Intercomparison exercise for surface reflectance fiducial measurements for vegetation to test user-based differences in surface reflectance fiducial reference measurements (FRM) used for validation of current SR satellite products;and to ensure consensus on global SR validation protocols.
There is a growing interest in UAV-based optical sensors for SR Cal/Val; •UAV provide flexible and cost-effective solution for SR Cal/Val: cover greater areas, survey of inaccessible sites, complement in-situ infrastructure, enhanced spatial sampling. •However, protocols around this are yet to be developed and lots of people are developing different procedures. SRIX4VEG Contribute towards defining global community-agreed guidelines, protocols and procedures for UAV-based SR product validation. A campaign took place in Spain, Barrax in July 2022 with the participation of 7 teams from EU, Canada, US with 52 UAV flights in total with different UAV-based hyper- and multi-spectral sensors in VNIR/SWIR range including ground based measurements (ASD FieldSpec, reflectance panels, GPS base station, Microtops for AOT). •Round-robin were organised where each participant flew back-to-back with every other in turn, common flight plan, pairwise comparison. The Processing UAV data on-going; after gathering the results, comparison over integrated spectral bands matching S2 will be undertaken. Variability among results will be analysed and discussed in a WS planned in Q1 2023. Inter-comparison results will be published in a peer-reviewed journal (Q2 2023) and finally best practices protocol for UAV-based SR product validation will be prepared and agreed; first version expected in Q2 2023 for endorsement by CEOS. A complementary exercise will be organised in Australia in Q1 or Q2 2022.
Delta campaign will be organised in Australia in Q1/Q2 2023. Workshop will follow in Q2/Q3 2023 together with a publication with the results and updated protocols
Second workshop for SRIX4Veg was held in November 2023 at ESA-ESRIN. SRIX4Veg-II will conduct a round-robin exercise in Calperum Research Station, an CEOS WGCV LPV supersite in Australia in the week of 11-15 March 2024. It will build on the findings from SRIX4Veg-I and extend the exercise to a more complex vegetation cover. Deliverable needs to be extended to 12/31/2024.
First workshop in 2021; campaign was done in July 2022; additional campaign will take place in Australia in Q1/Q2 2022. Final Surface Reflectance protocols should be provided by Q3/Q4 2023.