Statistical Approach to Research on the Relationship Between Kp/Dst Geomagnetic Indices and Total GPS Position Error
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe comments can be found in the attached file.
Comments for author File: 
Comments.pdf
Author Response
The comments can be found in the attached file.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors make a research of the impact of geomagnetic disturbances on the accuracy of single-frequency GPS positioning. They chose areas in equatorial and mid-latitude regions (approximately ±45°), where electromagnetic interference is generally the least. However, the results of the analysis of variance confirm that the variation of the total GPS positioning error is non-random and can be attributed to the influence of geomagnetic storms. The results of the developed methodology can find application in sectors such as navigation, timing services and geospatial monitoring. The methodology and the results obtained are well explained and presented. My only comment is that the authors could expand the conclusion more and include the results and conclusions that are important to them.
Author Response
The comments can be found in the attached file.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authors- For a better understanding of space weather parameters, it would be necessary to present the time series of the Kp and Dst indices for the period September 4-11, 2017 on a separate graph.
- The authors state that “while an absolute statistically significant improvement in GPS position accuracy from 0.35 cm to 2.18 cm was achieved”. From this statement, the positioning accuracy degraded instead of improving.
- The authors state that “…initial settings for determining total GPS position error are shown in Table 2”. In Table 2 we read: Ionosphere correction – Broadcast. This means that the influence of the ionosphere was corrected using the Klobuchar model. Does that mean that all further research concerns the accuracy of Klobuchar model which is applied to GPS single-frequency positioning?
- This study attempts to establish whether the statistically measurable influence of the selected geomagnetic indices affects the accuracy of single-frequency GPS positioning. If we are talking about the statistics of a complex interaction process, is it appropriate to use only the September 2017 event?
- The reviewer did not find a reference to [49] in the text of the article. What was the point of citing it? [49]: J. Klobuchar, Ionospheric Time-Delay Algorithm…
- It is known that the analysis of variance ANOVA is designed for use when the observations are drawn from a normal distribution. Can it be assumed that observations during periods of solar and geomagnetic activity are subject to the normal law of distribution? To rectify this problem, researchers need to modify their data or may have to resort to other techniques.
- ANOVA is helpful but does have some limitations that can impact its findings: a) that the data for each group are normally distributed; b) that ANOVA needs the variances in each group to be the same, which is referred to as the homogeneity of variance; c) that the data points are independent, i.e., one data point should not influence another. The authors did not analyze these limitations in relation to their data, but the general description, which is still known to students, was given in sufficient detail.
Author Response
The reply can be found in the attached file.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors took most of the comments into account in the new version of the article.
The authors' position on remark 3 is not entirely clear
3. The authors state that “…initial settings for determining total GPS position error are shown in Table 2”. In Table 2 we read: Ionosphere correction – Broadcast. This means that the influence of the ionosphere was corrected using the Klobuchar model. Does that mean that all further research concerns the accuracy of Klobuchar model which is applied to GPS single-frequency positioning?
