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Purpose

 

The Ground Control Point file (xml or shape format), which can be required as input for processes such as Orbital Correction, Geocoding, Interferogram Flattening, Persistent Scatterers and others, is generated.

 

Technical Note

Please, for details on technical notes and use refer to the GCP Manual at https://www.sarmap.ch/tutorials/GCP_Manual_V_1_1.pdf

 

 

Input File(s)

 

 

 

Input file

The SAR image which the GCP (or GPS points) refers to. This file is mandatory.

 

DEM file

It is used to retrieve the height of those GCPs whose height ("Z") has not been entered. This file is optional.

 

Reference File

The geocoded SAR image which the GCP (or GPS points) refers to. This file is optional.

 

 

Input Parameter(s)

Name

GCP  name.

 

Map X

East-West cartographic co-ordinate of the selected pixel.

 

Map Y

North-South cartographic co-ordinate of the selected pixel.

 

Height

Elevation in meters (above the ellipsoid) of the selected pixel.

 

Image X

File co-ordinate, in the "Input file" geometry, of the selected pixel (x direction).

 

Image Y

File co-ordinate, in the "Input file" geometry, of the selected pixel (y direction).

 

Vel. X (mm/y)

Displacement velocity (mm/year) in East-West direction. This parameter is normally (not necessarily) entered only when the GCP file has to be used in the "Refinement and Re-flattening" processing step aimed at Displacement Mapping.

 

Vel Y (mm/y)

Displacement velocity (mm/year) in North-South direction. This parameter is normally (not necessarily) entered only when the GCP file has to be used in the "Refinement and Re-flattening" processing step aimed at Displacement Mapping.

 

Vel Height (mm/y)

Displacement velocity (mm/year) in vertical direction. This parameter is normally (not necessarily) entered only when the GCP file has to be used in the "Refinement and Re-flattening" processing step aimed at Displacement Mapping.

 

Date

The date (DD-MMM-YYYY; e.g. 12-JUL-2010) which the GCP position, and its displacement velocity, refers to. This parameter is optional, in case it is omitted the acquisition date of the "Input file" is used instead.

 

Cartographic System

In case that the Digital Elevation Model is not used, following parameters are compulsory:  

 

State

Definition of the country or general projection systems.

 

Projection

Definition of the projection system of the selected State. In case that a general projection system is selected in State, the Projection is automatically set.

 

Ellipsoid

Definition of the ellipsoid. This is chosen according to the selected State and Projection.

 

Hemisphere

Definition of the hemisphere. This is chosen according to the selected State and Projection.

 

Zone

Definition of the zone. This is chosen according to the selected State and Projection.

 

Datum Shift Parameters

Definition of the datum shift parameters. These are chosen according to the selected State and Projection.

 

Reference Height

In case that the Digital Elevation Model is not used, a constant ellipsoidal height must be provided. Default Reference Height is 0.

 

Cartographic Parameters

The reference parameters for some projection systems (e.g. Stereographic, Polar Stereographic, Gnomonic, Mercator, Miller, Albers, etc.) can be set.

 

Output(s)

 

Root name of the output file.

 

.xml

Ground Control Point file to use as input in any processing step where it is required.

 

.pts

ASCII file of the Ground Control Points.

 

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

 

General Functions

 

Start        

Start of the processing.

 

Store Batch        

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

 

Cancel        

The window will be closed.

 

Help        

Specific help document section.

 

 

Specific Function(s)

 

GCP Position

The file co-ordinates (Row and Column) corresponding to the cursor location are displayed.

 

Insert GCP

The file co-ordinates corresponding to the Ground Control Point position are stored.

 

Update GCP

If the parameters of a selected Ground Control Point are modified in the underneath table, the changes are saved by clicking this button.

 

Delete GCP

The selected Ground Control Point is deleted.

 

References

 

None.