Microwave datum tool

A measurement system, comprising

• an electromagnetic imager adapted to generate images of an interior portion of a visibly opaque obstruction, said imager comprising a source coupled to a focusing element for focusing radiation directed to a proximal side of the obstruction into interior portion thereof and a detector for detecting at least a portion of the radiation propagating back from the obstruction, and
• a reflective focusing element disposed on a distal side of the obstruction for reflecting at least a portion of the radiation propagating through the obstruction,
• wherein said detector detects at least a portion of the radiation reflected by the reflective element for determining an alignment of said source relative to said reflective element.

A measurement system, comprising

• a source of radiation adapted to generate a radiation beam having at least one wavelength capable of penetrating a visibly opaque obstruction, said source being movably positioned on one side of the obstruction for illuminating thereof with said radiation beam, and
• at least two sensors positioned on another side of the obstruction such that each sensor detects at least a portion of radiation transmitted through the obstruction so as to determine a position of said source relative to a reference point on said obstruction.

A measurement method, comprising

• directing microwave radiation along a measurement path,
• determining attenuation of the radiation after at least one passage along said path, and
• estimating metal content along said path based on said attenuation.