Last update: February 2009
1 - Data Export: GEOTIFF format
The GeoTIFF format is a variation of the TIFF format, which additionally conveys geographic information. This geographic information is picked up from the header of the data. It is important to underline that the size of image does not change when doing a TIFF or BIL format export, that is the image is flipped with respect to the SAR geometry. No rotation* of the data is performed but the rotation angle is computed and stored in the GEOTIFF tags. The geolocation accuracy depends on the quality of the annotation data available in the header and therefore it will be much higher in ASAR products than in ERS data.
Note that an ASCII file containing some image annotations is also generated as output. Please note that no AOI selection is allowed during the export function.
* This is not true when the geo-correction routine is applied to the image. In that case the rotation is applied and the size of the image is modified according to the geocoding process.
2 - Free SW for displaying
Here is a list of Free SW which can support the user for the visualization of TIFF - GEOTIFF output-products and eventually further processing:
3 - Blank space in the path name -->Error opening file: ALL TOOLS
Due to a problem handling spaces in file paths, BEST should not make use (for input or output) of any directories with blank spaces in their names, including \My Documents. It is suggested that all input and output files are placed in a directory called e.g. C:\Data\ASAR. It is also recommended to use short folder path names of no more 120 characters.
4 - Co-registration: DORIS BASELINE EVALUATION
The computation of baselines from DORIS orbit files is not yet fully validated.
5 - Calibration
ERS GEC data processed by GEOS-2.0.2/D processor cannot be calibrated.
IMG ERS data processed by PGS-ERS processor in Envisat format cannot be calibrated.
Version 4.2.2-b permits easy calibration of ERS and ASAR images acquired until 31st December 2009.
Furthemore, it’s also possible to use new ASAR External calibration files (ASAR_XCA_AX) delivered by ESA by following a simple procedure which allows to update previous calibration files:
5b - Steps to follow to ingest ASAR External calibration data (ASA_XCA_AX) delivered by ESA.
a) Create a folder called “asar_xca” inside C:\BESTv422-b
b) Download and save the new ASA_XCA_AX files inside the C:\BESTv422-b\asar_xca folder
c) Create an ad hoc ASCII.ini file (e.g. xca_new.ini ) in the C:\BESTv422-b\asar_xca folder
d) From the command prompt (cmd) for Windows or from the Terminal for LinuX or SUN Solaris, run BEST associated with the ASCII.ini file by typing
best C:\BESTv422-b\asar_xca\ASCII.ini (e.g. best C:\BESTv422-b\asar_xca\xca_new.ini)
The step d updates the folder C:\BESTv422-b\cfg
It's possible also to create an ASCII.ini file with more than one calibration file inside as in this example file
N.B. If the XCA data is a text file, the extention .txt has to be included in the name of the file
6 - Geo Correction routine: the Nearest Neighbour interpolator could not properly work with IMP data
7 - PGS-ERS data
The PGS- ERS IMM and Browse products are not handled by BEST