Multi-Monostatic Interferometric Radar with Radar Link for Bridge Monitoring

Round 1

Reviewer 1 Report

The article proposes a multi-monostatic interferometric radar with radio link to measure two-dimensional bridge deformation. The research is very interesting and of practical value in the bridge health inspection application. However, there are some key issues to be made clear before the manuscript be accepted, to maintain the high quality of the journal.

1 Two-dimensional displacement measuring precision verification

The result in the controlled experiment is not objective and proper. The main displacement component is along the z-direction. However, the component along the y-direction is also notable (≈1mm visual estimated). The value is large than the practical engineer requirement. The authors use the mean value as a precision indicator. It isn’t proper, as the mean value of an oscillating curve is 0, in theory.

2 System issues

2.1 The radio link is composed of a receiver and a transmitter. The direct coupling from the transmitter is usually much larger than the backscattering echo. How to prevent self-excitation when amplifier magnification is large?

2.2 The positions of radar and transceiver have a great impact on the precision of the two-dimensional displacement. The authors should compare the experiment result with the theoretic value.

3 Measuring point registration of the two radar images

Registration of the two one-dimensional radar images is a tough task, especially in a real scene. There would be many large scatters along the range direction. The backscattering property would be notably different from the two view directions. The authors also mention this problem in line 52. How do the authors solve the problem?

4  Manuscript details

4.1 Are Figure3 and Figure4 illustrated in the same coordinates? It seems they aren’t, and this would lead to misunderstanding. The components in Eq.(1) and Eq.(2) are not described.

4.2 Parameters in the controlled experiments are not clear, i.e., the values of G and RCS.

5 Discussions

The authors measured two points of the Indiano Bridge; can the performance be further improved? As I know interferometric radars can measure multiple points at the same time. However, the backscattering points in the two radar images do not quite match (large scattering peaks are within 100m). The authors had better give some advice to improve the performance.

Author Response

The correction report is in the attacched file

Author Response File: Author Response.pdf

Reviewer 2 Report

This research work is very interesting and concerns the presentation of a multi-monostatic radar with radio link. The authors have verified this approach in a controlled environment.
I recommend the publication of this work with some minor issues:
-Can multi-monostatic interferometric radar be used regardless of the length of the bridge? Or are we limited?
-How can we improve the number of targets detected by the radar?

 

Author Response

The correction report is in the attacched file

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thanks for your dedicated work to improve the manuscript. 

Author Response

Thank you