Resurvey Holes

Summary

Recalculates the drillhole trace locations for the current drillhole dataset from collar locations and survey table measurements (if present).

Usage

If any manual edits were made to collar location or survey measurement values (e.g. for an incorrect XYZ collar location value or Dip/Azimuth/Depth survey values), a "resurvey" needs to be performed in order to recalculate the drillhole trace locations and geometries/shapes, from the XYZ collar and dip/depth/azimuth survey data.

A "resurvey" happens automatically when the Import Drillholes or Refresh Drillhole Imports tools are used.

Technical Notes

Desurveying Drillholes using Collar and Survey Data

The drillholes are always "desurveyed" on import, which means a 3D spatial object (a drillhole "trace") is calculated for each drillhole. The output trace for any given hole can vary depending on what type of data is available during import (collars only, vs. collar and survey data) and which method is selected to do the desurvey calculations, as well as the resolution value selected. The various ways to calculate the traces, depending on which types of data are available, are described below:

With collar locations only, no survey data present:

  • If collar data includes dip and azimuth, these values are used to create straight segment traces for the entire hole, to the final depth.
  • If collar data does not include dip and azimuth, the holes are assumed to be vertical.

With collar locations and dip-azimuth survey data:

  • The survey data is "discretized" at the desurvey resolution interval value and a smooth curve is generated using the selected desurveying method (the default is the "Radius of curvature" method). See Drillhole Settings for more details.
  • Holes are 'desurveyed' and the new trace geometries are stored in the Traces, Depth Ticks, From/To and Point datasets.
  • The top-of-hole dip and azimuth values (at depth = 0) will use the values from the Survey feature class, if present.
  • If top-of-hole survey values are not present, the collar dip and azimuth values will be used instead (with the collar values taking precedence).

Related Topics

 

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