A high-accuracy non-contact optomechanical system has been designed for measuring the surface profile of relatively flat and large objects. The experimental set-up consists of a motorized gantry, a rangefinder, a CCD chip and a laser diode. This set-up permits discrete measurements to be performed on objects with a maximum plane surface area of 2.6 × 0.5 m2 along both the X and Y axes. Experiments were carried out on carbon sandwich panels. An uncertainty of ±8 µm has been obtained on flat and smooth surfaces; a ±30 µm uncertainty has been determined for a rough carbon sandwich panel.