Create macro / For repeated passes
Create macro / For repeated passes command creates a TerraScan macro automatically. The macro is used to classify points collected from the same location in several strips.
Especially in MLS data sets of roads inside urban areas, there might be places where data was collected several times during a survey. The command can be used to identify such locations based on trajectory position attributes. The process can make use of accuracy values that are assigned to trajectory positions. See Import accuracy files for more information. If the search finds repeated pass locations, the resulting macro contains steps that classify points based on time intervals.
To create a macro for repeated passes:
1. Select Create macro / For repeated passes command from the Tools pulldown menu.
This opens the Macro for Repeated Passes dialog:
2. Define settings and click OK.
The software computes time ranges of repeated passes from the trajectory positions and creates a TerraScan macro. An information dialog shows the number of added time intervals.
The macro can be saved and applied to the laser points. See Chapter Macros for more information about macros in TerraScan.
SETTING |
EFFECT |
|---|---|
From class |
Point class(es) from which to classify points. The list contains the active point classes in TerraScan. |
To class |
Target class for points collected in repeated passes. The list contains the active point classes in TerraScan. |
Keep pass |
Defines which data is kept in the original class: •First - data of the first pass. •Last - data of the last pass. •Best xyz - data of any pass with the best positional accuracy. •Best hrp - data of any pass with the best attitude accuracy. |
Minimum interval |
Minimum time interval within which the software searches for repeated pass points. |
Buffer |
Number of seconds that is added to each repeated pass time interval. The seconds are added at the beginning and in the end of a time interval. |
Xyz within |
Defines the maximum distance between repeated passes. If passes are less than the given distance apart from each other, they are considered repeated passes. |
Heading within |
Defines the maximum angular difference between repeated passes. If the heading angle between passes is smaller than the given value, they are considered as repeated passes. |
