The intelligence community wants to put biometric identification technology on drones but has hit a wall when it comes to the most widely used biometric: facial recognition.

Federal programs experimenting with facial recognition technology have found the reliability depends greatly on lighting, camera position and other environmental factors—elements that are almost impossible to control at long range. But improvements in computer vision and techniques that take a subject's entire body into account are increasing the possibilities.

The Intelligence Advanced Research Projects Activity, or IARPA, issued a broad agency announcement solicitation for its latest attempt to improve biometrics at range, the Biometric Recognition and Identification at Altitude and Range, or BRIAR, program.

"The BRIAR program aims to develop software algorithm-based systems capable of performing whole-body biometric identification at long-range and from elevated platforms," the call states, outlining a three-phase process to prototype and test novel ways to incorporate multiple biometric signatures—such as face, gait and body type—to improve identification and verification at long ranges and steep angles.