*2.3. Satellite Imagery*

Sentinel-1 is part of the European Copernicus program for Earth observation. The payload of the two Sentinel-1 satellites includes a dual-polarization (VV and VH) C-band SAR instrument that is an active phased array antenna working at 5.405 GHz frequency (corresponding wavelength 5.55 cm). The resolution of the Level-1 Ground Range Detected (GRD) Interferometric Wide (IW) mode that was used in this study is 20 × 22 m, with a

pixel size of 10 × 10 m, swath width of 250 km, and a revisit time of six days for images with the same geometry. Sentinel-1A and Sentinel-1B were launched on 3 April 2014 and on 25 April 2016, respectively. The Sentinel-1 incidence angle in the IW mode ranges approximately between 29◦ and 46◦. Figure 2 shows the graphical representation of the local incidence angle. In this study, some sites were close to the edge of the images, resulting in an incidence angle range from 30.8◦ to 45.8◦, and in local incidence angle values from 30.3◦ to 47.7◦ (Figure 3). Therefore, this study was based on a wide range of incidence angles. The areas within SAR imagery used in the present study are not affected by adverse geometrical effects, such as radar shadow, foreshortening, and layover. The SAR imagery used in this study was downloaded from the ESA Copernicus site (https://scihub.copernicus.eu/dhus/#/home, accessed on 23 June 2021). Overall, 38 SAR images were used to derive models for wheat (Table S1), 19 for cotton (Table S2), and 94 for processing tomatoes (Table S3), Figure 3).

**Figure 2.** Local incidence angle (θ). The local incidence angle (θ) is defined as the angle between the incidence radar beam and a line that is normal to the surface, considering local relief, typically derived from a DEM.

**Figure 3.** The number of SAR images acquired at different local incidence angles used in the modeling of different crops.
