Flight/Tie Differences (Batch QC Parameters)

Use the Flight/Tie differences tab (QCINTERSECT GX) to carry out quality control on data values measured at the intersection of flight and tie lines.

Flight/Tie Differences tab options

Data channel	Select the data channel to use to determine the differences. This could be, for example, a radar altimeter channel to QC altitudes. This is a required field. Script Parameter: QCINTERSECT.CHAN
Maximum difference	Specify the maximum difference. This could, for example, mark the locations where the altitude at the intersection points differ by more than this specified amount. This is a required field. Script Parameter: QCINTERSECT.ALLDEV

Application Notes

Current database

This GX assumes that the current database is the one containing the actual survey data. The database is called the survey database. If you wish to process a different database, you may browse to add it to the project or select one from the workspace list.

Quality Control Specification and Indicators

This dialog first determines the intersection points between flight lines (e.g. L100) and tie lines (e.g. T50) in a database. The difference between the data values recorded in the input channel at the intersection points are written to a new channel in the database: IntDiff, at the rows whose fiducial is the closest to the actual intersection.

The dialog then creates a Flag_Int channel. This channel contains a value of 1.0 anywhere the difference in the intersection value is outside the specification. All other points, both intersection and non-intersection, are given a value of 0.0.

The out-of-specification points are written as circular blue symbols to the map. Because the discretely recorded data points are not necessarily exactly at the intersect points, the symbols themselves may not be plotted exactly at the intersections points, but at the point on the flight line closest to the intersection.