Review Reports

Round 1

Reviewer 1 Report

In this paper, an extended PFA (EPFA) is proposed, the mapping functions is re-derived and the phase compensation function is used to eliminate the wavefront curvature error. From my point of view, the work is well-done and effectively solve the problem that the CPFA’s depth-of-focus (DOF) is small for high-resolution highly-squinted (HRHS) SAR. Some suggestions are as follows:

1. Line 60, explicit explanation of PFA is incorrect.

2. Explain the definition of  in equation (2). 

3. The curvature error caused by the traditional ranging model seems to be obtained from equation (2), can the in equation (2) be expressed more specifically?

4. in equations (16), (17), and (19) has not been introduced before, is it consistent with a certain vector in Figure 1? If yes, please unify the format. If no, please explain.

5. Some symbols in your manuscript are inconsistent, please check and revise.

6. The FFBPA is used for comparison with respect to the computational load. It is noted that the use of BPA is suggested for airborne SAR data with a better result. Thus, the authors should give more descriptions or analyses of FFBPA in this paper to avoid confusions. Moreover, references corresponding to FFBPA should be added

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Please see the atteched file.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf