This interesting article was in Sundays' Demgaz.

PEA RIDGE -- Archaeologists are using remote sensing devices to locate cannon shell fragments and other metal objects underground at Pea Ridge National Military Park.

They hope the technology will give them a better idea of where the battle lines were drawn in Benjamin Ruddick's cornfield, where heavy fighting took place during the Civil War.

"We're attempting to make a density map of the fighting across this landscape," said Jami Lockhart, director of remote sensing for the Arkansas Archeological Survey in Fayetteville.

"What we hope to do is find concentrations of metal that might indicate where the battle lines were and exactly where the battle took place."

The study began last week and will continue for four years, said Jamie Brandons research station archaeologist with the Arkansas Archeological Survey.

The full article is here: http://www.arkansasonline.com/news/2015/dec/06/technology-to-help-pinpoint-1862-pea-ri/?f=news-arkansas