As operations in Iraq and Afghanistan have demonstrated, the enemy is adept at making inexpensive improvised explosive devices, or IEDs, and modifying them over time to become even more lethal.
“For us to adapt to those threats, we must be able to identify and assess what those IEDs or weapons are and how they’re being used against us,” said Dr. Jay Ehrgott, a research engineer with the Engineer Research and Development Center, or ERDC, U.S. Army Corps of Engineers, Vicksburg, Mississippi. He spoke at the Pentagon on Lab Day, May 14.
To identify the threat in the past, experts from ERDC reaction teams or the Joint IED Defeat Organization, known as JIEDDO, traveled to the location to examine the craters left behind by improvised explosive devices or holes in vehicles made by projectiles. The forensics work, incidentally, is termed CALDERA+, which stands for Crater Algorithm Design for Explosive Charge Analysis.
However, when doing forensic weapons signature research, time is of the essence. Soldiers on-site where or near when the event occurred, would have a much better chance of getting evidence before it becomes contaminated by weather or human activity. Ehrgott compared the task to “CSI,” or crime scene investigations.
So, ERDC, in collaboration with JIEDDO, the Army Research Lab and National Ground Intelligence Center, came up with a plan to provide training and equipment to frontline Soldiers — particularly explosives ordnance personnel — to do the forensics.
ERDC published a “Post-Blast Crater Collection and Analysis Guide” that offers easy-to-understand techniques to expedite crater analysis. A three-day training course fortifies the guide.
The training includes taking measurements and photos of the crater’s geometry, as well as obtaining and analyzing soil samples. The way it’s done is standardized so that the data are valid, reliable and results can be replicated for later testing in the lab, Ehrgott said.
When ERDC receives the data, engineers can deconstruct the so-called scene of the crime and determine the type of weapon or IED used and the power of them, he said.
For example, some IEDs are made up of artillery shells, some are made with common ingredients like fertilizer, some are explosively formed projectiles which focus energy on the underbelly of vehicles, and dirty bombs might include a substance like chlorine with the blast material.
Over time, ERDC and its collaborating partners have amassed a database of threats by type, time and location. The database has informed commanders of the evolving threats, Ehrgott said.
With this knowledge, commanders can “adjust mission planning, improve tactics, techniques and procedures and evaluate effects on our protective systems,” he said.
In addition to crater analysis, Soldiers are trained to identify enemy projectiles by examining the characteristics of holes to armor and vehicles, he said. Each weapon used produces a distinct signature or fingerprint.
ERDC’s lab fires a variety of rounds at test plates to produce a template library of signatures.
Finally, measurements of the chemical and metallurgic properties of the projectile where it penetrated the material are taken to cross-validate the identity of the weapon used, he said.
All of this research and fieldwork has attracted the attention and interest of other agencies.
In addition to the Army; the other services, law-enforcement agencies across the country and investigation units, like the Bureau of Alcohol, Tobacco and Firearms, are incorporating most of the post-blast collection and analysis techniques into their training curriculum, Ehrgott said.
Source: US Army