The Marine Corps wants an inexpensive cheap thermal imaging system that can detect the location of hostile fire.
Current acoustic detection methods are hampered by urban and mountainous terrain, as is muzzle flash detection. Projectiles strongly emit infrared energy, but some thermal imagers are only capable of reliably detecting slow objects like grenades, while other imagers are expensive and power-hungry, according to the Navy research solicitation.
So, the Marines want a body-mounted thermal imaging system with a 70-percent probability of detecting hostile fire during day or night. Accuracy in determining the bullet's point of origin should be less than five degrees of error in azimuth, and less than 20 percent in range.
The system should "be capable of acquiring and temporarily storing (for at least 15 minutes) the tracks of multiple weapons firing near-simultaneously, including those operating at a high rate of fire (up to 2,000 rounds per minute)," according to the proposal.