Air traffic safety electronics personnel (ATSEP) is an International Civil Aviation Organization term for the electronic engineers involved with the creation and support of the ground-based electronic hardware and software systems used to support air navigation and air traffic management. In India they were known as CNSO. Airports Authority officers association India started celebrating CNSO day from 25 November 2013 later on from November 12, 2015, it started celebrated as ATSEP day. The association started first ever commemoration of ATSEP (CNSO) is now known as ATSEPA(l).