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The manuscript develops a method for generating a global seamless daily 9-km L-VOD product from 2010 to 2021. This product effectively fills gaps in the original VOD data from SMOS and SMAP while maintaining temporal and spatial consistency with the original L-VOD products. The topic is well suited for ESSD, and the results are of significant interest. However, there are some concerns regarding the performance of the reconstructed VOD. The manuscript could be suitable for publication after the authors address the general and specific comments provided below.

General comments

1. A more detailed discussion of the results would strengthen the manuscript. In particular, further analysis of the performance of the new product across different land cover types would be beneficial. Additionally, evaluating VOD against vegetation-related parameters, such as aboveground biomass (AGB), NDVI, and LAI, would enhance clarity.
2. It may be helpful to consider measures to reduce the bias between SMOS VOD and SMAP VOD, as this discrepancy could impact the accuracy of the fused product. A more detailed analysis of this uncertainty would be valuable.
3. The overall readability of the manuscript could be improved, particularly in terms of phrasing, organization, and paragraph structure. The authors may wish to have the manuscript reviewed by a native English speaker to refine grammar, style, and syntax.

Specific comments

1. Page 4, line 191. Define “IGBP, UMD and LAI” before their first use.
2. Page 5, line 220. Define “DCT-PLS” before its first use
3. Page 7, line 288. The bias between SMOS and SMAP products should be considered (e.g., 10.1016/j.rse.2022.113272). This addition is relevant and could significantly broaden the manuscript's appeal.
4. Page 7, Line 313. Please consider adding a more detailed description of the spatiotemporal fusion experiment. This should include the relationship between the reconstructed SMOS VOD and reconstructed SMAP VOD, the division of time segments, and the relationship between the fusion product and the reconstructed SMOS VOD and SMAP VOD.
5. Page 12, Fig. 7. The text in this figure is too small.
6. Page 13, Fig. 9. Please explain why the reconstructed products were more blurred than the original product.
7. Page 19, Fig. 16. Discuss the reseason of white pixels over land in VOD_st winter.