Due to their complexity, DIAL LIDARs have only been provided to date as vertical pointing systems.
DIAL LIDARs are designed to be extremely sensitive - able to detect target gases even when they are present at just a few parts per billion (ppb). The DIAL technique involves comparing one wavelength of light which is strongly absorbed by target particles with one which is weakly absorbed. In this way, concentrations of the target gas can be established. This makes DIAL LIDAR relatively large and complex compared with other types of LIDAR system.