Definition

A TRIANGULATION SIGNAL consist­ing of two separate struc­tures, independent of one another an inner structure which supports the THEODO­LITE and sometimes the TARGET or SIGNAL LAMP, and an outer structure which supports the observer and his assist­ants and sometimes the TARGET or SIGNAL LAMP. Triangu­lation towers are used to elevate the LINE OF SIGHT above trees, topographic features, and other obstacles that might interfere with the OBSERVATIONS. See BILBY STEEL TOWER.