STAR*NET V6 - Circe

Chapter 5 Preparing Input Data
Zenith angles observed in the “inverted” position (those in the 270 degree range) may be
entered, and their inverted values will be properly handled. For example, a zenith angle
entered as 275-30-00 will be handled in the program as if it were 84-30-00, but it will
appear in the data and adjustment listings in its original inverted form so that listings can
be easily compared to original fieldbook information.
As you will see in the next section “Description of Data Format and Content”, some data
lines are for entering single observations such an angle or a distance, and others are for
entering multiple observations such as an angle, a distance and perhaps a zenith angle.
Whether data is entered with single or multiple observation lines, adjustment results will
be the same as long as the observations are the same.
The main advantage in using multiple observation data lines is that data preparation is
easier. For example, the name string (At-From-To) and any HI/HT data are entered only
once, but relate to all the observations on the line. Also, for 3D data, a very significant
advantage to entering the slope distance and zenith angle measurements on the same line
of data is that these observations can be automatically reduced to horizontal by
STAR*NET if you decide to process the data using a 2D adjustment.
Standard Errors
A “standard error” is a value used to weight an observation. When you enter standard
error values on a data line, they always directly follow the group of observations, one
standard error value for each observation. A standard error may be entered as a numeric
value or as a special symbol. The following table explains the various entries.
Entry Explanation
Numeric Value An actual Standard Error value (i.e. 0.03)
Nothing Entered Defaults to the value defined in the instrument options
The “&” Symbol Defaults to the value defined in the instrument options
The “!” Symbol The observation is FIXED
The “*” Symbol The observation is FREE
Standard Error Symbols
Many examples of entering explicit standard errors are shown in the next section
“Description of Data Format and Content”, but in practice you will likely do this only in
special cases. The normal procedure is to enter nothing so that the default instrument
settings in the Project Options are assigned. Or, if the “Instrument Library” facility is
used, the defaults for a particular weighting scheme are assigned.
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