Sorry, I misspoke about the angle of separation (it's actually 120 degrees) and did a poor job of describing the orientation. If you imagine a vector perpendicular to the sheet indicating the direction of travel, then these three vectors would intersect at a single point and lie along the surface of a cone. The angle between the axis of the cone and each vector, the azimuth, was 30 degrees.

https://i.ibb.co/VDgS8yr/3beam.png