The PDM³ can be used for general structural monitoring to assess the dynamic performance of structures (bridges or other) under vehicle or environmental loading conditions. The PDM³ provides an accessible and low-cost alternative to expensive total station systems. Structural monitoring with the PDM³ can be performed as follows:

• frequencies vary from 1Hz to 1000 Hz

• Simultaneous monitoring of up to 32 targets

• movements detected in 2-dimensions, with a scanned area of 3m x 1.7m at a stand-off distance of 20m, or 7.5m x 4.2m at a stand-off distance of 250m

• disposable reflective stick-on targets of 20mm diameter at 20m and 50mm diameter at 50m

• measurements with stand-off distances greater than 50m likely but not validated

• measurement of targets at up to 55 degrees from perpendicular (especially for monitoring of river spans)

• accuracy of approximately 4.0E-4 degrees or 7.2E-6 rad, which equate to +/-0.14mm at 20m

• (future) networking of up to 20 units in parallel

The results can be used to evaluate :

• Evaluation of structure deformation

• Structural health monitoring programs

• Prolonging structure life

• Structural stiffness evaluation

• Structure frequency analysis