs. anti-spoofing”. There are many more.

Check line 551. Figure 11 vs. Figure 9.

Line 127. Remove the word “error”. Error and accuracy are opposite concepts.

Check the line after line 102 “can be obtained basis of the formula” sounds strange.

Line 211 and 216 -> Replace Reference [XX] with the name of the authors.

The names Huang Long et al. are not correct for reference 37 in line 221.

Line 243, check the number of the figure.

Lines 310-311. Ledvina et al. is not reference [44]. Revise all the references, including tables.

Table 2. Order the lines chronologically. Regarding Literature, add the name of the author/s before the reference number.

Table 4. Replace “Literatures” with “Literature”. Add the name of the author/s before the reference number.

Replace “Jafarnia-Jahromi” with “Jafarnia-Jahromi et al.” in line 584. The same in line 629. Revise all the names and references in general.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The revised version of the manuscript “A Survey on GNSS Spoofing and Anti-Spoofing Technology” corrects most of the signaled textual errors and typos. It also removes inconsistencies between descriptions and some figures. There are still some concerns about utility of this study compared with existing surveys. However, the purpose of the authors’ work is better explained now.