l1bgen command

l1bgen

If you do not require an L1B file, but are only interested in generating an L2 file from your L1A file, l1bgen is not required, and l2gen should be used intead.

Description: This program reads in a SeaWiFS Level-1A file (HRPT, LAC, or GAC) and generates a L1B file by applying the sensor calibration at the same resolution and location as the Level-1A data. The detailed information about Level-1B HDF file format is available in "SeaWiFS Non-Archive Product Specification". Note that the solar and sensor zenith and azimuth angles will not be generated here. However, they can be calculated and loaded when a L1B file is loaded in the general display program 'seadisp'.

Command Mode:

Usage : l1bgen, ifile="ifile", ofile="ofile", spixl=spixl , epixl=epixl , dpixl=dpixl , sline=sline , eline=eline , dline=dline, sl_frac=sl_frac, sl_pixl=sl_pixl, gain=gain, offset=offset, calfile=calfile, wait=wait, help=hlp

Usage: l1bgen, par="pfile", wait=wait

Arguments/Keywords:

ifile directory path and filename of the input Level-1A data product.

ofile directory path and filename of the output Level-1B data product.

calfile directory path and filename of the calibration table file.

spixl starting pixel number to be processed. (Default=1).

epixl ending pixel number to be processed. (Default=0, meaning the end of the scanline).

dpixl pixel subsampling rate. (Default=1).

sline starting scan line number to be processed. (Default=1).

eline ending scan line number to be processed. (Default=0, meaning the last line of the file).

dline line subsampling rate. (Default=1).

gain Calibration gain factors to substitute for values read from the calibration table.

offset Calibration gain offset factors to substitute for values read from the calibration table.

sl_frac Lt 865 threshold for stray-light correction. (SeaWiFs only.) (Default = 0.25)

sl_pixl Number of LAC pixels over which stray-light correction is applied. 0 = no correction, -1 = program defaults (8 for GAC, 3 for LAC)

wait A keyword, if not set or a value 0 (default), the command will spawn the processing program as a background job and come back right away for the next SeaDAS command. Otherwise, if the keyword is set or has a value 1, the command will spawn the processing program as a foreground job and wait for it to complete before next SeaDAS command can be executed.

help to list all arguments and keywords for this program.

par input parameter file to be used in the specific command mode 'l1bgen, par="pfile"'. The parameter file may be generated in the interactive mode and used in the command mode.

Interactive Mode:

Main Widget:

The main widget can be accessed by selecting "l1bgen" from the Process->SeaWiFS pull down menu in SeaDAS main menu or from the command line mode by typing: "l1bgen".

Input items:

Input L1A file The directory path and filename of the input Level-1A data product.

Output L1B file The directory path and filename of the output Level-1B data product.

GAIN Calibration gain factors to substitute for values read from the calibration table.

OFFSET Calibration gain offset factors to substitute for values read from the calibration table.

SPIXL starting pixel number to be processed. (Default=1).

EPIXL ending pixel number to be processed. (Default=0, meaning the end of the scanline).

DPIXL pixel subsampling rate. (Default=1).

SLINE starting scan line number to be processed. (Default=1).

ELINE ending scan line number to be processed. (Default=0, meaning the last line of the file).

DLINE line subsampling rate. (Default=1).

SL_PIXL Number of LAC pixels over which stray-light correction is applied. 0 = no correction, -1 = program defaults (8 for GAC, 3 for LAC)

SL_FRAC Lt 865 threshold for stray-light correction. (SeaWiFs only.) (Default = 0.25)

CALFILE directory path and filename of the calibration table file.

Parameter file The parameter file name that the input parameters to be saved to or loaded from depending on the selection of the Option drop down menu button.

Log file The output file name to keep the process log if the user select Submit.

Action items:

Select (Input L1A file)	To display the File Selection Widget for selecting the input L1A file. The file selected will be displayed in the Input L1 File field.
Option - Load	To load and display the parameter values on the screen from the parameter file.
Option - Save	To save the parameter values displayed on the screen to the parameter file.
Option - Select	To display the File Selection Widget for selecting the parameter file.
Option - Run	To start the L1B file generation program with the parameter file.
Option - Submit	To start the L1B file generation program with the parameter file in the background.
Run	To start the L1B file generation program.
Submit	To start and run the L1B file generation program in the background.
Quit	To quit this program.

File Selection Widget:

Input items:

Path The directory from which the subdirectories and files are listed for selection.

Filter The string for filtering the files in the Path directory and displayed in the Files List for selection.

Subdirectories Listing of all the subdirectories under the Path directory. The listing will be updated if the field Path got updated.

Files Listing of all the files that are under the Path directory and match the Filter strings. The listing will be updated if fields Path, Filter, or Subdirectories got updated. If left mouse button used to click on any file, that file will be listed in the Selection field

Selection The file to be selected when the OK button is clicked. If this field is empty, the directory in the Path field is returned.

Action items:

OK Returns the selected file list in the Selection field (or Path field, if Selection field is blank), and quits the File Selection Widget

Cancel Cancels and quits the File Selection Widget. No file is selected.

Help Displays the IDL version of online help on this widget.

Curator: OceanColor Webmaster

Authorized by: gene carl feldman

ifile	directory path and filename of the input Level-1A data product.
ofile	directory path and filename of the output Level-1B data product.
calfile	directory path and filename of the calibration table file.
spixl	starting pixel number to be processed. (Default=1).
epixl	ending pixel number to be processed. (Default=0, meaning the end of the scanline).
dpixl	pixel subsampling rate. (Default=1).
sline	starting scan line number to be processed. (Default=1).
eline	ending scan line number to be processed. (Default=0, meaning the last line of the file).
dline	line subsampling rate. (Default=1).
gain	Calibration gain factors to substitute for values read from the calibration table.
offset	Calibration gain offset factors to substitute for values read from the calibration table.
sl_frac	Lt 865 threshold for stray-light correction. (SeaWiFs only.) (Default = 0.25)
sl_pixl	Number of LAC pixels over which stray-light correction is applied. 0 = no correction, -1 = program defaults (8 for GAC, 3 for LAC)
wait	A keyword, if not set or a value 0 (default), the command will spawn the processing program as a background job and come back right away for the next SeaDAS command. Otherwise, if the keyword is set or has a value 1, the command will spawn the processing program as a foreground job and wait for it to complete before next SeaDAS command can be executed.
help	to list all arguments and keywords for this program.
par	input parameter file to be used in the specific command mode 'l1bgen, par="pfile"'. The parameter file may be generated in the interactive mode and used in the command mode.

Input L1A file	The directory path and filename of the input Level-1A data product.
Output L1B file	The directory path and filename of the output Level-1B data product.
GAIN	Calibration gain factors to substitute for values read from the calibration table.
OFFSET	Calibration gain offset factors to substitute for values read from the calibration table.
SPIXL	starting pixel number to be processed. (Default=1).
EPIXL	ending pixel number to be processed. (Default=0, meaning the end of the scanline).
DPIXL	pixel subsampling rate. (Default=1).
SLINE	starting scan line number to be processed. (Default=1).
ELINE	ending scan line number to be processed. (Default=0, meaning the last line of the file).
DLINE	line subsampling rate. (Default=1).
SL_PIXL	Number of LAC pixels over which stray-light correction is applied. 0 = no correction, -1 = program defaults (8 for GAC, 3 for LAC)
SL_FRAC	Lt 865 threshold for stray-light correction. (SeaWiFs only.) (Default = 0.25)
CALFILE	directory path and filename of the calibration table file.
Parameter file	The parameter file name that the input parameters to be saved to or loaded from depending on the selection of the Option drop down menu button.
Log file	The output file name to keep the process log if the user select Submit.

Path	The directory from which the subdirectories and files are listed for selection.
Filter	The string for filtering the files in the Path directory and displayed in the Files List for selection.
Subdirectories	Listing of all the subdirectories under the Path directory. The listing will be updated if the field Path got updated.
Files	Listing of all the files that are under the Path directory and match the Filter strings. The listing will be updated if fields Path, Filter, or Subdirectories got updated. If left mouse button used to click on any file, that file will be listed in the Selection field
Selection	The file to be selected when the OK button is clicked. If this field is empty, the directory in the Path field is returned.

OK	Returns the selected file list in the Selection field (or Path field, if Selection field is blank), and quits the File Selection Widget
Cancel	Cancels and quits the File Selection Widget. No file is selected.
Help	Displays the IDL version of online help on this widget.