This standard is devoted to providing radar definitions. The standard includes terms formerly found in IEEE Std 172™-1971 [B4] and IEEE Std 172-1983 [B5], with the exception of a few terms that are common in both fields and new and updated terms. IEEE Std 172 was withdrawn in 1993. As radar technology and literature evolve, new terms will be added, and obsolete terms deleted. This standard is published for the purpose of promoting clarity and consistency in the use of radar terminology. The definitions represent the consensus of a panel of radar experts. The purpose of the revision is to add new terms, revise others, and delete a number of obsolete terms that no longer appear in radar literature or usage. Revision Standard - Active. The promotion of clarity and consistency in the use of radar terminology is the purpose of the definitions provided in this guide. The consensus of a panel of radar experts is represented in the definitions herein.