The computation mode of COLUMBUS is changed by altering the current view (selected from the View menu). There are 10 view modes in COLUMBUS: 1D Vertical, 2D Geodetic, 3D Geodetic, Cartesian XYZ, State Plane (2D), State Plane (3D), UTM (2D), UTM (3D), Local NE (2D) and Local NEE (3D).

Example One: You have just entered several stations having State Plane coordinates and some others having geodetic coordinates.

To compute State Plane coordinates from the geodetic stations, you must first change the view to either 2D Geodetic or 3D Geodetic.
To compute geodetic coordinates from the State Plane stations, you must first change the view to State Plane (2D) or State Plane (3D).

Example Two: You have just loaded a COLUMBUS-compatible input file containing both terrestrial and GPS observations. You wish to perform a 2D geodetic network adjustment (at an average project height) utilizing the terrestrial observations. To do this you must first change the view to 2D Geodetic, then proceed with the network adjustment process. Setting the view to 2D Geodetic tells COLUMBUS the context of what is to follow (in this case, the 2D geodetic network adjustment).

Example Three: You have just entered several stations with Local NEE (north, east, elevation) coordinates, and you want to compute an area of a polygon bounded by these stations. You must first change the view to Local NE (2D) or Local NEE (3D) before defining the polygon and computing its area.

Hint: When setting the view context, ask yourself what coordinate system you want to compute from. That coordinate system should be selected as the view context.

Coordinates with Lat (or North) and Lon (or East) components of ZERO

When establishing a network, there are times when stations will have 2D coordinates of 0.0 (east-west and north-south). For example, you set up all your stations, but defined explicit coordinates for the control stations only. To insure the stations with 2D coordinates of 0.0 do not appear in the view as stacked on top of one another, COLUMBUS displays these stations as a spiral.

Vertical (1D) networks which have no 2D component are also displayed as a spiral. This way you can see all the relationships between stations (via connected observations) and also easily navigate to specific areas of the network topology.

To more easily spot stations with Zeros for coordinates, you can assign those stations a unique color. To do this, from the Options menu simply select Colors | Station Names with Coords of Zero, and then select a color.

Examining stations, observations and adjustment data using the View

The View is a powerful place from which to access station and observation data within COLUMBUS and adjustment/pre-analysis results.

To bring up coordinate information about a station, from the main View double-click on a station symbol. The coordinate type displayed (geodetic, cartesian xyz, state plane (2D), and so on) is dependent on the current view context; for example, 1D Vertical, 2D Geodetic, 3D Geodetic, State Plane (2D), and so on.
To bring up observation data, from the main View double-click on an observation line between two stations. If more than one observation set type exists between the two stations, you will be prompted for the observation set you wish to highlight view.
After performing an adjustment/pre-analysis, from the Results menu select Adjusted Network View. From here you can double-click on a station symbol to display its adjusted coordinates, double-click on an observation line to view the adjusted observation results, or double-click on an error ellipse to view the error ellipse results for a station or the relative error ellipse between stations.

Hiding stations within the View

Occasionally you may find yourself working with a network of data which is very dense. When this happens, the view of that data often gets very crowded and visually busy. To remove extraneous detail from the view, including stations and attached observations, you can selectively hide stations.

To hide stations and their attached observations, do the following:

From the View menu, select Hide Station(s).
Click on the names of the stations you wish to hide.
Click OK. The selected stations and connected observations will be removed from the view.

Note: These stations and observations are still available for use in network adjustments, network pre-analysis, cogo, and so on; they have only been removed from the view.

To return any stations (and their observations) to the view, simply return to the Hide Station(s) dialog box and deselect the applicable stations. Click OK to redraw the view.

Hiding stations is often helpful when attempting to zoom into a congested network. Remember to Hide any stations before you begin to zoom into an area.

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Network Adjustment and Coordinate Transformation
Software Solutions • Since 1990