How can I increase the available memory for the application I want to use?
There are more than one possibilities to expand the available memory:
- To increase the memory of applications which are started by executables (like visat.exe or visat), edit the correspondig *.lax file and set the following entry to the memory size in bytes you want to provide to the application:
lax.nl.java.option.java.heap.size.max = 1073741824
- Some BEAM applications can also be started with a batch file (like visat.bat). In this case edit the batch file and increase the -Xmx value to the memory size you want to provide to the application.
For example the line
CALL "%JAVA_EXE%" -Xms64M -Xmx512M -classpath...
CALL "%JAVA_EXE%" -Xms64M -Xmx1024M -classpath...
- To increase the memory of applications which are started with a shell script (like visat.sh), edit the shell script and increase the -Xmx value to the memory size you want to provide to the application.
For example the line
$JAVA_EXE -Xms64M -Xmx512M
$JAVA_EXE -Xms64M -Xmx1024M
How does BEAM interpolate tie-point grids (e.g latitude) to resize them to the same dimension as the other bands?
Tie-point grids provide additional geophysical parameters in a data product on a sub-sampled grid. When accessing the values of a tie-point grid for a given pixel position (pixel center) defined in the product's scene raster, linear interpolation between tie-points is performed. If the pixel position is located outside of the region covered by the tie-points, extrapolation is applied. In order to correctly interpolate values crossing the 180° meridian the sine and cosine values of the longitude are used for interpolation.
MERIS Level 2b data products do have the unit of normalized reflectance is shown in BEAM with "dl", what is the definition of "dl"?
"dl" means *d*imension*l*ess in the Envisat terminology.
I want to use the output data of BEAM in MATLAB. But MATLAB only accepts the HDF4 format. What can I do?
Save your product to disk. This will convert Envisat Format to BEAM-DIMAP (default). BEAM-DIMAP uses flat, raw binary image files which you can read with MATLAB. Refer to the VISAT help for more information on the BEAM-DIMAP format.