Campaign information
Located approximately 10 km west of Albacete, near Barrax, Castilla-La-Mancha, Spain, Las Tiesas – Barrax (39.0549°N, 2.1010°W) is an experimental farm. The site is managed by the Instituto Técnico Agronómico Provincial (ITAP), and is comprised of irrigated crops including alfalfa, garlic, rapeseed, spring onion, sunflower, poppy and wheat), in addition to a number of bare soil areas.
For the biophysical variables, the Las Tiesas – Barrax campaign took place between 2nd and 8th June 2018. 52 elementary sampling units (ESUs) were characterised (52 with digital hemispherical photography, 45 with LI-COR LAI-2200 measurements, and 44 with Konica Minolta SPAD-502 chlorophyll meter measurements). These data were upscaled to produce high spatial resolution reference maps using Sentinel-2 data. For surface reflectance, a second campaign was conducted on 2nd August 2018. All datasets were collected and processed according to the FRM Protocols and Procedures and Validation Methodology. The FRM datasets produced from the campaign are available to download below.
Datasets
N.B. For V2, the biophysical in situ reference measurements were reprocessed to correct a bias in the LAI data. A bug in the computation of per-pixel uncertainties associated with the high spatial resolution reference maps was also corrected.
| Dataset | Description |
|---|---|
| Surface reflectance | |
| In situ reference measurements | In situ reference measurements of alfalfa and bare soil fields |
| Biophysical variables | |
| In situ reference measurements (V2) | In situ reference measurements (and uncertainties) at the elementary sampling unit (ESU) level |
| High spatial resolution reference maps (V2) | 20 m spatial resolution reference maps (with per-pixel uncertainties) derived by upscaling the in situ measurements using Sentinel-2 data |
Attribution
If using the FRM4VEG data in publications or reports, a link to the FRM4VEG website should be provided along with the following citations:
Surface reflectance
Origo, N., Gorroño, J., Ryder, J., Nightingale, J. and Bialek, A. 2020, Fiducial Reference Measurements for Validation of Sentinel-2 and PROBA-V surface reflectance products, Remote Sensing of Environment, 242, 111690, 10.1016/j.rse.2020.111690.
Biophysical variables
Brown, L.A., Camacho, F., García-Santos, V., Origo, N., Fuster, B., Morris, H., Pastor-Guzman, J., Sánchez-Zapero, J., Morrone, R., Ryder, J., Nightingale, J., Boccia, V. and Dash, J. 2021, Fiducial Reference Measurements for Vegetation Bio-Geophysical Variables: An End-to-End Uncertainty Evaluation Framework, Remote Sensing, 13 (16), 3194, 10.3390/rs13163194.
The following text should also be incorporated in the acknowledgements:
This study has been undertaken using data from the “Fiducial Reference Measurements for Vegetation – Phase 2” (FRM4VEG – Phase 2) project, which was funded by the European Space Agency.