Utilizing Data Sets from the CReSIS Data Archives to Visualize Greenland Echograms Information in Google Earth 2012 Research Experience for Undergraduates in Ocean, Marine, and Polar Science

Team Members 2 of 26 Shaquia Johnson Mississippi Valley State University Maya Smith Winston-Salem State University Mentor: Mr. Jeff Wood

Abstract Since 1993, the Center for Remote Sensing of Ice Sheets (CReSIS) has been gathering ice thickness data in Greenland. This information is in various formats such as: Postscript Document Format (PDF), Joint Photographer Expert Group (JPEG), Keyhole Markup Language (KML), and Comma Separated Values (CSV). These formats display data in individual visualizations while another format; Matrix Laboratory (MATLAB) will display multiple sources of data, but in the proprietary software application only. The goal of this project was to combine the non-MATLAB visualizations into one window utilizing the PHP Hypertext Preprocessor scripting language and Google Earth. These product files would be simple in their construction, easily adaptable to new data formats, and provide continued display of newly acquired data. The PHP Hypertext Preprocessor language was used to modify the Keyhole Markup Language files to add description tags in order to display data from other formats. The combined files were displayed in the geographical program Google Earth available as a free download to users. 3 of 26

Introduction CReSIS Partners 4 of 26

Types of Data Accumulation Radar KU-band Radar altimeter Radar depth sounder Snow radar 5 of 26

Data Visualization KML CSV JPEG MatLab PolarGrid GIS Server 6 of 26

Scripting Languages Overview PHP JavaScript PHP XML DOM 7 of 26

PHP Overview Uses Platform Dreamweaver 8 of 26

XML Overview Structure 9 of 26

XML DOM Overview Tree structure 10 of 26 Root Node Parent Node & Attribute Node Child Node Sub-Child Node 20 Sub-Child Node 6 Sub-Child Node 14 End Child Node End of Parent Node End of Root Node

Google Earth Overview Visualization 11 of 26

KML Overview Structure Project KML 12 of 26

Data Location Overview Excel 13 of 26 Radar Depth Sounder Accumulation CSV KML JPEG MatLab Flight Date Number

Function Output_file Read the file Ensures browser has the mime type Opens file in proper application Modification- kml, Google Earth 14 of 26

Importing Echogram URLs Open text file URL -> Array Close text file 15 of 26

Retrieve CReSIS KML file file_get_contents 16 of 26

tempKMLflight Open tempKMLflight.kml Flight path data -> temporary file Close temporary file 17 of 26

DOM Set-up New DOMDocument Load temporary file Locate First Node (Root) Locate all "Placemark" elements Count Placemarks 18 of 26

Modifying File Structure Begin loop of Placemarks 19 of 26

Modifying File Structure Build value for description Joining PHP variable and HTML code Echogram URL + Hyperlink + Image Source Create new element 20 of 26

Save and Download File Save tempKMLflight.kml Call output_file function Pass file name, path, mime 21 of 26

Example of Operation /research.html 22 of 26

Results File combination in KML Simple combination script XML DOM 23 of 26

Conclusion PHP XML DOM Data Organization 24 of 26

Future Work Migrate code to Google Maps Work with CReSIS on data organization Add other data files Add older KML files (points vs. segments) Rewrite PHP code 25 of 26

QUESTIONS? Questions?