5. Summary

This example looked at a few different SPC grid reduction methods. Depending on the accuracy needs of the survey, simple methods may be sufficient instead of more complicated (and time consuming) ones. The decision should be based on examination of worse-case scenarios.

If the two lines of the example survey represent the extreme situations, we determined that

  • distance reduction - Jerry's grid scale could be used for the entire project but each line should use its own average elevation
  • arc-to-chord correction - was not significant enough to affect directions or angles.