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Purpose

 

The Quality of a Digital Elevation Model can be compared against existing reference products (e.g. Reference DEMs, GPS points, etc.).

 

The validation data are generated as .txt, .xls, .xml and .shp files.

 

Technical Note

A standard deviation based coregistration is carried out to estimate the shift between reference and input DEM.

This tool is intended for validating the quality of products where the maximum spatial shift between "Reference DEM file" and "DEM file" is in the order of a few pixels; in case of shift values larger than 40 pixels this tool has not to be used for validation purposes.

 

Input Files

 

DEM file

Input Digital Elevation Model to validate. This file is mandatory.

 

Input Reference file        

Digital Elevation Model to use as reference in the validation process. This file is mandatory if the "Shape File" (with Easting, Northing and Height values) is not provided.

 

Input Shape File        

This file must be in .shp format. It can made of points (each provided with Easting, Northing and Height values) or polygons. This file (made of points) is mandatory if the "Reference DEM File" is not available. If this file is entered, the validation statistics relevant to each point/polygon - and to any label/class of the shape - are also generated.

 

Optional Files

 

Mask File        

This is a classification-like input. This file is optional. If it is entered the validation statistics relevant to each input class are also generated.

 

Parameters - Principal Parameters

 

Shape Height Field Name

In case a "Shape File" of points is used, where the height values are in a field whose name is not "Height", the name of the field containing the height values must be provided.

 

Parameters - Global

 

It brings to the general section of the Preferences parameters. Any modified value will be used and stored for further processing sessions.

 

Parameters - Other Parameters

 

It brings to the general section of the Preferences parameters. Any modified value will be used and stored for further processing sessions.

 

Output File

 

Output Root Name

Name of the output root. This file is mandatory.

 

_raster_stat        

Overall validation statistics (.txt and .xls format). If the "Mask File" is entered, the validation results are also provided specifically to each input class.

 

_shape_stat        

Validation statistics (.shp, .xml, .txt and .xls format) related to the input "Shape File" . If the "Mask File" is entered, the validation results are also provided specifically to each input class.

 

Details specific to the Units of Measure and Nomenclature of the output products can be found in the Data Format section.

 

General Functions

 

Exec

The processing step is executed.

 

Store Batch        

The processing step is stored in the batch list. The Batch Browser button allows to load the batch processing list.

 

Close        

The window will be closed.

 

Help

Specific help document section.

 

 

Specific Function(s)

 

None.

 

See Also

 

Task, SARscapeBatch object, SARscapeBatch script example

 

References

 

None.