Design & Adjustment

To perform a network design simulation (also known as Pre-Analysis), a data set is required. This data set includes estimated coordinate positions for each proposed station (usually scaled from a map) and the observation types which are to be measured, along with their expected errors, expressed as standard deviations.

COLUMBUS can simultaneously analyze this data and let you know if the resulting network will statistically meet your requirements. If not, COLUMBUS lets you easily alter the model, by adding or removing stations or observations, or by changing the expected error for each observation.

1D Vertical Networks

• Can be constructed using traditional leveling observations.

• Can be weighted by the standard deviation for each observation, by the distance between stations or by the number of setups between stations.

• Valid observation types include: Height (or Elevation) Differences, Local Delta Up and/or a Height Coordinate.

2D Networks

• Often useful when no vertical observation component exists or you did not measure your instrument/target heights.

• Adjusted in true 3D space at an average selected project height.

• Similar to the 3D adjustment, except all stations are held fixed (1D) at the same height.

• Valid observation types include: Azimuths, Bearings, Directions, Horizontal Angles, Zenith Angles, Chord Distances, Horizontal Distances, Geodesic Distances, Geodesic Chord Distances, Local Delta North and Delta East, and Latitude/Longitude Coordinates.

COLUMBUS also allows for historical observations from plats to be used in this type of adjustment.

3D Networks

• The most commonly used model.

• Any type of observation supported by COLUMBUS can be used.

• Stations can be fixed in either 1D, 2D or 3D.

• Any component for a station can be constrained to move within a limited area.

• Valid observation types include: Azimuths, Bearings, Directions, Horizontal Angles, Zenith Angles, Chord Distances, Horizontal Distances, Geodesic Distances, Geodesic Chord Distances, Height Differences, and Local Delta North, East and Up, GPS Delta X, Y and Z, plus Latitude/Longitude/Height Coordinates.