Apparatus for on-site mounting of surveying instruments

Apparatus securing a surveying instrument to an existing rigid, stable structure on a job site without a tripod, the apparatus comprising:

• an arm assembly, the arm assembly including an elongated rigid member defining a longitudinal axis and first and second opposing ends defining a length;
• a mounting mechanism attached to one of the opposing first and second ends of the arm assembly, the mounting mechanism being adapted to removably receive and secure a surveying instrument to the arm assembly;
• wherein the mounting mechanism defines an instrument mounting axis, and wherein the instrument mounts to the mechanism with the axis being substantially perpendicular to the longitudinal axis of the elongated rigid member;
• at least two clamps, each clamp having first and second portions, wherein the first portion of each clamp includes an adjustable jaw configured to tighten each clamp onto a different respective position along the elongated rigid member;
• wherein the second portion of each clamp includes a device enabling the clamp to be rigidly fastened to an existing structure on a job site;
• wherein the clamps secure the elongated rigid member in a horizontal orientation with the mounting mechanism facing upwardly to receive and secure the surveying instrument to the arm assembly;
• and
• wherein the surveying instrument is a total station, theodolite, laser or laser target.