Search Strategy for Buried Objects in Water: Geophysics, Probes and Dogs

Round 1

Reviewer 1 Report

An interesting paper, clearly written by authors with an extensive knowledge of the area.  This paper is very practical, and therefore is a valuable contribution to the literature.

One small point in terms of presentation, the arrows on figure 2 are hard to see.  I suggest changing them and making them more obvious.

Author Response

Reviewer 1. Many thanks for your enthusiasm. The arrows on Figure 2 are now increased in weight from 0.25 to 0.75: we hope these are now much clearer.

Reviewer 2 Report

Report on the paper

Search Strategy for Buried Objects in Water: Geophysics, Probes and Dogs By Alastair Ruffell  Neil Powell

Line 26 there is a change of line that is a mistake.

Line 36 is it “the Issue” or as it is “The Issue”

Legend and dimensions in Figure 1. The numbers are very difficult to see and read and is it possible to add a colour scale? Or explain the meaning of the colours?

In Fig. 2 there are no unities in the Y axis. Could be twt or metres.

In figure 2 what are A,B,C,D, CF. Can you tell us something more about the nature of the anomalies you point out?

In Fig. 3 what are the x axis dimensions?

What is figure 2019 in the legend of  fig.3?

Is it a question mark at the end of line 81?

There is no scale and northing in Figure 4

Figure 6 no dimensions or  indication of unities in the Y axis

Regarding the use of GPR or rather WRW for these aims please give some indication or recommendation for the operation procedure that is, continuous or discrete reading, speed of the WRW, staking, sampling rates, etc. Just some general indications please. Once you do this please complete with some comments based on your experience.

It is true that the use of WRW in brackish water is not advisable as the conductivity of the medium prevents the signal to propagate. Can you give us more details on the limits of the water conductivity  to use the WRW?

Is it possible to add  a flowchart depicting the operations or better the sequence of operations and methods you propose?

Regards

Author Response

Line 26 there is a change of line that is a mistake.

- Corrected

Line 36 is it “the Issue” or as it is “The Issue”

- Changed to "the problem" for clarity

Legend and dimensions in Figure 1. The numbers are very difficult to see and read and is it possible to add a colour scale? Or explain the meaning of the colours?

- We went into the Sonar setting and made an output with larger font numbers - hope they are clear now (they can be made bigger, if the Editor wishes); colour scale added with caption explanation.

In Fig. 2 there are no unities in the Y axis. Could be twt or metres. Actually 'm' is shown at the top of the Y axis: however, this raises a good point of what the TWT is

- so we have added this on the right-hand Y axis, for accuracy: thanks.

In figure 2 what are A,B,C,D, CF. Can you tell us something more about the nature of the anomalies you point out?

- Excellent comment, thanks. Nature of each anomaly added.

In Fig. 3 what are the x axis dimensions?

- Trevor Winton (Flinders Uni., Australia) has kindly provided his sonar data, which we have modified and used for Figure 3: this shows both X and Y axis dimensions.

What is figure 2019 in the legend of  fig.3?

- Now not needed, see above (clearer figure without old annotations).

Is it a question mark at the end of line 81?

- no, no question mark needed.

There is no scale and northing in Figure 4

- as we stated in the figure caption "no accurate scale is given to avoid location details". Nonetheless, we have checked with the search authorities, and a rough scale and cardinal point (N) is acceptable to them. We thank Reviewer 2 for prompting us to do this - makes it more accurate.

Figure 6 no dimensions or  indication of unities in the Y axis

- 'm' added and the TWT in ns.

Regarding the use of GPR or rather WRW for these aims please give some indication or recommendation for the operation procedure that is, continuous or discrete reading, speed of the WRW, staking, sampling rates, etc. Just some general indications please. Once you do this please complete with some comments based on your experience.

- An excellent comment from Reviewer 2, for which we are grateful and have added a bulleted Section 4 (Recommendations) to address this.

It is true that the use of WRW in brackish water is not advisable as the conductivity of the medium prevents the signal to propagate. Can you give us more details on the limits of the water conductivity  to use the WRW?

- This is correct: a great question not easily answered. My former PhD student, Rachael Parker did a lot of work on this by floating WPR boats from fresh to brackish water and in water tanks: she unfortunately passed away before completion, but there is a whole research project on this subject, as the diminution of radar penetration is gradual, depends on mixing and the halocline. We added a line on seawater/brackish water, but cannot adequately address this comment in this work for the above reasons - it is a huge and complex topic.

Is it possible to add  a flowchart depicting the operations or better the sequence of operations and methods you propose? Added in Section 4 on Recommendations

- a fantastic idea from the reviewer.

Round 2

Reviewer 2 Report

Dear Authors,

Thank you very much for going through my comments and suggestions.

It is my opinion that the work can be published now.

Regards