Most pictures of airliner's nose sections show small dark tube- or fin-shaped instruments sticking out of the fuselage below the cockpit windows.
For example this Airbus A350 shows them well: Source: Airliners.net
Other airliners (737, A380, 787) carry similar instruments at the front.
I'm sure Google would be able to tell me if only I knew how to correctly phrase my question, but...
These instruments sticking out of the fuselage, what purpose do they serve?