Attacks on bases in Iraq and Afghanistan have the U.S. Army and Marine Corps reviewing and revising some of their base defense systems. The Army is particularly vexed by hit-and-run mortar fire in an urban environment and the problem has been compounded by the fact that many artillery units in Iraq are tasked with border security and other jobs that take away from their counter-fire duties. To date, eight percent of  U.S. combat deaths in Iraq have come from mortar fire. 

The Army has found that the AN/TPQ 37(V)3 Firefinder anti-artillery radar has some limitations in combat. The system was designed to cover a formation with a 90 degree arc of coverage, but attacks are coming in on a 360 degree basis. Firefinder doesnt work so go against a [pickup] truck that pulls up to an intersection, pops three rounds and then runs, or a mortar tube on the third floor of a building that pops three runs and goes back inside the building, said one official. An advanced radar, the AN/TPQ-47 Phoenix, is supposed to deal with some of the limitations of the Firefinder, but Phoenix wont be ready until 2008. The Army has fielded three to four lightweight counter-mortar radars deployed to Iraq and wants to boost that number to 25 by October, but the radars arent precise enough to deliver counter-battery fire in cities. Lifting radar platforms off the ground to reduce ground clutter obstructions from buildings and other urban terrain is another option being examined. 

Another tool the Army is looking at would allow troops to input digitized terrain data and friendly positions into a computer and then calculate likely positions where mortar or rocket-propelled grenade fire might come from. The computer tool would allow a sniper to cover threat areas protected by multiple radar sets; currently snipers only cover one radar arc. 

Meanwhile, the Marines would like to find a system to replace the short-range Stinger surface-to-air missile. Stinger was designed to attack high-speed jet aircraft but low-cost UAVs and cruise missiles are an evolving and more likely threats in future conflicts. The replacement system would also have a secondary role to engage lightly-armored vehicles, including truck and car bombs. The Marines would like to have a single launcher for both missions and to deploy an initial system by 2008 or 2008. Doug Mohney