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Data Set ID:
NSIDC-0375

WAIS Divide Ice Core Images, Antarctica, Version 1

This data set is comprised of optical images of ice core sections, acquired with a digital line-scan camera in the cold room facility at the U.S. National Ice Core Laboratory (NICL). Ice core sections are archival cuts which have rough-out rounds of ice with a single plane cut along one side. Ice sections were illuminated with fiber optic light guides connected to a 1000 watt (W) xenon light source. Original scan resolution varies from about 0.05 mm to 0.1 mm, and is documented in the metadata for each image. Images are in uncompressed Tagged Image File (.tif) form, with resolutions of 1.0 mm and 0.1 mm. Depth of image in the ice core is documented in the metadata files for each image.

Data are available via FTP as .tif image files. Supporting information is available as ASCII text files (.txt), and other file formats readable with a freely available image processing program, IceImageJ.

Geographic Coverage

Parameter(s):
  • Ice Core Records
  • Visible Wavelengths > Visible Imagery
Spatial Coverage:
  • N: -79.466667, S: -79.466667, E: -112.083333, W: -112.083333

Spatial Resolution: Not Specified
Temporal Coverage:
  • 1 January 2006 to 30 December 2007
Temporal Resolution: Not specified
Data Format(s):
  • TIFF
Platform(s) Not specified
Sensor(s): Not specified
Version: V1
Data Contributor(s): Kenneth McGwire
Data Citation

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

McGwire, K. C. 2010. WAIS Divide Ice Core Images, Antarctica, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5348H8T. [Date Accessed].

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Detailed Data Description

Format

Data are available as Tagged Image File (.tif) image files. Metadata for each image is available in an ASCII text (.txt) file. Supporting information for image files is available in Report Object Instance (.roi), Audio Interchange File Format (.aiff), and Pro Tools Session (.pts) formats, readable by freely available image processing software, IceImageJ.

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File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/mcgwire_nsidc_0375/ directory. The data are in two folders, which correspond to the image resolution (1.0 mm and 0.1 mm). The directory also contains a readme file in ASCII text format.

Within each folder, numbered folders correspond to the scan number, 001 to 577. Each numbered file contains two folders, names PD_1.10 and ScanFiles. The PD_1.10 folder contains .tif image files, and a text file corresponding to each image file. The ScanFiles folder contains ancillary information acquired during the ice core scan, which can be read by IceImageJ software, which is freely available. For more information, or to download the image processing software, visit the Desert Research Institute Department of Earth and Ecosystem Sciences Web site.

Figure 1. Directory Structure on the FTP Site
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File Naming Convention

Files are named according to the following convention and as described in Table 1:

WDC06A-x-x-ymm.zzz

Where:

Table 1. File Naming Convention
Variable Description
WDC06A Ice core identification
-x-x- Scan number
ymm Image resolution, in milimeters
.zzz File extension
 

File Extensions

The data set also contains image information, in .roi, .pts, and .aiff formats, that can be read using IceImageJ, freely available image processing software. IceImageJ and additional information are available from the Desert Research Institute Department of Earth and Ecosystem Sciences Web site. Table 2 describes the information contained in the various file formats.


Table 2. File Extension Descriptions
Extension File Contents
.tif Ice core image
.txt In PD_1.10 folder: metadata for .tif ice core image
In ScanFiles folder: metadata for original ice core scan
.roi Mask indicating areas of ice image that are background or where ice is fractured
.pts Location of points automatically identified on a calibration target
.aiff Audio file with comments the scanning personnel may have made during scan
 

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File Size

Files in this data set range in size from 4 KB to about 1 MB.

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Volume

The total volume of the data set is about 16 GB.

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Spatial Coverage

This data set contains images of ice core sections from the West Antarctic Ice Sheet Divide ice core WDC06A.

Southernmost Latitude: 79°29.058'S
Northernmost Latitude: 79°29.058'S
Westernmost Longitude: 112°05.189'W
Easternmost Longitude: 112°05.189' W

Spatial Coverage Map

map with red dot showing ice core location
Figure 2. Location Map
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Temporal Coverage

Ice core images in this collection were scanned in 2006 and 2007.

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Parameter or Variable

This data set contains optical ice core images in .tif file format. Supporting files for each image, in ASCII text format, provide detailed information on scan resolution, depth of ice core image, and camera settings. Additional files provide information readable by the IceImageJ image processing software. For more information or to download the IceImageJ software, visit the Desert Research Institute Department of Earth and Ecosystem Sciences Web site.

Sample Data Record

The following examples show a sample data image, WDC06A-2-1-1.0mm.tif. Scan information for this file is available in the text file, WDC06A-2-1-1.0mm.txt.

sample data image
Figure 3. Sample Data Image
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Software and Tools

Data are accessible using image processing software. IceImageJ software is a modification to the java-based ImageJ program that was developed for the National Institutes of Health by Wayne Rasband. ImageJ is available from the National Institutes of Health. The IceImageJ modification and additional information are available from the Desert Research Institute Department of Earth and Ecosystem Sciences Web site.

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Data Acquisition and Processing

Data Acquisition Methods

Images were sidelit on both sides with fiberoptic paddles. Ice sections were cut and planed on the side that is imaged and left as a 'rough-out' half-round on the backside. Original images were scanned at varying resolution, but generally finer than 0.1 mm. Data products in this dataset have been low-pass filtered with a windowed sinc filter with a full-width half-maximum of 1.0 mm and resampled to a 1.0 mm resolution in both dimensions.

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Sensor or Instrument Description

Images were collected with a digital line-scan camera during the core processing line at the U.S. National Ice Core Laboratory.

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References and Related Publications

Contacts and Acknowledgments

Dr. Ken McGwire 
Desert Research Institute 
School of Engineering 
PO Box 2039 
Merced, California 95344

Acknowledgments: 

This research was supported by NSF OPP grants 0637004, 0230149, and 0440817.

Document Information

Document Creation Date

23 April 2009

No technical references available for this data set.
No FAQs or How Tos available for this data set.

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