He joined KNMI in 1987, as R&D engineer.

In his early years at KNMI he participated in sensor development and automated calibration procedures for meteorological sensors.
During his career focus shifted to remote sensing systems, adding innovations to KNMI’s weather radars, especialy in the area of clutter detection.
Moreover he was KNMI’s expert on lightning detection systems.
He was involved as projectleader in a major upgrade of the dutch weather radars and in a major upgrade of the KNMI lightning detection network.

Starting december 2019 Hans has retired from its KNMI duties.