Projects

Digital Optical Imaging of Ice Cores for Curation and Scientific Applications

PI: Ken McGwire

Keywords: glaciology, climate, images, photos, scanning, ice, Greenland, Antarctic, Arctic, warming

This project has been developing novel methods for digital image analysis of glacial ice cores that are stored at the National Ice Core Laboratory (NICL) in Denver, Colorado. Imaging hardware and software techniques have been developed to meet specific needs in the scientific analysis of cores.

The NICL Optical Scanning System

The scanning camera operates on the core processing line within the NICL cold-room facility (-25?C) is capable of scanning a typical ice core with an approximate resolution of 0.025 millimeters. This linear scanning system (Figure 1) solves numerous problems that have been experienced with simple photography of cores such as parallax in images collected with a stationary lens viewing over many degrees and the difficulty of uniformly lighting an entire core at once. A touch-screen enabled front-end application was developed that allows the functions of the separate software packages for image scanning (ViewFinder, BetterLight, Inc.), the NICL inventory database (FileMaker Pro), image processing checks for image quality (Java-based image processing routines), and file management to be seamlessly integrated.

The IceImageJ Software This project has also created an image processing software system specifically for analyzing ice core data. The image processing tools and user interface are modifications of the ImageJ image processing software that was developed for the National Institutes of Health. The ImageJ structure has been enhanced with processing functions that are specific to ice core analysis. This includes methods of metadata and image file organization, allowing the user to easily browse through the thousands of images that may be acquired for multiple ice core projects. Examples of functions that specifically address the characteristics of ice core imagery include automatic mapping of fractured ice in images. This mask is used to screen "bad" areas out in other image processing routines (Figure 2).

Figure 2: Automated fractured ice mapping function

Other feature extraction capabilities include methods for calculating the angle of ice layer inclination in the image and a melt-layer finder that automatically scans ice images for fine-scale melt features. An annotation tool (Figure 3) provides an efficient mechanism for sharing information among scientists. Image processing functions are tightly integrated with the annotation capabilities, so that a user can manually choose annotation features from the image, or plot a brightness profile of the ice in a separate window.

Figure 3: Integrated annotation environment

Acknowledgements
Funding for this project was provided through a grant from the Office of Polar Programs of the National Science Foundation (NSF Grant OPP-0230149) in order to support the existing efforts of the staff at the U.S. Geological Survey's National Ice Core Laboratory in Denver, Colorado (http://nicl.usgs.gov/). This effort is also supported through collaborative efforts with Dr. Richard Alley of Pennsylvania State University.

Personnel
Kenneth McGwire (DRI)
Kendrick Taylor (DRI)
Richard Alley (PSU)
Geoffrey Hargreaves (USGS NICL)