A growing number of innovative operational and research EO satellite missions need reference measurements from ground for their validation. Luckily this correlates with an increasing number of ground-based/airborne/ship-borne mobile lidars available for field-deployment.

Airborne campaigns allow along-track underflights of overpassing satellites, mimicking the observing geometry, and in some cases even the payload specifications (i.e., airborne demonstrators), often accompanied by complementary active, passive and in-situ sensors providing contextual scientific information.

Especially atmospheric remote sensing lidar missions, such as Calipso, Aeolus and EarthCARE, benefit from direct validation through ground based HSRL systems. Apart from continues correlative data provided from ground-based lidar networks, mobile systems can be deployed in positions favorable in terms collocation criteria within field campaigns.

Space Agencies (ESA, NASA) with scientific and engineering partners, have recently developed and operated ground based reference lidars in the context of large joint international field campaigns, and airborne & ground based campaign roadmaps point towards exciting years ahead.