Specification: The Header Service shall begin to write the header file(s) immediately after receiving the end-of-telemetry Event from the Camera Control System and, when complete, emit one or more LargeFileObjectAvailable Events that will notify the EFD of the existence of the new header file(s).

Discussion: The Event anouncing that a Large File Object (LFO) is available will contain the image name, a unique id that will be used to match images (pixels) from the DAQ with the header meta-data.