Entering Redundant Data

Least Squares allows you take extra (redundant) observations which it uses to strengthen the network. A redundant observation can be an extra angle you turn between two points or a distance you measure between two control points that weren’t traversed sequentially. A redundant observation can also be created when you shoot the distance to your backsight when turning an angle set.

Degrees of Freedom

Redundant observations are often referred to as ‘Degrees of Freedom’. This term is used in most Statistics texts and is often carried over into Least Squares analysis.

Entering Redundant Data

  1. In the Traverse View, enter data to a protected OP, FS or SS point. Since the protected point can’t be recomputed, TPC assume you just want to enter redundant data.
  2. In the Traverse View, recall an existing point and choose the ‘Recall existing point as redundant observation’ option from the dialog box. If you have already entered raw data for the point in the Traverse View, TPC will retain the raw data you entered as redundant data. TPC will display OBS in the Type column.
  3. In the Traverse View, recall an existing, unprotected point and enter raw data for it. On the first raw data value you enter, you will be prompted to save the raw data. Choose yes. TPC will display a dialog box giving you the options to inverse all the raw data and / or make it a redundant observation.
  4. In the Traverse View, turn on Obs=Observation in the Type menu for a SS, OP or FS. TPC displays OBS as the point type.
  5. In the Traverse View, create a unique FS or SS but put the Least Squares redundant character in the description along with the redundant point label (i.e. =100 or #100). Although TPC computes the coordinates of the unique point it will create a redundant record to the redundant point for the least squares analysis. If you plan on using the Closure View to check the area or closure of this traverse, you must use this method as TPC needs a unique closing point for those computations.

Reporting Redundant Observations

The Least Squares report includes the word ‘Redundant’ next to any redundant observation.

Editions

Premium, Professional

Related Topics

Traverse View
Entering Traverse Data
Adding Data to an Existing Traverse
Displaying Raw Data