Multi-Spacecraft Tracking and Data Association Based on Uncertainty Propagation
Round 1
Reviewer 1 Report
In this work, This paper proposed a multi-spacecraft tracking and data association method based on the uncertainty propagation. A second-order state transition tensors (STT) are proposed for measurement prediction. The proposed method is applied into solving an angle-only four-spacecraft tracking problem. Furthermore, simulations show that the data association accuracy of the proposed method is higher than 99.99%.
some results in this work are novel. Moreover, they are incremental improvements of earlier results. The level of difficulty and originality of these results makes them suitable for publication. The mathematical steps seem to be correct, however I don’t revise all constructions. The experts in this field of space science will appreciate some technical progress exposed in this work. But there are some minors remarks
· 1. The authors have to shed light on the similarities and differences among their work and the literatures of the problem. A clear explanation, what is the new result in their work, and how it is build up upon previous work in the field.
· 2. The introduction can be improved
· 3. Line 89: J2 is the coefficient of Earth’s J2 term.: this sentence must be rewritten properly as “ J2 is the even zonal harmonic coefficient of Earth which identify the oblateness effect”
· 4. A conclusion section should be extended to include more details
In general, the authors have to describe in more detail the purpose of their study and its original contents. If the authors submit a modified version according to my suggestions where they also give more details/explanations about the abovementioned criticisms, I could recommend the paper for publication.
Author Response
Please see the attached file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The work is certainly of interest. The work fits the theme of the journal. Comments and suggestions:
1. Section 2 would certainly have been more illustrative if the authors had added a figure with the coordinates used in the dynamic equation.
2. After formula (20) you write: "According to Ref. []..." . What reference? Specify it.
3. After formula (28) you write: "A lot of approaches have been proposed to cope with the task allocation problems, which can be broadly divided into the centralized ones and decentralized ones." Add references.
4. Section 4 should be expanded. Show not only the beginning and the end of the simulation. Show how your algorithm works. It is not very clear from the presented results.
5. In the explanations of formula (38) the designation of the zero matrix is missing.
Author Response
Please see the attached file.
Round 2
Reviewer 2 Report
I believe that the authors have done a great job in improving the quality of the material in the article. They responded to all questions and comments. The article can be published.
