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This dialog displays the estimates of standard error for either the survey or for an individual traverse.
Distance - Horizontal and Vertical
Horizontal and vertical distances are specified both as a constant and a part per million (PPM). Distance precisions for each observation are computed as the constant value plus the PPM value multiplied by the distance measured.
Constant Horizontal
TPC combines instrument centering and target centering standard errors in the Constant Horizontal standard error.
Constant Vertical
TPC combines instrument height and target height standard errors in the Constant Vertical standard error.
All distance standard errors are in survey units.
Angles - Horizontal and Vertical
Specifies the standard error of an angle measurement in seconds.
Pointing = this is a reflection of your sighting of the target. If you do not sight exactly at the center of the target, or do not sight the exact same spot on the target when turning angle sets, you will get this error.
Reading = provided by the manufacturer of your instrument. This is a reflection of the instruments precision.
As a rule, you can think of TPC as combining these two errors to get a total error for the angle, but TPC may also do additional computations based on each individually.
All angle standard errors are in seconds.
Vertical Angle
Specifies the standard error of a vertical angle measurement in seconds. TPC uses both Vertical (horizontal = 0 degrees) and Zenith (horizontal = 90 degrees) and both use the same Vertical Angle standard error shown here.
Direction - Azimuth/Bearing
Specifies the standard error of an azimuth or bearing measurement.
Coordinates
Standard errors for coordinates allow you to use RTK computed values at varying distances from their base / reference stations.
The value you enter here will account for an centering error and ppm based on an average distance from the base / reference station.
All coordinate standard errors are in survey units.
Fix
TPC uses an estimate of -1.0 to identify fixed coordinates. Press the button to set the coordinate estimates to -1.0.
Free
TPC uses an estimate of 0.0 to identify coordinates which are not weighted. Press the button to set the coordinate estimates to 0.0.
Save as Defaults / Recall Defaults
Choose these options to save and recall the default APriori values. When you start a new Least Squares analysis, TPC uses the default values.
Once a Least Squares analysis is performed, it stores its APriori values in the .LSA file. The next time you access that analysis, you will see the APriori values stored with the analysis, not the default values you have saved here.
Remove Traverse Estimates
Remove any estimates from this traverse and exit the dialog. The traverse will no longer contribute its own standard error estimates to the least squares analysis. Instead, observations generated by this traverse will use the standard error estimates of the least squares analysis.
This button is displayed when this dialog is accessed from within a Traverse View or the Traverses Manager.
OK
Accept the values and exit.
Cancel
Exit without accepting the values in the dialog.
Related Topics
Least Squares
Editions
Premium, Professional
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