Acoustic wind measurement

A wind measurement apparatus comprising:

• a frame assembly;
• four transducers mounted to the frame assembly such that their respective locations serve as respective vertices of a regular tetrahedron;
• and
• a reflector assembly mounted to the frame assembly such that it is positioned substantially at a center of said regular tetrahedron at a distance from the transducers to allow for an airflow between the reflector assembly and each of the transducers, wherein the reflector assembly comprises a reflector element provided as a solid that has eight vertices and six substantially identical concave faces that serve as respective reflector surfaces and that is oriented with respect to said transducers such that each transducer is facing a respective vertex of the reflector element,
• wherein each transducer is arranged to:
• transmit a respective measurement signal in a respective transmitter beam, TX beam, towards the reflector assembly such that the respective TX beam meets the three reflector surfaces that meet at the vertex of the reflector element faced by the respective transducer, and
• receive, via said three reflector surfaces, respective partial reflections of respective TX beams originating from other ones of said transducers.