STAR*NET V6 - Circe

6.5 Preanalysis
Chapter 6 Running Adjustments
When you choose Run>Preanalysis, STAR*NET processes the network using a list of
approximate coordinates for all stations supplied by you, and a list of observation codes
to indicate which distances, angles, and other field data will be observed. No actual field
observation data is required. STAR*NET will analyze the geometric strength of the
network using your approximate layout and the instrument accuracies supplied as
observation standard errors. The predicted accuracy of each station will be computed,
and error ellipses generated.
# Approximate coordinates for proposed survey
#
C 1 51002 101009 ! !
C 2 51005 101343
C 3 51328 101291
C 4 51416 101073
#
# Proposed Observations
#
4
D 1-2
D 2-3
ANGLE
D 3-4
D 4-1
D 1-3
A 2-1-3
A 3-2-4
A 4-3-1
A 1-4-2
A
#
1-4-3
# Fixed Bearing
#
ANG
B 1-2 ? !
1
D IS TA N C E
Sample Preanalysis Data
The example above shows a very small Preanalysis data file. It is important to note that
approximate coordinates are required for all stations, to indicate roughly where survey
points are planned. The distance and angle lines show which observations are planned.
Observation standard errors default to the global values for each data type. If an explicit
standard deviation is required, for example to fix a bearing as shown in the sample data
above, use the “?” character as a place holder for the unknown data. An example in
Appendix-A, the STAR*NET Tour, provides another, somewhat larger, sample
Preanalysis data set.
106
ANGLE
D IS TA N C E
D IS T A N C E
B E A R IN G
D IS TA N C E
ANGLE
ANGLE
3
D ISTA N C E
2