Free webinar

Mine Site Surveying Pitfalls and Errors

Date: 07 July, 2020

Duration: 1 Hour

Time: 10:00 am PDT (Check the exact time and date in your city here.)

Presenter: Gerry Mitchell, P. Geo

In Partnership with:


The course will review the most common mine site surveying pitfalls and errors that PhotoSat has recognized and analyzed, over the years, when performing several hundred mine site surveys.  Accurate survey data is essential for confirming that the mine site earthworks construction conform to the re-engineering designs.  This is especially true for mine tailings facilities.  The investigation report on the  2019 failure of the Brumadinho tailings dam states the following:

 “Topographic data, which show the physical state of the facility at the time of the survey, tend to be the most valuable source of information when examining construction history.”

This course will be particularly relevant for Responsible Tailing Facility Engineers, Engineers of Record, Senior Technical Reviewers, Members of Independent Tailings Review Boards and all managers and engineers with responsibility for mine site earthworks stability and safety.  They will benefit by learning how to recognize the most common types of mine site survey errors.

Course Outline

  • Detecting and measuring mine site survey errors using Satellite Surveys. 
  • Examples of errors in mine site GPS, LiDAR and drone surveys.
  • Discussion of mine site survey errors with the following causes:
    • Different survey benchmarks with vertical offsets from each other
    • Incorrect or unknown vertical references
    • Custom mine grids with poorly defined transforms from GPS geographic coordinates to the mine grid coordinates
    • Custom geoids


Gerry Mitchell

Gerry Mitchell, P. Geo – President and Founder of PhotoSat

Gerry Mitchell is a Registered Professional Geophysicist of the Province of Alberta and a registered Professional Geoscientist of the Province of British Columbia.

Gerry has worked at the senior technical level in both mining and hydrocarbon exploration. He was BP Canada’s Senior Mining Geophysicist for Canada in the early 1980’s, and BP’s Senior Seismic Specialist for West Canada Basin Oil and Gas Exploration in the late 1980’s.

In the early 90’s, Gerry worked as a Remote Sensing Specialist for Frontier and International Oil and Gas Exploration in BP’s head offices in London England.

Gerry left BP in 1993 and founded PhotoSat in Vancouver. Since that time PhotoSat has carried out satellite surveying and mapping projects for several hundred companies and government agencies throughout the world.

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