5.2.7.3 Video latency

One critical parameter is the time delay between the occurrence of an event in the real world and its presentation to the ATCO/AFISO on the visual presentation/binocular functionality, referred to as video latency. The maximum allowable video latency, including its variation in time, should be determined by the local safety assessment, with the aim of not negatively affecting the ATCO’s/AFISO’s ability to safely provide ATS. It is recommended that this value is as low and constant as possible, as long delays will undoubtedly negatively affect the ATCO’s/AFISO’s situational awareness, with a direct safety impact. The exact figure should be derived from operational needs, taking into account the local conditions of the operational context. Recommendations for maximum video latency are presented in the notes below; however, subject to the outcome of the local safety assessment and the acceptance by the competent authority, an alternative maximum video latency may be applied. Note: EUROCAE ED-240A Change 1 [19] (VC REQ 01) stipulates a maximum video latency of 1 second, as this ‘is related to existing ground surveillance sensor standards and is considered as reasonable in a Remote Tower environment’. Note: Validation activities performed in the framework of SESAR JU programme have indicated a recommended maximum video latency of 1 second (refer to SESAR OSED [24] (REQ-06.09.03-OSED-VC03.1105) & SESAR Technical Specification [25] (REQ-12.04.07-TS-0110.0007)); however, this should be seen in the context of the specific conditions (operational and technical) that were validated and hence may not be universally fit for purpose.