Global Mapper can copy attributes to features from overlapping or nearby features. This is similar to a spatial join, where the attribute table of one set of features gets updated based on the spatial relationship to another set of features.
When features are loaded, the Attribute/ Style Functions sub-menu of the Digitizer menu will contain an option to Copy Attributes Between Overlapping/ Nearby Features. To use a subset of loaded features, before a selection before choosing this option.
Selecting this option will display a dialog to copy attributes from features to other features(i.e. loaded or selected areas, lines or points).
Copy Attributes From— specify the features that contain attributes that will be copied. This may be all features or selected features based on the geometry type (points, lines, areas).
Copy Attributes To — Specify the features to gain the new attributes based on the spatial relationship to the features specified above.
Attributes to Copy
Select the names of the attributes that will be copied. Use the Check All and Uncheck All buttons to quickly clear or select the full list.
Multiple Feature Handling
This section will be enabled when multiple features in the Copy Attributes From selection may match features in the Copy Attributes To section. This is based on the geometry type, for example an area may contain many points, so copying from point features to area features will require a Multiple Feature Handling setting.
Keep Attributes Value from Each Matching "From" Feature
The attributes values from each matching "from" feature will be copied to the "to" attributes as a comma separated list.
Don't Add Any Attributes if Multiple Matching Features
If multiple from features are found, no attributes will be copied to the to features.
Keep Attributes from First/ Closest Matching Feature
If multiple from features are found, attributes for the closest matching "from" feature will be copied to the "to" feature.
Keep Minimum Attribute Value from Matching "From" Features
The lowest value will be copied to the feature.
Keep Maximum Attribute Value from Matching "From" Features
The highest matching value will be copied to the feature.
Create Copy of "To" Feature for Each Matching "From" Feature
When copying attributes from point feature to area features, this setting will create multiple (duplicate) area features with different attributes for each "from" point.