This manuscript presents a novel data-driven approach for calibrating scaling parameters used in cosmic-ray neutron sensing (CRNS) for soil moisture measurements. The work makes a meaningful contribution to improving CRNS methodology, though there are some aspects that would benefit from revision. For example, more detailed discussion of the practical implementation of the new approach can be made, what the implications of the new methods for CRNS users can be discussed.

The manuscript is well-structured and generally well-written, though some sections could be more concise and clear. The abstract could better highlight the quantitative improvements achieved over existing methods, the current version of abstract lacks detailed descriptions using some values. In the  methods section, I think it would benefit from a general paragraph summarizing what it takes to complete the calibration using the new method, maybe a flowchart can be added.

In all, this paper represents a valuable contribution to the field and is suitable for publication in HESS after moderate revision.

Specific line-by-line comments:

Lines 87-93: The objectives should be stated more explicitly here. Consider put specific research questions and objectives at the beginning.

Lines 315-324: The sensitivity analysis results could be more quantitative when describing impact of parameter variations on soil moisture estimates. Consider refer to specific values (sometimes can be in brackets after your statements) in this section.

Grammar Issues:

Line 74: “effect” to “affect”

Line 142: Missing space after abs_ref

Line 330: “Contour lines show soil moisture differences of 0.00 and 0.02 m³/m³ to reference values.” Consider rephrasing to avoid ambiguity

The manuscript presents a novel approach to calibrate CRNS for soil moisture estimation using a data-driven, inverse modeling technique. This method promises to address site-specific and sensor-specific variations that are often overlooked in traditional analytical methods. The idea is innovative and highly relevant to the field. However, there are several areas where the manuscript could be improved:

Comment:

1. The manuscript briefly talked about traditional analytical methods, but including additional details about these in methodology section would enhance its comprehensiveness. A short summary or explanation of how traditional methods are practically implemented, alongside their limitations, could enrich the manuscript significantly. Similarly, further clarification on the forward model used in the inverse method (possibly included in response to the first reviewer's comment) would be beneficial. This inclusion should highlight how analytical method calculate the soil moisture and how the newer approach will calculate. These short or one paragraph would be especially helpful for new readers to better understand the methodology.

2.The abstract could be improved by adding the exact results. Specifically mentioning the strong correlations and higher variability. 

Overall, the research article is well-written and presents a novel and valuable contribution to CRNS calibration methods.