MSG -- Meteosat Second Generation
Driver short name
MSG
Build dependencies
msg library
This driver implements reading support for Meteosat Second Generation
files. These are files with names like
H-000-MSG1\_\_-MSG1\_\_\_\_\_\_\_\_-HRV\_\_\_\_\_\_-000007\_\_\_-200405311115-C\_
, commonly
distributed into a folder structure with dates (e.g. 2004\05\31
for the
file mentioned).
The MSG files are wavelet-compressed. A decompression library licensed from EUMETSAT is needed (Public Wavelet Transform Decompression Library Software, shorter Wavelet Transform Software). The software is compilable on Microsoft Windows, Linux and Solaris Operating Systems, and it works on 32 bits and 64 bits as well as mixed architectures. It is licensed under Apache v2.
Driver capabilities
Supports Georeferencing
This driver supports georeferencing
Build Instructions
See the GDAL_USE_PUBLICDECOMPWT
option of Building GDAL from source.
Specification of Source Dataset
It is possible to select individual files for opening. In this case, the driver will gather the files that correspond to the other strips of the same image, and correctly compose the image.
Example with gdal_translate.exe:
gdal_translate
C:\hrit_a\2004\05\31\H-000-MSG1__-MSG1________-HRV______-000008___-200405311115-C_
C:\output\myimage.tif
It is also possible to use the following syntax for opening the MSG files:
MSG(source_folder,timestamp,(channel,channel,...,channel),use_root_folder,data_conversion,nr_cycles,step)
source_folder: a path to a folder structure that contains the files
timestamp: 12 digits representing a date/time that identifies the 114 files of the 12 images of that time, e.g. 200501181200
channel: a number between 1 and 12, representing each of the 12 available channels. When only specifying one channel, the brackets are optional.
use_root_folder: Y to indicate that the files reside directly into the source_folder specified. N to indicate that the files reside in date structured folders: source_folder/YYYY/MM/DD
data_conversion:
N to keep the original 10 bits DN values. The result is UInt16.
B to convert to 8 bits (handy for GIF and JPEG images). The result is Byte.
R to perform radiometric calibration and get the result in mW/m2/sr/(cm-1)-1. The result is Float32.
L to perform radiometric calibration and get the result in W/m2/sr/um. The result is Float32.
T to get the reflectance for the visible bands (1, 2, 3 and 12) and the temperature in degrees Kelvin for the infrared bands (all other bands). The result is Float32.
nr_cycles: a number that indicates the number of consecutive cycles to be included in the same file (time series). These are appended as additional bands.
step: a number that indicates what is the stepsize when multiple cycles are chosen. E.g. every 15 minutes: step = 1, every 30 minutes: step = 2 etc. Note that the cycles are exactly 15 minutes apart, so you can not get images from times in-between (the step is an integer).
Examples with gdal_translate utility:
Example call to fetch an MSG image of 200501181200 with bands 1, 2 and 3 in IMG format:
gdal_translate -of HFA MSG(\\pc2133-24002\RawData\,200501181200,(1,2,3),N,N,1,1) d:\output\outfile.img
In JPG format, and converting the 10 bits image to 8 bits by dividing all values by 4:
gdal_translate -of JPEG MSG(\\pc2133-24002\RawData\,200501181200,(1,2,3),N,B,1,1) d:\output\outfile.jpg
The same, but reordering the bands in the JPEG image to resemble RGB:
gdal_translate -of JPEG MSG(\\pc2133-24002\RawData\,200501181200,(3,2,1),N,B,1,1) d:\output\outfile.jpg
Geotiff output, only band 2, original 10 bits values:
gdal_translate -of GTiff MSG(\\pc2133-24002\RawData\,200501181200,2,N,N,1,1) d:\output\outfile.tif
Band 12:
gdal_translate -of GTiff MSG(\\pc2133-24002\RawData\,200501181200,12,N,N,1,1) d:\output\outfile.tif
The same band 12 with radiometric calibration in mW/m2/sr/(cm-1)-1:
gdal_translate -of GTiff MSG(\\pc2133-24002\RawData\,200501181200,12,N,R,1,1) d:\output\outfile.tif
Retrieve data from c:hrit-data20050118 instead of \pc2133-24002RawData... :
gdal_translate -of GTiff MSG(c:\hrit-data\2005\01\18,200501181200,12,Y,R,1,1) d:\output\outfile.tif
Another option to do the same (note the difference in the Y and the N for the “use_root_folder” parameter:
gdal_translate -of GTiff MSG(c:\hrit-data\,200501181200,12,N,R,1,1) d:\output\outfile.tif
Without radiometric calibration, but for 10 consecutive cycles (thus from 1200 to 1415):
gdal_translate -of GTiff MSG(c:\hrit-data\,200501181200,12,N,N,10,1) d:\output\outfile.tif
10 cycles, but every hour (thus from 1200 to 2100):
gdal_translate -of GTiff MSG(c:\hrit-data\,200501181200,12,N,N,10,4) d:\output\outfile.tif
10 cycles, every hour, and bands 3, 2 and 1:
gdal_translate -of GTiff MSG(c:\hrit-data\,200501181200,(3,2,1),N,N,10,4) d:\output\outfile.tif
Georeference and Projection
The images are using the Geostationary Satellite View projection. Most GIS packages don't recognize this projection (we only know of ILWIS that does have this projection), but gdalwarp.exe can be used to re-project the images.
See Also
Implemented as msgdataset.cpp.
http://www.eumetsat.int - European Organisation for the Exploitation of Meteorological Satellites