STAR*NET V6 - Circe

The “TB” Code: Beginning a Traverse
Chapter 5 Preparing Input Data
Begin a traverse by entering either a backsight station name, or a fixed backsight bearing
or azimuth. When you enter a bearing or azimuth, always enter it in a direction away
from the first traverse station. An optional “Traverse Description” will display as a
traverse description in the “Traverse Closures” section of the listing.
TB BS Station Name [Traverse Description]
TB BS Bearing (or Azimuth) [Traverse Description]
Example 1:
TB 25 ‘Smith Ranch Road to South Creek
In this example, we begin the traverse by backsighting to station “25”, another station in
the network. A description is entered to identify the traverse in the output listing.
Example 2:
TB S30-42-15W ‘South Creek to Leland
Here we begin the traverse by entering a backsight along a fixed bearing rather than to
another station in the network. An optional traverse description is entered.
Internally, STAR*NET generates a dummy backsight station for each data line of this
type, beginning with DUMMY0001. The dummy station is located at an arbitrary
distance of 1000 units (feet, meters, etc.) from the first traverse point along the backsight
bearing or azimuth. You will see these stations in the angle observation summary, but
they do not appear in the plot files or the output coordinate file. You cannot use these
dummy stations for any purpose in your data.
In the “TB” line, the data item is either a station name, or a bearing (or azimuth) value. If
the item contains dashes and can also be interpreted as a valid bearing or azimuth, then it
is used as such. Otherwise, it will be used as a station name.
When you enter a bearing or azimuth using “packed” DMS format or GONS, you must
prefix the entry with the characters “B=“ or “b=“ so that STAR*NET will not interpret it
as a station name. Examples: B=S30.4215W or B=44.1135.
It is generally preferable to backsight to an “actual” station in the network as shown in
the first example rather than having STAR*NET create a “dummy” station at a given
bearing but an arbitrary distance away. You can easily create your own backsight station
using one of several data types – by using the “BM” data line for example.
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