Definitely sounds like G-TOPS with the FLI-MAP LiDAR system (see
G-TOPS with FLI-MAP).
By the way, those saucers on the outriggers have dual frequency GPS antennas mounted on them, which collect co-oridnate locations of the aircraft during the flight/the capture of the LiDAR survey data.
The co-ordinates are time-stamped at the time they get logged and then used together with the actual LiDAR (Laser) measurements during post-flight processing to form a 3-D topographical model, which eventually then leads to high accuracy topographical mapping of the surveyed area (see
FLI-MAP Website).