How to create a TrueColor image?

[ebradbury]

Hello,

I'm a new user trying to learn how to use SeaDAS and the command line tools create a highest possible resolution TrueColor image (and later an animation) such as this one: https://oceancolor.gsfc.nasa.gov/gallery/feature/images/A2014270171500.GulfOfMaine.jpg.

It seems like reproducing a TrueColor image from raw (modis level1?) data might be a good way to learn how to access and process data. I would like to do the same with SST.

Some questions I have...
- Most of the products seem to be at 4km max resolution... can we get higher resolution by processing ourselves?
- Are there tools for removing clouds from generated images?
- How do you georeference the images?
- Are there NASA tools for producing animations or is this up to the end user?

Thanks for the help!

[OB SeaDAS - xuanyang02]

You can use mapgen to create a true color image with --use_rgb option -- https://seadas.gsfc.nasa.gov/help-8.2.0/processors/ProcessMapgen.html#cl

Code: Select all

mapgen --ifile A2010283180500.L1B_LAC --geofile A2010283180500.GEO --use_rgb

The generated true color image has cloud already removed.

Modis L2 files have resolution at 1km and they are already geo-referenced.

SeaDAS does not have tools to produce animations.

[ebradbury]

Thank you for your reply.

I'm running `mapgen` and got an error: "Unrecognized HDF-EOS file A2013208173500.L1A_LAC"

I downloaded the input file from here: https://oceancolor.gsfc.nasa.gov/cgi/browse.pl?sub=level1or2&per=CU&day=19095&prm=TC&set=10&mon=19052&sen=amod@tmod@vrsn@vrj1&rad=0&frc=1&rgn=GeorgesBank&id=1649864421.1882237&cn=42.88&cs=39.64&cw=-69.05&ce=-65.34&dnm=D&file=A2013208173500.L1B_LAC_BRS_BRS&ndx=15483&wid=170&hgt=254

Then extracted it using `bzip2` and ran `mapgen --ifile A2013208173500.L1A_LAC --geofile A2013208173500.GEO --use_rgb`.

I noticed that your example uses a `.L1B_LAC`... could that be the issue?

[OB SeaDAS - xuanyang02]

Yes, mapgen with --use_rgb option needs L1B + GEO files as input

You can create an L1B file with modis_L1B --https://seadas.gsfc.nasa.gov/help-8.2.0/processors/ProcessModis_L1B.html#cl

Code: Select all

modis_L1B A2010283180500.L1A_LAC  A2010283180500.GEO

[ebradbury]

Thank you - I was able to generate a TC image using these commands...

`modis_GEO A2013208173500.L1A_LAC`
`mapgen --ifile A2013208173500.L1B_LAC --geofile A2013208173500.GEO --use_rgb --oformat tiff --resolution 1km --projection mercator`

Am I correct that this command will generate the highest possible resolution?
How can I achieve cloud removal?

Thank you

(Attached file is for reference... I had to downscale it to meet the upload size limit)

[fbecker23]

Hi everyone!
I'm reopening this topic because I've tried to make a TC image and I get and error.
I downloaded the image from MODIS "A2024300194500.L1A_LAC". My first step was create .geo file with this comand

modis_GEO path/A2024300194500.L1A_LAC

after this command, I got the file path/AQUA_MODIS.20241026T194500.GEO.hdf, with an extention ".hdf", is it ok?
Then when I've tried to make the L1B file, I got an error. I execute the command line:

modis_L1B path/A2024300194500.L1A_LAC path/AQUA_MODIS.20241026T194500.GEO.hdf

the error said:
MODIS Aqua L1B version 6.2.1_obpg, built Nov 28 2022 12:23:25
ERROR: MODIS L1B processing failed.
Please examine the LogStatus and LogUser files for more information.

and the LogStatus and LogUser files said:
LogStatus
#################
#################

****************************************
BEGIN_PGE: Wed Nov 20 15:14:29 2024
MSG_TAG: 11
FILE: /home/fernando/Escritorio/Imagenes_MODIS/prueba/LogStatus.AQUA_MODIS.20241026T194500.L1B.hdf
LOGGING: status message logging enabled
TRACE_LEVEL: tracing disabled
PID_LOGGING: disabled
DISABLED_LEVELS: none
DISABLED_SEEDS: none
DISABLED_CODES: none
THREAD-SAFE MODE: disabled
TOOLKIT_VERSION: SCF TK5.2.20
****************************************

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!! W A R N I N G !!
!! The Toolkit version found in the PCF does not !!
!! match the current Toolkit version. The PCF in use !!
!! should be replaced with a PCF constructed from the !!
!! template PCF delivered with THIS version of the !!
!! Toolkit (see TOOLKIT_VERSION in banner, above). !!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

TDLUT_ReadPiecewiseLinearFunction():MODIS_F_NOK:295817224
LUT associated with "m1" has times out of order.


Read_L1B_SDS_LUT():MODIS_F_NOK:295817224
Call to TDLUT_ReadPiecewiseLinearFunction() failed.


Read_LUT_Tables():MODIS_F_NOK:295817224
Call to Read_L1B_SDS_LUT() failed.
File LUN: 700050
File type: Reflective_Lookup_Tables_file


:MODIS_F_NOK:295817224
Fatal error(NOK) running...MOD_PR02. TIME:Wed Nov 20 15:14:29 2024
Operator Actions:
Contact MCST.
#################
#################



LogUser
#################
#################

****************************************
BEGIN_PGE: Wed Nov 20 15:25:44 2024
MSG_TAG: 11
FILE: /home/fernando/Escritorio/Imagenes_MODIS/prueba/LogUser.AQUA_MODIS.20241026T194500.L1B.hdf
LOGGING: status message logging enabled
TRACE_LEVEL: tracing disabled
PID_LOGGING: disabled
DISABLED_LEVELS: none
DISABLED_SEEDS: none
DISABLED_CODES: none
THREAD-SAFE MODE: disabled
TOOLKIT_VERSION: SCF TK5.2.20
****************************************

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!! W A R N I N G !!
!! The Toolkit version found in the PCF does not !!
!! match the current Toolkit version. The PCF in use !!
!! should be replaced with a PCF constructed from the !!
!! template PCF delivered with THIS version of the !!
!! Toolkit (see TOOLKIT_VERSION in banner, above). !!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

#################
#################