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Purpose

 

It allows subtracting or adding the geoid related height from (or to) an input Digital Elevation Model.

 

Technical Note

In any SARscape processing where the DEM input is foreseen, ellipsoidal heights have to be preferred in order to avoid errors related to the use of geoids, which differ depending on the specific geographic location; vice versa the adoption of ellipsoidal heights ensure consistency with most of the current satellite systems, whose measurements and parameters are referred to earth center.

 

This tool provides the possibility to subtract the geoid component to a previously imported Digital Elevation Model, before it is actually inputted in any SARscape processing step.

 

On the other side, if the objective is to get the real geoidal height, this same tool allows adding the geoid component to a previously generated Digital Elevation Model referred to the ellipsoid.

 

It is important to mention the this tools allows adding or subtracting the WGS 84 Earth Gravitational Model 96 (EGM96) geoid as well as the WGS 84 Earth Gravitational Model 2008 (EGM2008).

 

Input Files

 

Input file

Input Digital Elevation Model to be processed. This file is mandatory.

 

Parameters - Principal Parameters

 

Geoid Operation

Substract Geoid

The selected geoid component is subtracted to the input Digital Elevation Model.

 

Add Geoid

The selected geoid component is added to the input Digital Elevation Model.

 

Geoid

EGM96

Earth Gravitational Model 96.

 

EGM2008

Earth Gravitational Model 2008.

 

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 Files

 

Output file

Output Digital Elevation Model with the geoid component added or subtracted. This file is mandatory.

 

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

 

Pavlis, N.K., S.A. Holmes, S.C. Kenyon, and J.K. Factor, An Earth Gravitational Model to Degree 2160: EGM2008, presented at the 2008 General Assembly of the European Geosciences Union, Vienna, Austria, April 13-18, 2008.