l1aextract_modis

l1aextract_modis

Creates an extracted L1A MODIS file.

Location
Details
Command Line Usage

Location

SeaDAS-OCSSW -> extractor

Details

l1aextract_modis extracts a MODIS Level 1A sub-scene from an input Aqua or Terra L1A and GEO file. Users can specify a sub-scene either using longitude/latitude of southwest and northeast corners (swlon, swlat, nelon, nelat) or using start/end pixel numbers in conjunction with start/end lines. The former is referred to as lon/lat arguments and the latter is referred as pixel arguments. Once a user choose to specify the sub-scene using the lon/lat option, all four arguments must be specified. The program will fail to extract if any argument is missing.

Alternatively, users can directly specify pixel arguments to extract a sub-scene.

l1aextract_modis GUI

Arguments/Keywords
UI Element Name Type Description Required/Optional Default Value
infile Text Field Input MODIS Aqua or Terra L1A file to be extracted, or an L1A filelist for multiple file extraction. (Required) Required
ofile Text Field Output filename for the L1A extracted subscene. A default ofile name is generated by the program. Required
swlon Text Field Longitude of southwest corner of the box to be extracted. Conditional
swlat Text Field Latitude of southwest corner of the box to be extracted. Conditional
nelon Text Field Longitude of northeast corner of the box to be extracted. Conditional
nelat Text Field Latitude of northeast corner of the box to be extracted. Conditional
spixl int Starting pixel in infile for extracting. Conditional
epixl int Ending pixel in infile for extracting. Conditional
sline int Starting line in infile for extracting. Conditional
eline int Ending line in infile for extracting. Conditional

Actions/Buttons
UI Element Name Type Description
Browser Button Button Selects infile/ofile
Compute PixLines from LonLat Button Derives spixl, epixl, sline, and eline arguments from swlon, swlat, nelon, and nelat arguments by internally executing the lonlat2pixline program.
Load Parameters ... Button Reads in previously saved parameters and populates the fields in GUI.
Store Parameters ... Button Saves the current arguments in GUI in a file.
Run Button Executes the l1aextract_modis command with arguments provided in the UI.
Cancel Button Closes current processor GUI.
Apply Button Makes current arguments effective.
Open in SeaDAS Checkbox If selected, the ofile will be added to the open products list right after its generation.
? Button Displays the help content of the current command.

Command Line Usage

 
Usage: l1aextract_modis infile spixl epixl sline eline outfile
   where:
        infile   - input MODIS L1A datafile
        spixl    - start pixel number (1-based)
        epixl    - end pixel number (1-based)
        sline    - start line (1-based)
        eline    - end line (1-based)
        outfile  - output file name

Note: Enter line number NOT scan number!