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Purpose

 

In some cases - i.e. for Radarsat-1 data - it has been experienced that the original azimuth pixel spacing is not in agreement with the original Pulse Repetition Frequency. This problem, if not corrected, affects the geocoding.

 

A new value, corresponding to the corrected Pulse Repetition Frequency, is calculated. This will be used for further processing.

The original Pulse Repetition Frequency value, even if not used anymore, is not erased from the header file. The original Pulse Repetition Frequency can be possibly restored.

 

To execute this step a Ground Control Point file must be previously created.

 

Technical Note

This functionality can be used only for slant range products.

 

This step does not generated any relevant output file. The process consists of recomputing the Pulse Repetition Frequency and substitute the newly calculated value to that stored in the header file of the input data.

 

The Ground Control Point file must contain at least two points (their position will be entered both in the input SAR geometry and in cartographic co-ordinates), which are as much as possible separated in azimuth direction in order to optimize the Pulse Repetition Frequency value correction. It is important to note that only those points, which are labelled as "reference_gcp", are used in this process.

 

Input Files

 

Input file

Input file name of the data to correct. This file is mandatory.

 

Geometry GCP file

Either a previously created Ground Control Point file (.xml) is loaded (Load GCP File) or the interface to create a new Ground Control Point file is automatically loaded (Create GCP File, refer to the "Tools>Generate Ground Control Point" for details). This file is mandatory.

 

Parameters - Principal Parameters

 

Restore Original Value

The original Pulse Repetition Frequency value is restored.

 

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

 

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.

 

References

 

None.