STAR*NET V6 - Circe

Chapter 5 Preparing Input Data
When you add the optional “ANGLECALC” keyword to the “MAPMODE” inline
option, the program subtracts the back bearing and fore bearing at each traverse station to
calculate a “neutral” turned angle. This allows you to easily combine data from two or
more maps having different bases of bearing! The created angles will be used in the
adjustment, not the incompatible bearings.
When beginning a traverse, set the initial back bearing by entering a bearing or azimuth,
plus the backsight station name on the “TB” line.
The “MAPMODE” examples below illustrate data for open and closed traverses using
the optional “ANGLECALC” extension. As illustrated in the second example, closed
traverses are a special case. When a traverse closes on itself, the initial back bearing and
backsight station name may be omitted. The back bearing and backsight station name
will be automatically taken from the last “T” line data.
.MAP ON ANG
TB N10-00-00E 125 #Backsight station 125
T 101 N60-22-33E 543.21 #Angle of 50-22-33 is created
T 102 N73-30-55E 650.00 #Angle of 193-08-22 is created
T 103 N00-00-00E 533.25 #Angle of 73-30-55 is created
TE 104
TB #For closed traverses, the initial
T 501 N00-00-00E 100.00 #back bearing and station name may
T 502 N90-00-00E 200.00 #be omitted. The initial backsight
T 503 S00-00-00E 100.00 #in this example is assumed to be
T 504 N90-00-00W 200.00 #to station 504.
TE 501
.MAP OFF
In the open traverse above, if a bearing and station name are placed on the “TE” line as
illustrated below, the program will create a “closing” angle to the specified station, and
that angle will be included in the adjustment.
T 103 N00-00-00E 533.25
TE 104 N20-00-00W 105 #closing angle of 70 deg to 105 is created
Caution! If you are using this option along with the “.Measured Bearing” mode so that
bearings are interpreted as geodetic rather than grid, geodetic angles will be created just
as you would expect. But beware that there is no consideration for change in
convergence along the traverse line! This is only a data preparation tool which creates
angles while reading input data. The program simply subtracts the adjacent bearings to
get an angle, much like you would do by hand.
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