SeaDAS Banner Image

bl3map

Description: SeaWiFS and MODIS Level-3 binned data files need to be map projected in order to be viewed. The bl3map  program map projects selected products from SeaWiFS or MODIS Level-3 Binned files and outputs the selected map projections to an HDF file. This HDF file stores the map projected data as HDF SD's along with the specified mapping attributes and is referred to as a SeaDAS Mapped file in SeaDAS.  SeaDAS Mapped files  can be displayed and navigated using the Load->SeaDAS Mapped option in the seadisp program.

The resultant output map projections do not perform any additional rebinning operations.  A single point from the input L3-binned file is selected to fill each pixel in the ouptut projected map. It is up to the user to select the appropriate resolution for their input data.  Selecting a resolution that is lower than your input data will result in a subsampled effect. Selecting a resolution that is greater than your input data will result in a zoomed effect.

The map projections are created using IDL's map projection capabilites. See Map Projection Keywords - Meanings and Defaults  for a brief description of the available map projections and map projection keywords For more detailed information about the specific mapping parameters, see the description about the MAP_SET and MAP_IMAGE functions in the IDL Reference Guide.

[Command Mode][Interactive Mode]


Command Mode:

Usage: bl3map, ifile, ofile, product_cat, append=append, help=hlp, map_pfile=map_pfile, iproj=iproj, xsize=xsize, ysize=ysize, position=position, p0lat=p0lat, p0lon=p0lon, rot=rot, limit=limit, title=title, missing=missing, source=source, isotropic=isotropic, scale=scale, ellipsoid=ellipsoid, central_azimuth=central_azimuth, standard_parallels=standard_parallels, /CYLIN, /MERCATOR, /MOLLWEIDE, /STEREOGRAPHIC, /ORTHOGRAPHIC, /CONIC, /LAMBERT, /GNOMIC, /AZIMUTHAL, /SINUSOIDAL, /AITOFF, /HAMMER, /ALBERS, /MILLER, /TRANSVERSE_MERCATOR, /ROBINSON, /SATELLITE

Minimum Command:  bl3map, ifile, ofile, product_cat

Examples:

(1) bl3map, '$SDSDEMO/l3_daily1.hdf', 'l3map.hdf', [['nLw_490','1'], ['chlor_a','1'], ['nLw_490','2'], ['chlor_a','2']], xsize=200, ysize=300, /stereo
(2) bl3map, '$SDSDEMO/l3_daily1.hdf', 'l3map.hdf', [[2,1], [5,1]], xsize=300,ysize=400, /merc, POSITION=[0.2,0.2,0.8,0.8]

Arguments/Keywords:
 
ifile Input SeaWiFS or MODIS Level-3 Binned file name. (Required)
ofile The output HDF file name for the mapped Level-3 product images.  If the file already exists, it must be an HDF file and the mapped images will be appended to it as SD objects. (Required)
product_cat An array of pairs.(Required) 
The first element of the pair is the name of the Level-3 product. 
The second element of the pair is the number corresponding to the desired statistical measure.   See below. 
The array should be a string array as in example(1), above. 
NOTE:  In previous versions of SeaDAS, product numbers were used instead of product names.   Since some users may have old scripts using product numbers, the following numbers may still be used in place of product names:
    First element of pair:
    Product number: For product name:
    1 nLw_412
    2 nLw_443
    3 nLw_490
    4 nLw_510
    5 nLw_555
    6 La_670
    7 CZCS_pigment
    8 chlor_a
    9 K_490
    10 chlor_a_K490
    11 eps_78
    12 tau_865
When using product numbers instead of names, the array product_cat should be an integer array instead of a string array, as in example (2) above.  For all products not listed above, product names must be used instead of product numbers.

Second element of pair:
Mean
2 Variance
3 Standard deviation
4 Sample (the number of Level-2 input values that went into creating the Level-3 bin that was selected as mapping to this grid point)
5 Segment (the number of Level-2 input files that went into creating the Level-3 bin that was selected as mapping to this grid point)
in
Each product specified will be written to ofile as an SD object with SD name(s) attributes as specified in title Note that 'sample' and 'segment' will yield the same output no matter what is used for the product name.

append 0 = Remove output file if exists and create a new HDF file. (default)
Non_zero = append all SD's to existing file
map_pfile The name of an optional ASCII file which contains the map projection keyword values.
Map Projection Keywords - Meaning and Defaults Click here for a full description.
Note: All projection keywords are stored as SD attributes in the output file.
title The SD name(s) to assign to the mapped SD's. If not specified, the default product names are used.
missing An array of missing values to use for any unmapped areas for the products specified in product_cat.  If not specified, the missing value to use for each product is searched for in the  seadas_defaults file. If the product is not listed in the defaults file, then 0.0 is used.  The missing values are specified in terms of floating-point geophysical values.
source The source of the mapped image as an attribute to the SD object written to the output HDF file. Default is ifile.
help To list all arguments and keywords available for this program.


Interactive Mode:

Main widget:

The main widget can be accessed by selecting "bl3map" from the Process->SeaWiFS or Process->MODIS pull down menu in SeaDAS main menu or from the command line mode by typing: "bl3map".
 
Input file The input SeaWiFS or MODIS Level-3 file.
Select (Input file) To display the File Selection Widget for selecting the input Level-3 file.  The file selected will be displayed in the Input File field.
Output file The output HDF file name for the mapped Level-3 images.  If the file already exists, it has to be an HDF file and the mapped Level-3 images will be appended as SD objects in it.
Output File Mode Action to take if output HDF file already exists.
    New - Remove the existing HDF file before creating a new file (default)
    Append- Append output SDs to the existing HDF file.
Selected output products section (This section is not visible until an input file has been selected.)
 
Measure Toggle buttons to select the statistical values to be calculated. The selections of this field (except Sample and Segment) combined with selections of Product determine the products to be added to the Output list when the Add button is pressed.  Since categories Sample and Segment are for all products, they don't combine with any of the Products.
Product Toggle buttons to select the products in the L3 Binned file to be projected. The selections of this field combined with selections of Measure field determine the products to be added to the Output list when the Add button is pressed.
Output list Click on an entry in this list to highlight it for deleting when the Delete button is pressed. The title for the highlighted output selection will also be loaded into the Title field for update.
Add To add the outputs selected in Product and Category to the Output list field.
Clear To remove all the entries listed in the Output list field.
Delete To delete the highlighted entry in the Output list field.
Title The SD name for the mapped product of the highlighted item in the Output list. This name is used to identify this SD within the output HDF file.
Missing The missing values to use for unmapped areas, for each product selected.  Leaving this blank denotes to take the default behavior.  See missing keyword in command mode.
Map Projection In Map Projection Compound Widget
Log file The output file name for the process log if the user select Submit.
Run Run this program in the foreground using the options specified.  Process log messages will print to the main SeaDAS window.
Submit Run this program as a background process using the options specified.
Help Display this HTML help file in local HTML viewer.
Quit 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 the left mouse button is 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

NASA logo

Privacy Policy and Important Notices

Updated: Thursday, 11-Dec-2008 10:52:36 EST