Fiducial Reference Measurements (FRM) are a suite of independent, fully characterized, and traceable ground measurements that follow the guidelines outlined by the GEO/CEOS Quality Assurance framework for Earth Observation (QA4EO). These FRM provide the maximum Return On Investment (ROI) for a satellite mission by delivering, to users, the required confidence in data products, in the form of independent validation results and satellite measurement uncertainty estimation, over the entire end-to-end duration of a satellite mission. Within this context, the SPPA team manages a series of projects targeting the validation of ESA altimetry, atmosphere, land, and ocean products.
Long, uninterrupted, well-maintained, homogeneously calibrated time-series of ground-based remote sensing atmospheric ozone measurements have been and still are the backbone for the validation of ozone columns measured from satellite (Brewer-Dobson-Networks). There are no comparable networks for other satellite-derived trace gas measurements (e.g. NO2, HCHO). The Pandonia Global Network (PGN) is a collaborative effort between ESA and NASA with the aim to close this gap by providing fiducial reference measurements for satellite validation and air quality monitoring. The main instrument of the PGN is the Pandora and Pandora-2S spectrometer system. The APC group is collaborating with LuftBlick, the company designated to be in charge for the calibration, operation and scientific development of the PGN.