Stitching of same UTM zone granules

[quinten]

As of ACOLITE version 20170619.0 separate Sentinel-2A granules from the same overpass and same UTM zone can be stitched together automatically. Due to the IDL file selector widget used in the GUI this can only be done using batch mode processing using the command line.

You will need:
- a settings file containing your region of interest and processing options, this can be exported from the ACOLITE GUI: acolite_settings.cfg
- a list of the tiles you want to stitch: tiles.txt

In a terminal or the Windows command prompt, change directory to the ACOLITE directory, and run the batch mode command with merge_tiles=1 keyword. For example for linux:

idl84/bin/idl -rt=acolite.sav -args settings=acolite_settings.cfg image=tiles.txt run=1 merge_tiles=1

Please not that the full path to the settings file and image list needs to be provided. The image list file needs to contain the full path to the individual .SAFE files as well.

[quinten]

As an example, let's process the Sentinel-2A overpass over Morecambe Bay on the 25th of May. I have downloaded 4 tiles covering the bay (T30UVE, T30UVF,T30UWE,T30UWF), and saved them in a specific location. Using a text editor I create the file 'Morecambe_tiles.txt' with on new lines the full path to each tile:

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/home/quinten/Sentinel-2/Data/30UVE/S2A_MSIL1C_20170525T112121_N0205_R037_T30UVE_20170525T112434.SAFE
/home/quinten/Sentinel-2/Data/30UVF/S2A_MSIL1C_20170525T112121_N0205_R037_T30UVF_20170525T112434.SAFE
/home/quinten/Sentinel-2/Data/30UWE/S2A_MSIL1C_20170525T112121_N0205_R037_T30UWE_20170525T112434.SAFE
/home/quinten/Sentinel-2/Data/30UWF/S2A_MSIL1C_20170525T112121_N0205_R037_T30UWF_20170525T112434.SAFE

Using the ACOLITE GUI I specify an output directory and the region of interest (South 53.9399 North 54.2508 West -3.22040 East -2.77750) and click save to generate a settings file 'Morecambe_settings.cfg'. In a terminal window I change directories to the acolite_linux directory, and run the batch command:

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cd /home/quinten/acolite_linux
idl84/bin/idl -rt=acolite.sav -args settings=/home/quinten/Examples/Morecambe_settings.cfg image=/home/quinten/Examples/Morecambe_tiles.txt run=1 merge_tiles=1

When using the merge_tiles keyword I get a merged output product:

S2A_MSI_2017_05_25_11_21_merged_tiles_UTM30_RGB_RCO_LINEAR_map_small.png (171.2 KiB) Viewed 7809 times

Without the merge_tiles keyword the granules are processed separately:

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cd /home/quinten/acolite_linux
idl84/bin/idl -rt=acolite.sav -args settings=/home/quinten/Examples/Morecambe_settings.cfg image=/home/quinten/Examples/Morecambe_tiles.txt run=1

T30UVE

S2A_MSIL1C_20170525T112121_N0205_R037_T30UVE_20170525T112434_stitch_RGB_RCO_LINEAR_map_small.png (82.19 KiB) Viewed 7809 times

T30UVF

S2A_MSIL1C_20170525T112121_N0205_R037_T30UVF_20170525T112434_stitch_RGB_RCO_LINEAR_map_small.png (100.14 KiB) Viewed 7809 times

T30UWE

S2A_MSIL1C_20170525T112121_N0205_R037_T30UWE_20170525T112434_stitch_RGB_RCO_LINEAR_map_small.png (67.88 KiB) Viewed 7809 times

T30UWF

S2A_MSIL1C_20170525T112121_N0205_R037_T30UWF_20170525T112434_stitch_RGB_RCO_LINEAR_map_small.png (66.57 KiB) Viewed 7809 times