Reference dataset for comparison of cloud detection algorithms for Sentinel-2 imagery

Sentinel-2 cloud mask reference dataset generated and analyzed as part of Tarrio, K., Tang, X., Masek, J.G., Claverie, M., Ju, J., Qiu, S., Zhu, Z. and Woodcock, C.E., 2020. Comparison of cloud detection algorithms for Sentinel-2 imagery. Science of Remote Sensing, 2, p.100010. [https://www.sciencedirect.com/science/article/pii/S2666017220300092](https://www.sciencedirect.com/science/article/pii/S2666017220300092)

1. Reference masks

Algorithms:

Fmask 1.x

Fmask 2.x

Fmask 4.x

Tmask

Sen2Cor

MAJA

LaSRC

Locations:

South Africa (35JPM)

Senegal (28PDC)

Switzerland (32TLT)

France (31TCJ, 31TFJ)

Morocco (29RNQ)

Standardized legend:

Original algorithm outputs were standardized to the same categorical legend.

0 = clear land

1 = clear water

2 = cloud shadow

3 = snow/ice

4 = cloud

All reference masks processed to both 10m and 30m resolution, with the exception of Tmask, which is available only at a 30m resolution.

Mask naming convention:

All processed masks are named according to the following convention:
M<*resolution*><*S2 MGRS tile ID*><*YYYY*><*DOY*><*algorithm*>
e.g. **M30T28PDC2016351TMASK**

2. Interpreted sample points

Sample points were selected based on agreement among different map products. This record includes a shapefile with the final interpretations for each of the sampled sites. (See publication for additional information.)