PARSE_NSIDC_FILENAME

Name

Purpose

The purpose of this routine is to parse the name of an NSIDC image
file so that the program can call the specific file reading program
that returns the image and information about the image. When this
information is provided, this program creates and returns an
NSIDC image object.

If you wanted to modify the DataViewer program, for example, to
read another type of NSIDC image, you would first add a section
to this file that could identify an image of that type from its
filename. Then you would call the reader for that program (which
you would also have to write). The reader would read the file,
extract the image and information about the image, which this
program can then package into the NSIDC image object.

Author

David W. Fanning, Ph.D
National Snow and Ice Data Center (NSIDC)
NSIDC/CIRES University of Colorado
Boulder, CO 80309
E-Mail: fanning@nsidc.org

Syntax

nsidcImage = Parse_NSIDC_Filename(filename)

Return Value

nsidcImage: Either an NSIDC_IMAGE object, or the actual image data, depending
upon whether the RETURN_IMAGE keyword is set.

Arguments

filename: The name of an NSIDC image file. Or, alternatively, any
the name of any image file capable of being read by READ_IMAGE.
That is JPEG, PNG, TIFF, etc. files.

Input Keywords

RETURN_IMAGE: Set this keyword to have the function return the actual image
data, rather than packaging the image up into an NSIDC_IMAGE
object.

Output Keywords

INFO: An output structure containing information about the image. The structure
varies, depending upon the image, but a typical structure looks like this:

info = {directory : "", $ ; The image directory
filename: "", $ ; The image file name
extension: "", $ ; The image file extension
gpd: "", $ ; The geographical location
year: 0, $ ; The year
doy: 0, $ ; The day-of-year.
missing: 0.0, $ ; The missing value.
nsidc_tag: "", $ ; An image tag, e.g., nsidc-0032
direction: "", $ ; The direction of satellite travel
frequency: "", $ ; The frequency of radiation sampled
polarization: "", $ ; The image polarization
colorChangeAllowed: 0, $ ; Set to 1 if color change allowed for image
colorChangeNColors: 0, $ ; Number of colors that can change in image
xsize: 0, $ ; The X size of the image
ysize: 0, $ ; The Y size of the image
sclmin: 0.0, $ ; The minimum value for image scaling.
sclmax: 0.0, $ ; The maximum value for image scaling.
mapinfo: {mapStruct:mapStruct, xrange:xrange, yrange:yrange} } ; Map information.

SUCCESS: Set to 1 if the file was successfully read, otherwise to 0.

Modification History

Written by: David W. Fanning, 23 June 2008.
Added nsidc-0342 SSM/I Near Real Time Brightness Temperatures. 22 June 2009. DWF.