The RIEGL^® VQ-840-GL is a fully integrated, compact airborne laser scanner for combined topographic and bathymetric surveying. The proven form factor and the use of very lightweight material enable a reduced weight of less than 10 kg (22 lbs), making the VQ-840-GL suitable for integration into crewed aircraft and UAVs.

The scanner carries out laser range measurements for high resolution surveying of underwater topography with a narrow, visible green laser beam, emitted from a pulsed laser source. Subject to clarity, at this particular wavelength the laser beam penetrates water enabling measurement of submerged targets.
The distance measurement is based on the time-of-flight measurement with very short laser pulses and subsequent echo digitization and online waveform processing. To handle target situations with most complex multiple echo signals, beside the online waveform processing the digitized echo waveforms can be stored on the removable data storage card for subsequent off-line full waveform analysis.
The laser beam is deflected in an elliptic scan pattern and hits the water surface at an incidence angle with low variation.
The VQ-840-GL can be complemented with an inertial navigation sensor for subsequent estimation of the instrument's location and orientation. As a further option a high-resolution digital camera can be integrated.
The rugged internal mechanical structure together with the dust- and splash water proof housing enables long-term operation on airborne platforms.