# Traverse

A traverse is a collection of points that belong together for some reason. Here are some examples:

• A parcel boundary, including tangents, curves and / or spirals.
• A road center line
• The topo shots that define a stock pile or rock
• Control points and side shots imported from a data collector
• Edge of Asphalt points recalled in sequence to draw the edge of a parking lot in a drawing
• A building foundation with two reference points at each corner for stakeout purposes
• All the conifer shots in a site survey (all drawn with a conifer point symbol and color)
There are as many different reasons to group points together as there are survey jobs.

## Traverse Point Sequence

Traverses are defined by the sequence of points. TPC displays a traverse's point sequence in the Traverse View stating with the first traverse point at the top.

Computations - traverse computations are based on the traverse point sequence. Changing the sequence may change the computed positions of the points.

Drawings - a traverse is represented in a drawing based on its point sequence. Changing the sequence may change the shape of the traverse in the drawing.

Breaklines - a surface creates breaklines from a traverse based its point sequence. Changing the sequence may change the breaklines.

There are other program functions that depend on a traverse's point sequence. So two traverses with the same 10 points in different sequences for example, are not the same traverse.

In the example shown here, the point sequence closes back on itself by repeating point '1' at the end. Also, the last two points define a curve as designated by the 'PC' and 'PT' point types.

If the Type column is blank, that point is a control point.

## Traverse Point Types

A traverse is also defined by its Point Types - like side shots, backsights, benchmarks, offsets, PI's and others.

In this example, we have a typical start to a total station traverse used in a site survey (gathering information).

• CS2 - the control point where the instrument is setup.
• CS9 - the backsight for the shots that follow
• CS10 - a sideshot to another control point (probably used to double check the setup before continuing on)
• 1-5 - side shots with descriptions.

This is very typical of how Point Types and Point Sequence combine to start a traverse.

Notice the status bar at the bottom of the Traverse View. When the Horiz Angle for sideshot 2 is selected, it indicates the backsight (BS), occupied point (OP) and foresight (FS) that the angle belongs to.

## Inverses vs Raw Data

The Traverse Views in the previous examples are displaying the computed inverses between the points. This is typical of how you use a Traverse View most of the time. As you enter the data for a point (Raw Data), TPC computes that point's position and the displayed inverse exactly matches the data you just entered. But what if you have done a traverse adjustment or rotated and translated parts of the survey? What happens to the raw data you entered then?

You can display the Raw Data any time by choosing View | Display Raw Data. Notice in this example that some of the cells are blank. Those are the cells without Raw Data. When you are not displaying raw data, these cells are filled in with inverses.

You can see by this example that the data you enter for each point in a traverse is retained with that point, even when you adjust the traverse or modify the survey. If you were to recompute this traverse, the raw data is available to recompute the points based on the Point Sequence and Point Types.

## Name vs Description

A traverse always has a name and may also have an optional description. Both can be entered in the Traverses Manager and the traverse properties dialog.

The traverse name must be unique while the description need not be unique. Another important difference between the two is that the traverse name is used by default when you label a traverse using the Traverse Settings. If the traverse name is Lot 2, the lot label starts out as Lot 2 (you can always edit it). If you are planning on labeling traverses in this manner, consider keeping the traverse name short and using the description for additional information used to identify a traverse.