4.2. 'General Settings' Tab Pane
This tab pane (
Figure 4.2) consists of three
subpanels.
4.2.1. 'Processing' Subpanel
-
'Where to apply the AE algorithm': This drop-down menu provides the following options where the
AE algorithm shall be applied
(see alsoFigure 4.3):
-
Coastal regions over the ocean
-
Everywhere over the ocean
-
Coastal regions over ocean and land
-
Everywhere
4.2.2. 'Aerosol Type Determination' Subpanel
-
'Reference wavelength (nm)': A text field to enter the reference wavelength for Angstrom and
AOT values below. The default is 550nm..
-
'Angstrom': A text field to enter the Angstrom coefficient. The default is -1, the valid
interval is [-2.1, -0.4].
-
'AOT': A text field to enter the aerosol optical thickness. The default is 0.2, the valid
interval is [0.0, 1.5].
-
'Over water, compute aerosol type by AE algorithm': If this checkbox is selected,
the aerosol type over water used for the AE correction will be determined by the algorithm itself.
Otherwise, it will be taken from the Angstrom/AOT combination as set by the user above
(same as over land).
4.2.3. 'Advanced Options' Subpanel
-
'Perform convolution with OpenCL (for unique aerosol type only, GPU hardware required)':
If this checkbox is selected, the convolution (the core mathemaical part of the AE correction)
is performed using OpenCL libraries. Under suitable conditions, this results in a significant
speed-up
of the processor. However, this option is based on a rather new technology, and the implementation
in
ICOL+
is still somewhat experimental. There are the following limitations:
-
Suitable GPU hardware must be integrated in the computer and properly be installed.
In general, this procedure is machine- and platform-dependent and is completely separate
from
the
ICOL+ installation.
-
The current implementation is applicable only for an aerosol type which is unique (constant)
over the computed scene.
-
The efficiency of the procedure depends on the dimensions of the particular scene and is
parameter-dependent. Currently, a set of constant, hard-coded parameters is being used
which is very likely not perfect for many cases.
A more detailed description of the OpenCL issue is beyond the scope of this manual. A good
literature
starting point is e.g. [RD-4].