Point Comparison by AlignmentPoint Comparison by Alignment

(Not available in LISCAD Lite)

Generates a report by selecting an alignment, offsets and a model. The points within the offsets are compared to the model elevations and reported by chainage with respect to the section markers.

To allow easy separation of "as constructed" survey data from design, the points, alignments and models utilised in these reports can optionally reside in different SEE files.

This operation is group sensitive and block sensitive.

The Report/Point Comparison/by Alignment command is selected from the Plan View Utilities task.

Compare Points by Alignment dialog box

Item Used to
Points Project Display the name of the currently open project, which contains the points to be reported.
Reference Project Display the name of the reference project, from which the "Alignment" will be selected.
Browse Open the Browse dialog box to select the Reference Project, from which the "Alignment" will be selected.
Alignment Select a "Reference Alignment" from the available list. The Chainage and Offset will be computed for each point, with respect to this alignment..
Start Chainage or Start Distance Enter or select the alignment starting chainage or distance of the report.
The name of this field is dependent on what has been set as the Data Input By type in the Configure/Alignment dialog.
End Chainage or End Distance Enter or select the alignment end chainage or distance of the report.
The name of this field is dependent on what has been set as the Data Input By type in the Configure/Alignment dialog.
Offset 1 and Offset 2 Enter the offset values that define a corridor within which points will be used in the report. The offsets may be left (negative) or right (positive) of the alignment.
Distance Range (+/-) Enter a distance range to search either side of the section markers.
Model Elevation Shift Enter a value to shift all model elevations. The value entered will be added to the model elevations used.
Output Extended Header Select whether header information is to be in the report.
Header information includes the details of the current data base at the head of the report. These details may also be viewed or edited in the Utilities/Edit/Details command.
Insert Blank Row Between Sections If selected a blank row will be left between each group of points relating to the section marker.
Insert Section Labels If selected the section chainage and distance will be inserted between each group of points relating to the section marker.
Include Points Outside Distance Range If selected all points within the search criteria will be reported on against the nearest section marker. In this case the distance range will be used to optionally flag any points that are greater than the distance range from a section marker.
Model Surface
Data Set: Display the name of the database that contains the model that is to be used in the comparison.
Browse Select a database from which a model is to be used in the comparison. This may be the currently open database or any other SEE database. Displays the Browse dialog box for selecting the data set.
Model Name: Select the model that is to be used in the comparison.
Format
Position Select which attributes are to be output.
Using the arrow up/down keys to increase or decrease the column number can set the column position of each attribute type.
The column numbers increase from left to right. Set the Position to 0 (zero) to remove the attribute type in the report.
Outside Distance Range This field displays an * against any points that are outside the distance range entered. This will only report if "Include Points Outside Distance Range" is selected.
Elevation Difference The elevation difference between the elevation of the point and the interpolated model elevation (plus shift if applicable) at the same co-ordinates.
Out of Tolerance In the report, any height differences that are above or below the tolerances set will be indicated by a '*' character in the report. The Upper and Lower Tolerance fields will only be relevant if this option is selected to be output to the report.
Upper Tolerance Key in the upper tolerance of the elevation difference to be used.
Lower Tolerance Key in the lower tolerance of the elevation difference to be used.
OK Perform the comparison operation and produce the comparison report.
The operation may take a considerable period of time to complete, particularly for large data sets.
Cancel Close the dialog box.

Summary in Report

Total Points in Project: The total number of points in the project.
Points within offset range: The number of points within the offset range.
Number of points outside model: The number of points selected within the range, but not in the model area.
Minimum elevation difference: The highest value that a point is above the model.
Maximum elevation difference: The lowest value that a point is below the model.
Points Processed: The number of points processed.
Points Beyond Distance Range (Longitudinal): The number of points ignored that were outside the selected distance range.
Number of points above tolerance: The number of points above the tolerance set.
Number of points below tolerance: The number of points below the tolerance set.
Upper tolerance: The upper tolerance set.
Lower tolerance: The lower tolerance set.
Percentage in tolerance: The percentage of points that were within tolerance.
Percentage below tolerance: The percentage of points below tolerance.
Percentage above tolerance: The percentage of points above tolerance.
Mean elevation difference: The average of all elevation differences.
Mean error: The average of all absolute elevation differences.
Standard deviation: The standard deviation of the differences. The standard deviation is computed using the difference between the actual elevation of each point and the elevation interpolated for that point using the model surface. All points within the requested chainage/offset range from the alignment that have an elevation set are used in the calculation of the standard deviation.