Early burst
An early burst occurs if the fuze, set to the proximity role, initiates the shell beyond the position in the trajectory where proximity arming is complete, but before the intended burst height.
A malfunction in which the munition functions after the arming delay but before sensing the designed functional stimulus from either target or command. For proximity fuzes, following safe separation, an explosion prior to the design height of burst environment is considered to be an early burst.
Ministry of Defence. (2015, May 20). Defence ranges safety (JSP 403, volume 4)
NATO. (April 2002). Allied Ordnance Publication-38 (Edition 3/édition 3). (n.d.) Retrieved from https://www.techstreet.com/standards/nato-aop-38?product_id=1983679