Extract data from an existing coverage to create a new coverage using a geometry to define the boundary for the extraction. The geometry can be in the form of area features on a feature layer, a selection of area features, a geometry file in WKT format or a WKT string of coordinates.
Interface
To extract a coverage by geometry, the following dialog box is used.
Set bands to be filtered, use Filter Expressions and set type of geometry to use as filter.
Option | Description |
|---|---|
Data Source | The coverage to use as the data source for the extraction. The drop-down list will be populated with all coverages open in the application at the time the dial og box was launched. If a coverage was active at the time, that coverage will be selected as the source by default |
Filter | |
Bands | The bands to inc lude in the output coverage. 1. Click the check box to sele ct each band to be included |
Expression | Optionally apply a filter to the coverage data being extracted. Only data that meets the filter criteria and the specified geometry will be extracted. The filter is specified in the form of a mathematical expression. The expression can be typed manually or the browse button (...) can be used to launch the Expression Builder dialog box, which provides an interface to create the filter expression. The red X button can be used to clear the current expression if needed. A confirmation message will be displayed if this button is clicked. |
Include rejected points | Enable this option to include rejected points in the output coverage. |
Boundary Input | |
Existing Geometry | Define the boundary for the extraction using area features open in the application. The geometry can include all area features on a feature layer open in the application, or it can be limited to the features in a selection or a superselected feature. The drop-down list is populated with all feature layers in a supported format, as well as <Selection> and <Superselection> if area features were selected when the dialog box was opened |
Geometry file | Define the boundary for the extraction using a WKT file containing the coordinates of the area to be included. |
New Geometry | Manually define the boundary for the extraction either by: • typing or pasting coordinates of the inclusion area in the WKT string box, or • clicking the Current Extent s button to populate the WKT string box with the coordinates of the current extents of the 2D View. The red X button can be used to clear the current string if needed. A confirmation message will be displayed if this button is clicked. 1. Click the button to enable the New geometry option. 2. Populate the WKT string box. |
Exact Data | The type of extraction to be performed. • Within the boundary will extract only data that is within the specified geometry boundary. • Outside the boundary will extract only data that is outside the specified geometry boundary. |
Output file name | Select or create a location to create the file in. |