.. _SARDecompositions: 

SARDecompositions
=================





From one-band complex images (each one related to an element of the Sinclair matrix), returns the selected decomposition.

Description
-----------

From one-band complex images (HH, HV, VH, VV), returns the selected decomposition.
 
All the decompositions implemented are intended for the mono-static case (transmitter and receiver are co-located).
There are two kinds of decomposition: coherent ones and incoherent ones.
In the coherent case, only the Pauli decomposition is available.
In the incoherent case, there the decompositions available: Huynen, Barnes, and H-alpha-A.
User must provide three one-band complex images HH, HV or VH, and VV (mono-static case <=> HV = VH).
Incoherent decompositions consist in averaging 3x3 complex coherency/covariance matrices; the user must provide the size of the averaging window, thanks to the parameter inco.kernelsize.



Parameters
----------

.. contents:: :local:

.. |br| raw:: html

   <br />

.. |em| raw:: html

   &emsp;

**Input Image** :code:`-inhh image` *Mandatory* |br|
Input image (HH)

**Input Image** :code:`-inhv image` |br|
Input image (HV)

**Input Image** :code:`-invh image` |br|
Input image (VH)

**Input Image** :code:`-invv image` *Mandatory* |br|
Input image (VV)

**Output Image** :code:`-out image [dtype]` *Mandatory* |br|
Output image

**Decompositions** :code:`-decomp [haa|barnes|huynen|pauli]` *Default value: haa* |br|


* **H-alpha-A incoherent decomposition** |br| H-alpha-A incoherent decomposition

* **Barnes incoherent decomposition** |br| Barnes incoherent decomposition

* **Huynen incoherent decomposition** |br| Huynen incoherent decomposition

* **Pauli coherent decomposition** |br| Pauli coherent decomposition



Incoherent decompositions
^^^^^^^^^^^^^^^^^^^^^^^^^



This group allows setting parameters related to the incoherent decompositions.

**Kernel size for spatial incoherent averaging** :code:`-inco.kernelsize int` *Default value: 3* |br|
Minute (0-59)



------------

**Available RAM (MB)** :code:`-ram int` *Default value: 256* |br|
Available memory for processing (in MB).



Examples
--------

From the command-line:

.. code-block:: bash

    otbcli_SARDecompositions -inhh HH.tif -invh VH.tif -invv VV.tif -decomp haa -out HaA.tif


From Python:

.. code-block:: python

	import otbApplication

	app = otbApplication.Registry.CreateApplication("SARDecompositions")

	app.SetParameterString("inhh", "HH.tif")
	app.SetParameterString("invh", "VH.tif")
	app.SetParameterString("invv", "VV.tif")
	app.SetParameterString("decomp","haa")
	app.SetParameterString("out", "HaA.tif")

	app.ExecuteAndWriteOutput()



Limitations
-----------

Some decompositions output real images, while this application outputs complex images for general purpose.
Users should pay attention to extract the real part of the results provided by this application.


See also
--------

| :ref:`SARPolarMatrixConvert`, :ref:`SARPolarSynth`