Acoustic air data systems

A transmitter assembly for an acoustic air data system, comprising:

• a pole having a length longer than a maximum boundary layer thickness of a boundary layer flow on an aircraft of a predetermined cruise speed such that at least a distal end of the pole is configured to extend outwardly from an aircraft surface to be at least partially outside of the boundary layer flow;
• and
• a transmitter disposed on or in the pole at or near the distal end of the pole such that the transmitter is located at least partially outside of the boundary layer flow when in use, wherein the transmitter is configured to output a transmitter signal, wherein the length of the pole is between about 1 inch and about 5 inches.

A method for determining air data, comprising:

• transmitting a transmitter signal outside of a boundary layer flow in a flow field into the boundary layer flow to be received by one or more receivers within the boundary layer flow wherein the transmitter is disposed on or in a pole having a length longer than a maximum boundary layer thickness of a boundary layer flow on an aircraft of a predetermined cruise speed such that at least a distal end of the pole is configured to extend outwardly from an aircraft surface to be at least partially outside of the boundary layer flow, wherein the length of the pole is between about 1 inch and about 5 inches.