stadia rod


stadia rod

[′stād·ē·ə ‚räd] (engineering) A graduated rod used with a stadia to measure the distance from the observation point to the rod by observation of the length of rod subtended by the distance between the stadia hairs.

stadia rod, stadia

A graduated rod used in the determination of distance by observing the intercept on the rod subtending a small known angle at the point of observation; the angle usually is defined by two fixed lines in the reticle of a telescope (transit or telescopic alidade).