Campaign using surface reflectance data to support validation of Earth observation products

14 Jul 2022

Scientists from around the world are set to take part in a drone monitoring campaign and inter-comparison exercise that will deliver surface reflectance data to support the validation of Earth observation products.

Part of the Surface Reflectance Intercomparison Exercise for Vegetation (SRIX4VEG), the campaign will take place from 18 to 22 July at the Las Tiesas experimental farm, just outside the village of Barrax in the east of Spain.

SRIX4VEG is an element of the Fiducial Reference Measurements for Vegetation (FRM4VEG) project, which sets out to develop the protocols and procedures to validate products delivered by Copernicus Sentinel-2, Sentinel-3, and PROBA-V.

Hyperspectral information delivered by remotely controlled aircraft is expected to become a major source of surface reflectance validation data in the future, but there is currently no established protocol for gathering these data.

To address this challenge, ESA is collaborating with the international remote sensing community to develop guidelines for the collection of surface reflectance validation data by drones.

SRIX4VEG kicked off in March with a first workshop to introduce the project team, get to know the participating international teams, set out the details of the project, and provide clarifications.

SRIX4Veg
The SRIX4VEG project


Next week, participants will travel to Las Tiesas to complete a series of experiments in which drones are used to collect surface reflectance data over the planned study area. The flights will be completed as part of a predetermined sequence to ensure the data collected are as comparable as possible.

In addition, differences obtained with respect to the results retrieved by flying the drones with different team-specific sequences will be pointed out.

By considering the variability in outputs from each experiment, the participants will work to develop a proposal for how a good-practice protocol might look. These recommendations will be discussed amongst the community of experts taking part in SRIX4VEG.

Later this year, the SRIX4VEG community will meet again to discuss the results of the project in detail at a second SRIX4VEG workshop.

SRIX4VEG is endorsed by the Committee on Earth Observation Satellites (CEOS) Working Group on Calibration and Validation (WGCV), funded by ESA, and run in cooperation with several international partners, including USGS, ASI, DLR, Geoscience Australia and CSIRO.