l1agen_seawifs command

l1agen_seawifs

Description: This program reads in SeaWiFS Level 0, 10-bit Data Capture Facility (DCF) frame-formatter files and creates a Level-1A file in Hierarchical Data Format (HDF) for each scene. Level 1A image data are raw, and all spacecraft and instrument telemetry are retained in raw form as in the Level 0 data. In addition, geolocation data, instrument telemetry and selected spacecraft telemetry are converted and appended.

NOTE: This program is primarily for HRPT stations, since no Level-0 data will be archived and distributed by the Goddard DAAC.

NOTE: See additional information on navigation files which must be kept up-to-date.

Command Mode:

Usage : l1agen_seawifs, ifile="ifile", out="out", maxbiterr=maxbiterr, hrptgacflag=hrptgacflag, gainflag=gainflag, mailflag=mailflag, wait=wait, help=hlp

Minimum Command: l1agen_seawifs, ifile="ifile"

Example: l1agen_seawifs, ifile="/home/seadas/L0.hdf", out="/home/seadas/L1A.hdf", maxbiterr=50, mailflag=1, wait=1, help=1

Arguments/Keywords:

ifile Input SeaWiFS HRPT, GAC, or LAC L0 file. (Required)

out The output directory or file name for the L1A output. The default (if not specified) is the current directory. If an output directory is entered, the default naming convention for the L1A output is specified in "SeaWiFS OPERATIONAL PRODUCT SPECIFICATIONS" for the Level-1A data.

maxbiterr The maximum number of bit errors allowed for processing each frame. A portion of each scan line has a predetermined bit pattern that can be examined for errors. If a bit does not match what is expected, this indicates errors in the transmission of the data. Setting the maxbiterr value is a way to increase or decrease the number of frames included in the processing, which affects how "clean" the resulting L1A file will be. For LAC/HRPT data, there is one scan line per frame. For GAC data, there are 5 scan lines per frame. If the maximum number of bit errors is reached for a particular frame, then that frame is dropped. Set this value to a large number to include all frames in the processing, regardless of errors (> 140 for LAC/HRPT, > 350 for GAC). 50 is a good default value because it will generally just toss encrypted lines, which register a constant bit error count of 65-72, depending on the encryption key. (Default=50).

hrptgacflag Force HRPT or GAC processing. 0=HRPT, 1=GAC. (Default=0)

gainflag Force gain settings to zero, or set gain from file telemetry. 0=From telemetry, 1=0. (Default=0 if hrptgacflag=0, else default=1)

mailflag The flag, if set with a value not 0, to generate the mailfile to send to SeaWiFS project. The mailfile will have the '.meta' extension appended to the corresponding output L1A file.

wait A keyword, if not set or a value 0 (default), the command will spawn the l1agen_seawifs processing program as a background job and come back right away for the next SeaDAS command. Otherwise, if the keyword is set or with a value of 1, the command will spawn the l1agen_seawifs processing program as a foreground job and wait for it to complete before the next SeaDAS command can be executed.

help To list all arguments and keywords available for this program.

Interactive Mode:

Main Widget:

The main widget can be accessed by selecting "l1agen_seawifs" from the Process->SeaWiFS pull down menu in the SeaDAS main menu or from the command line mode by typing: "l1agen_seawifs".

Input items :

Input L0 file The input SeaWiFS L0 file. It can be a LAC, GAC, or HRPT file.

Select (Input L0 file) To display the File Selection Widget for selecting the input L0 file. The file selected will be displayed in the Input L0 File field.

Output directory or file The output directory or file for the L1A file to be generated. If an output directory is entered, the default naming convention for the L1A output file is used. This default naming convention is specified in "SeaWiFS OPERATIONAL PRODUCT SPECIFICATIONS".

Maximum number of bit errors/frame See maxbiterr keyword above in command mode.

Data type HRPT or GAC. (Default=HRPT)

Gain setting From telemetry, or 0. (Default=0)

Select (Output directory) To display the File Selection Widget for selecting the output directory. The directory selected will be displayed in the Output directory field.

Generate Mail File for SeaWiFS Project Option to allow this program to generate an extra ASCII file to send to the SeaWiFS project. The mailfile will have the '.meta' extension appended to the corresponding output L1A file.

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

Run Starts the SeaWiFS L1A file generation program.

Submit Starts and runs the SeaWiFS L1A file generation program in the background.

Help Display the HTML help for this program in the user's HTML viewer.

Quit Quits 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	Input SeaWiFS HRPT, GAC, or LAC L0 file. (Required)
out	The output directory or file name for the L1A output. The default (if not specified) is the current directory. If an output directory is entered, the default naming convention for the L1A output is specified in "SeaWiFS OPERATIONAL PRODUCT SPECIFICATIONS" for the Level-1A data.
maxbiterr	The maximum number of bit errors allowed for processing each frame. A portion of each scan line has a predetermined bit pattern that can be examined for errors. If a bit does not match what is expected, this indicates errors in the transmission of the data. Setting the maxbiterr value is a way to increase or decrease the number of frames included in the processing, which affects how "clean" the resulting L1A file will be. For LAC/HRPT data, there is one scan line per frame. For GAC data, there are 5 scan lines per frame. If the maximum number of bit errors is reached for a particular frame, then that frame is dropped. Set this value to a large number to include all frames in the processing, regardless of errors (> 140 for LAC/HRPT, > 350 for GAC). 50 is a good default value because it will generally just toss encrypted lines, which register a constant bit error count of 65-72, depending on the encryption key. (Default=50).
hrptgacflag	Force HRPT or GAC processing. 0=HRPT, 1=GAC. (Default=0)
gainflag	Force gain settings to zero, or set gain from file telemetry. 0=From telemetry, 1=0. (Default=0 if hrptgacflag=0, else default=1)
mailflag	The flag, if set with a value not 0, to generate the mailfile to send to SeaWiFS project. The mailfile will have the '.meta' extension appended to the corresponding output L1A file.
wait	A keyword, if not set or a value 0 (default), the command will spawn the l1agen_seawifs processing program as a background job and come back right away for the next SeaDAS command. Otherwise, if the keyword is set or with a value of 1, the command will spawn the l1agen_seawifs processing program as a foreground job and wait for it to complete before the next SeaDAS command can be executed.
help	To list all arguments and keywords available for this program.

Input L0 file	The input SeaWiFS L0 file. It can be a LAC, GAC, or HRPT file.
Select (Input L0 file)	To display the File Selection Widget for selecting the input L0 file. The file selected will be displayed in the Input L0 File field.
Output directory or file	The output directory or file for the L1A file to be generated. If an output directory is entered, the default naming convention for the L1A output file is used. This default naming convention is specified in "SeaWiFS OPERATIONAL PRODUCT SPECIFICATIONS".
Maximum number of bit errors/frame	See maxbiterr keyword above in command mode.
Data type	HRPT or GAC. (Default=HRPT)
Gain setting	From telemetry, or 0. (Default=0)
Select (Output directory)	To display the File Selection Widget for selecting the output directory. The directory selected will be displayed in the Output directory field.
Generate Mail File for SeaWiFS Project	Option to allow this program to generate an extra ASCII file to send to the SeaWiFS project. The mailfile will have the '.meta' extension appended to the corresponding output L1A file.
Log file	The output file name to keep the process log if the user selects Submit.
Run	Starts the SeaWiFS L1A file generation program.
Submit	Starts and runs the SeaWiFS L1A file generation program in the background.
Help	Display the HTML help for this program in the user's HTML viewer.
Quit	Quits this program.

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.