Public safety UAS pilot reported an NMAC with an uninvolved helicopter during a public safety flight. No evasive action was taken.

Narrative

While operating the M300 during a structure fire as part of the City Office of Emergency Management; a helicopter flew by the fire scene at a very low altitude. At the time the sUAS was ~ 180' AGL and the helicopter passed by heading west at an altitude of 150' (barometric). The helicopter was ~ 175' horizontally from the sUAS. This placed this as a near miss with 30' elevation separation and 175' horizontal separation. I used ADS Exchange (website) to collect and analyze the helicopter flight path and obtained the flight path of the sUAS from its flight logs.The sUAS was flying under Part 107 regulations at the time and was in Visual Line of Sight. The sUAS was hovering at the time. The helicopter speed from ADS Exchange was listed as 90 knots. While our agency does possess a Blanket COA (Certificate of Authorization); we were not operating under it at the time since we did not need the ability to operate over people or moving vehicles. Anti-collision lights were activated and functional at the time and are located on the top of the sUAS. The sUAS also possesses other lighting for orientation and positioning. The sUAS did not take any action to avoid a collision as the helicopter came by so low and quick; the RPIC did not have enough time to react. There was not a Visual Observer as part of the Flight Crew assigned.