4SM SPOT arcachon-prepare-your-image

0 - Get acquainted with this image
1 - Prepare shapefiles
2 - Run the AutoCAL command line script
- Create the database arcachon.pix
- Compute glint regressions (does not apply here)
- Write the special effects mask mSE in channel 4
- Extract the calibration data
- Map the PL pixels
- Perform an automatic calibration
- Deglint the image (does not apply here)
3 - Output of the AutoCAL process
- Display a calibration diagram
- Write and display the 4SM command line for the next step

1 - Prepare Shapefiles

Downloads and installs

Download 4sm_tutorial_arcachon.zip
and place it in a 4sm_tutorial_arcachon directory
unzip it : you get
- ~/4SM_tutorials/4sm_tutorial_arcachon/data/....................................arcachon-full.tif
- ~/4SM_tutorials/4sm_tutorial_arcachon/data/....................................arcachon-full.opf
- ~/4SM_tutorials/4sm_tutorial_arcachon/4SM.4.08.............................uptodate 4SM executable code
- ~/4SM_tutorials/4sm_tutorial_arcachon/4sm.calls.............................directory for various system calls
- ~/4SM_tutorials/Caicos/FWTools-linux-2.0.6.tar.gz...........................OpenEV
- ~/4SM_tutorials/4sm_tutorial_arcachon..............................................various_shapfiles
- ~/4SM_tutorials/4sm_tutorial_arcachon/arcachon.sh.........................command line script?
NOTE: 4sm.calls is missing. Shall be copied from Tarawa tutorial

4sm.calls

cp -r ~/4SM_tutorials/4sm_tutorial_tarawa/4sm.calls .

Raw data is stored in Arcachon/data/arcachon-full.tif

Use OpenEV to

Export arcachon-full.tif into arcachon-full.pix in PCIDSK format
Georeferencing :
- the image is 1200 rows and 2000 lines
- it is UTM projected, but not georeferenced
- pixel size is 20 m
- therefore, the origin of this image is
  - Origin_XUM=0.0 km
  - Origin_YUTM=2000*.02=40.0 km
  - FalseNorthing=FalseEasting=0 km (i.e. un-known)
Display : use the arcachon-full.opf project to display a FCC of arcachon-full.pix
Import Shapefile :
- draw a rectangular polygon to specify your area of interest
- and save it in your work directory as 4sm_tutorial_arcachon/import.shp

Now you need to draw several shapefiles inside your area of interest
and save them in the work directory,
ready for use in the AutoCAL process:

4sm_tutorial_arcachon/Lsw.shp
4sm_tutorial_arcachon/LsM.shp
4sm_tutorial_arcachon/vegetation.shp (of no use as there is no blue band)

There is no obvious lumps of haze or swell-modulated sea-surface glint in the NIR band of the area of interest.
- Therefore no deglinting shall be applied

NIR RED GREEN
radiances are smoothed

2 - Run the AutoCAL script

Database structure
Learn about the command line
The AutoCAL script
Prepare the AutoCAL script

run the AutoCAL commandline

nice -20 ./4SM.4.08 -Process/06_JUL_2011 -Origin/SPT @@

-DB/arcachon/27_1_0_0/3_1/500_630/0.01_22.61/1_1 @@

-Mis/Arcachon/France/Spot/XS/NA/UTM_1_008/0.02_0.02/01_AUG_1986 @@

-MakePIX @@

-Import/data*arcachon-full/dbnc_3_0_0_0/R1200_L2000/OriginOrigin_0.0_40.0_0_0/import.shp @@

-LsM/078.8/071.2/065.2_cLM=0.450 @@

-AutoCAL

For some reason (october 2017),
the AutoCALprocess in ./4SM.4.08 does not complete the LsM_Optimizer step.

Still, please check that

arcachon.pix has been created and loaded with the raw data
the mask mSE has been created in channel 4
the calibration data text file has been created: arcachon_m0.cal
- open it: gedit arcachon_m0.cal

The textfile autoCAL.txt is incomplete

?open it : gedit autoCAL.txt

Here is the command line that should have been written:

#Following is the simplified AutoCAL CommandLine=====mBPL=2====================
nice -20 ./4SM.4.08 -Process/14_Jul_2011/06_JUL_2011 -OriginSPT @@
-DB/arcachon/27_1_0_0/3_1/500_630/0.010_22.610/1_1 @@
-Mis/Arcachon/France/Spot/XS/NA/UTM_1_008/0.020_0.020/1_AUG_1986 @@
-LS/0255.0/255.0/255.0 @@
-M/0000001/00002/00003 @@
-LsM/139.7/140.8/099.2_AutoCAL @@
-Lsw/030.4/014.2/008.0 @@
-Lw/0001.5/000.0/000.0 @@
-Lm/0001.0/001.0/255.0 @@
-Lm/0004.0/002.0/005.0 @@
-Lm/0002.0/002.0/002.0 @@
-KK1_2_0.5595/Knir4.500/mask_1 @@
-Z/MSL0.00/cZ1.000 @@
-B/tclNe/LBref135_100/Bmin110/cLM1.00 @@
@B/tclNe/Bmin0/cLM0.45 @@
@deglint/vRbaD/GlintM25.0 @@
-extract/v/mBPL2 @@
-Calibrate/v/BdSNpZg/BDh_12_13 @@

3 - The output of the AutoCAL process

Notice the system of breaking waves	The water line is ill defined
BPL pixels for the pair 1_3 Too many BPL pixels are breaking waves	BPL pixels for the pair 1_2 Too many BPL pixels are breaking waves
	AutoCalibration failed Too many breaking waves are picked up as BPL pixels ?The AutoCalibration failed In order to get a clean calibration, we shall ?improve the present calibration perform a first modeling mask the breaking waves then start all over again
Green vs Red this sandy formation is present as clean sands over the whole depth range: as evidenced by a strong mode in the bi-dimensional histogram LsM_green~=65 and LsM_red~=60 ?the slope of this mode Kgreen/Kred is ~=0.50	Green-Red vs NIR LsM_NIR~=60 There are no clouds in this scene Wave breakers are abundant ?see that they display just like if they were clouds they must be masked out