Adjustment Summary Dialog

GeoLab’s Adjustment Summary Dialog is a useful tool used to analyze the results of an adjustment and aid in the removal of potential blunders and bad observations from the adjustment process.

There are three main components to the adjustment summary:

AdjustmentSummary.PNG

  • Station Confidence Regions: Flagged error ellipses corresponding to station accuracy data.

  • Relative Confidence Regions: Flagged error ellipses corresponding to observation accuracy data.

  • Standardized Residuals: Flagged observation quantities

    • These are flagged and ordered primarily based on their Standardized Residual value, which compares their residual against their standard deviation.

All flagged confidence regions and observations are shown in a box. For observations, their standardized residual value is shown; for confidence regions, their semi-major axis is shown in meters.

The remaining boxes on this dialog are populated when a quantity is selected (clicked):

  • At: at-station (if relevant)

  • From: from-station

  • To: to-station

  • Line: spatial distance of line, in meters

  • PPM: spatial error in parts per million (mm per km)

  • Resid: residual magnitude in meters (arc-seconds for angular observations)

  • Std: standard deviation value in meters (arc-seconds for angular observations)

Double-click on any of the flagged quantities in the adjustment summary to automatically scroll to the corresponding observation in GeoLab’s Listing file.

The Variance Factor box displays the final variance factor of the adjustment, which is a factor of the residuals will ideally equal 1.0. In addition, a statistical test (default of Chi-square) is applied to the variance factor to determine whether it is statistically acceptable.

The Listing File box displays the filepath of the corresponding adjustment Listing File.

The Comment out Selected Observation button is an exciting new feature that will automatically comment out whatever observation is selected in the observations (Standardized Residuals) box, in its appropriate input file.

You can control which confidence regions and observations are flagged using the appropriate controls in the Project Options dialog.

Mitch Palmer