There was an interesting documentry on Satelite channels about the night the Titanic sank and the weather/atmospheric and sea conditions. The sea was flat calm (some of the ships crew said in many years it was calmst they had ever seen) with the change in sea temp in the Labrador current it caused a crystal clear night and a mirage effect. this caused 2 issues the ships crew couldn't distinguish sea surface and horizon making identification of the Iceberg near impossible till it was right on top of them. And the Californian couldn't properley identify Titanic due to the optical distortion. The mirage even masked morse signal lamp.
As to the Radio operator being asleep it wasn't a requirement to have the radio manned 24/7 until after the Titanic sank.
_________________ "There was nothing wrong with Titanic when she left the Shipyard" Tim McGarry Belfast Comedian