Content By Randy Fratena and Charles Mitchell

By: Randy Fratena and Charles Mitchell

At the Harris Corp. (Government Communications Systems Division—GCSD), solid carbon-fiber and aluminum-shaped reflector dishes are manufactured to support military ground, sea, and air communications. These reflectors range in size from 1 to 13 m. To meet performance requirements, the surface profile of these reflectors are held to rigid tolerances. For 25 years, photogrammetry (PG) has been the Harris standard for characterizing the surface profile of these reflectors due to the technology’s high accuracy, portability, and ability to work in unstable conditions. The technique has been “tried and true” and is familiar to engineering and quality organizations.

During the past year, laser radar (LR) has been evolving into a robust inspection technique that reduces materials and automates the measurement process. In a cost-competitive market of reflector fabrication, laser radar offers a promising solution in reducing the recurring labor cost during significant production efforts. To implement this technology, it was necessary for the LR to be compared to what Harris recognizes to be the standard of surface characterization. To be accepted, the surface profile characterization (i.e., RMS) for reflectors must be less or equal to 10 percent when compared to photogrammetry.