4.2. 'General Settings' Tab Pane

'General Settings' Tab Pane

Figure 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
Drop-down menu for the selection of the area to apply the AE correction

Figure 4.3. Drop-down menu for the selection of the area to apply the AE correction


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].