Determination of GPS Session Duration in Ground Deformation Surveys in Mining Areas

Round 1

Reviewer 1 Report

The article is interesting for those who work in this area. Maybe the conclusions should be more detailed

Author Response

Thank you for the review.

Additional conclusions have been added

Reviewer 2 Report

The paper is well organised.

The introduction clearly contextualizes what the purpose and contribution is.

Interesting conclusions are presented in the paper that can be useful.

 

Author Response

Thank you for the review

Reviewer 3 Report

The proposed paper provides some suggestions for practical surveys in areas interested by mining induced subsidence.

Some minor amelioration can be done.

1) mention the fact that subsidence is linked to the type of orebody, shape, thickness, depth and recovery factor

2) the embedding rock properties and the overburden as well play a relevant role in the time lasting phenomena

3) discuss the accuracy of the control of ellipsoid of reference when changing method or over large areas, where some discrepancies could occur

4) correlate survey phases and duration of sessions with the excavation advancement

5) clarify the mesh / grid density necessary for a reliable assessment of the amount of subsidence, general or affecting local sensible structures.

6) check format before printing

Regards

Author Response

Thank you for the review.

 

Additional corrections have been made to the manuscript.

 

1) mention the fact that subsidence is linked to the type of orebody, shape, thickness, depth and recovery factor

- In the Abstract the information has been added linking the subsidence to the ore characteristics

2) the embedding rock properties and the overburden as well play a relevant role in the time lasting phenomena

- The description of the time lasting phenomena is given in Chapter 3

3) discuss the accuracy of the control of ellipsoid of reference when changing method or over large areas, where some discrepancies could occur

- it is written in the paper that in deformation surveys, the ellipsoidal and orthometric height differences between monitoring epochs are equal if the undulation stays constants

4) correlate survey phases and duration of sessions with the excavation advancement

- Additional chapter (Chapter 3) has been added describing the study area and correlation between survey phases and the progress of the extraction. The extraction took place at two levels. The extraction of upper level was completed in 1996. The extraction of lower level started in 2013. The investigated survey monuments HPN, ML4 and ML26 are located outside the deformation zone and serve as control points.

5) clarify the mesh / grid density necessary for a reliable assessment of the amount of subsidence, general or affecting local sensible structures.

- In additional chapter (Chapter 3) the density of the mesh of survey monuments is described. There are approximately 150 survey monuments. The average distance between monuments is approximately 200 – 300 m and is sufficient for the determination of subsidence

6) check format before printing

- Format was checked