A Survey for Recent Techniques and Algorithms of Geolocation and Target Tracking in Wireless and Satellite Systems

Round 1

Reviewer 1 Report

Overall, this is a very nice survey focusing on tracking for geolocation purposes via the wireless medium. Still, before publication, it is my opinion that the following major comments should be addressed by the authors:

1)    Due to the large number of acronyms involved, it would be very useful providing a table collecting all them.

2)    Sec. I – Please enrich and detail the statement of contributions.

3)    In Sec. I, I would like to provide a brief discussion on related surveys tackling the same/similar topic to better position the present study. Also, a complementary table to support this discussion would be quite useful.

4)    When discussing RSS-based techniques, the authors may also want to recall its widespread use in WSN-based detection/localization:

"Generalized Rao test for decentralized detection of an uncooperative target." IEEE Signal Processing Letters 24.5 (2017): 678-682.

"Detection of a non-cooperative transmitter in Rayleigh fading with binary observations." MILCOM 2012-2012 IEEE Military Communications Conference. IEEE, 2012.

"Distributed detection in wireless sensor networks under multiplicative fading via generalized score-tests." IEEE Internet of Things Journal (2021).

5)    Sec. 3.5 – Please provide a few references dealing with PDOA.

6)    It would be very interesting if the authors could report a section where possible open datasets (containing real data) for geolocalization are listed and discussed.

7)    In conclusion section, I would like the authors to provide a paragraph highlighting what they consider to be open challenges in the field.

Author Response

Dear Reviewer,

Good day

Please see the attachment, (The response letter)

Best regards 

Abulasad

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is a survey, focused on geolocation, tracking, as well as wireless and satellite systems. Overall, the paper is written in proper English, it has a good structure and is pleasant to read. Presented graphical elements are understandable, yet some should be inserted in larger size and/or with larger fonts. Tables are clear and informative.

As pointed out by the Authors, previous surveys did focus on (most often) just one aspect, being either wireless techniques, satellite systems, positioning/tracking, etc. Currently, since GNSS and GIS-related aspects became interdisciplinary, an additional (geolocation-centric) survey would seem most appropriate.

Displayed equations and mathematical formulas seem plausible and free of error. They are centered and enumerated. Symbols and/or vectors are prepared in such a way, in order to be easily distinguishable from plain text. However, some minor errors are present.

Obviously, the manuscript has a review character. The number as well as quality of cited references is good, however some issues should be covered better.

Overall, it is clear that this work took a lot of effort. It is a good paper, but it deserves to be a very good one. In order to meet those requirements, modifications are necessary. Due to the number of issues, it requires a major revision before it can be published.

Suggestions and comments:

• In the Title – write [Survey] with a capital [S], just like other nouns.
• 1, 4, 6, 7, 8, 9, 10, 17, 23, 24, 33, 34 (a) and (b) should be divided into separate ones (not presented in 1 row, but in 2 rows), so that they are simply larger, making it easier to read and interpret them. Otherwise, they should have larger fonts. The current form makes them illegible.
• On the other hand, Fig. 26 (a) and (b) have the right size, they look sharp and each element is legible.
• Since Authors mention broadcasting standards, including digital radio and television, it would be proper to cite some related papers.
• Extend the number of cited references on radiolocation, navigation and positioning methods.
• Carefully examine the whole manuscript for typos and spelling issues, e.g. [two approaches to solv[e]…] in line 70 on page 2.
• Check the paper for additional (unnecessary) multiple space signs – on multiple pages.
• Double-check whether the block diagram in Fig. 2 has the right format, resolution, dpi, etc., because the fonts seem to be blurred a bit.
• 12, 14, 15, 16 seem to be blurred as well.
• 18, 19, 20, 21, 22, 25, 27, 28, 29, 30, 31, 32 are too small, with too small fonts, and too low resolution, inappropriate file format, etc. – it simply looks blurred and is hard to read.
• Enlarge size and/or fonts in case of Figs. 3, 5.
• 13 – all fonts are large and easy to read, except the [object].
• When referring to particular Figures in text, write either [figure], [Figure], or [Fig.], and use one style throughout the whole paper.
• Equation (2) – what does p_e stand for? It is not written in italics, and there is no description in text.
• Line 182 on page 6 looks strange, it seems to be missing something – just the range of [i] with no description?
• It would be appropriate if the Authors would describe the DOP (Dilution of Precision) coefficient, including all its variations. This is particularly important in case of navigation/positioning with smart devices, particularly Android-powered ones.
• Table 2 on Page 17 – the citations [76, 78] should be inserted before the end of line sign. Carefully examine the whole paper for similar editorial/formatting issues.
• Authors could consider providing at least basic info on satellite formation, satellite constellations, principles and frequency bands of most popular GNSS.
• When writing that a particular figure was [adapted from], insert the proper citation [N] – see the difference in case of Fig. 21 (b).
• In case of Authors own graphs/plots, maybe it would be better to write [Authors own elaboration] instead of [Achieved by authors].
• The Conclusions section needs to be extended. After such a large survey, going through so much literature, etc., Authors surely have more thoughts and suggestions for the potential reader. Highlight your novel approach.
• The Future Works should be a separate chapter – it also needs to be extended. Discuss pros and cons of different methods, algorithms, devices, techniques, etc. What according to you needs to be updated. Which solutions lack e.g. precision or require big resources and/or high-computational power. Which of them, do to their complexity, can and cannot be realized in real-time.
• Check the current formatting of the References section and correct it according to the template and editorial requirements.

Author Response

Dear Reviewer,

Good day

Please see the attachment, (the response letter)

Best regards 

Abulasad

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Overall, this is a very nice survey focusing on tracking for geolocation purposes via the wireless medium.  The authors have satisfactorily addressed my previous comments and modified their manuscript accordingly. Hence, I am glad to recommend the present work for publication.

Reviewer 2 Report

Thank you for addressing to my review, including suggestions and comments. The revised version has improved the overall quality of the manuscript. Presented figures are much more legible and easier to read, interpret and understand. I believe that now the paper fulfils all necessary requirements in order to be published.

Yet still, some minor editorial and/or formatting issues are present:

• Indentation issues in the List of Acronyms, and some paragraphs (check lines 57, 741, 768, 796).
• Table 1 – sort those surveys from oldest to newest).
• Line 440 is blank.
• Do not begin a next paragraph (see line 445) with a citation – modify it to – In [100] Authors presented a position…
• Bullet points in Chapter 7 should be properly formatted. One (see line 786) is missing.

However, all of them can be easily overcome just before publication.

Overall, it is a very good paper, certainly interesting for a wide group of recipients. I will surely be one of the first readers of this Review after it will be published online on MDPI’s Applied Sciences webpage. I will also recommend this paper to my University Students.