# Remote Sensing for Precision Agriculture: Sentinel-2 Improved Features and Applications
## 2 Remote Sensing for Agriculture
### Sentinel-2 Spatial and Temporal Resolutions Compared to Other Satellites  
Sentinel-2 has had two launches, Sentinel-2A that was launched on 23 June 2015 and Sentinel-2B on 7 March 2017, forming, up from this date, the Sentinel-2 A + B constellation ([[https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/sentinel-2](https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/sentinel-2)]([https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/sentinel-2](https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/sentinel-2))). Both have a 7.25-year lifetime, including a 3 months commissioning phase with adequate propellant for up to 12 years. Both Sentinel-2A and Sentinel-2B satellites have on board the exact same MultiSpectral Instrument (MSI) with bands from the visible to the shortwave infrared: four (4) bands at 10 m, the classical broadband visible blue (490 nm), green (560 nm), red (665 nm), and near infrared (842 nm); six bands at 20 m, four narrow bands in the vegetation red edge spectral domain (705, 740, 775, and 865 nm), and two longer SWIR bands (1610 and 2190 nm); and three (3) bands at 60 m dedicated to atmospheric correction (443 nm for aerosols and 940 nm for water vapor) and to cirrus detection (1380 nm) (Table 1). After the second launch the satellite provides higher temporal resolution with a 5-day global revisit frequency, and up to 2-day revisit in top northern and southern parts of the globe. Satellite spatial and temporal resolutions depend on their type of orbit and their orbit altitude. Most of the satellites are two types: polar orbiting which are sun synchronous and have orbits that cross near the poles in low earth orbit (around 700 km); or are geostationary geosynchronous and orbit above the equator, located much farther distance from the earth (35,000 km). In this case Sentinel-2 is sun synchronous and has a systematic coverage of all land surfaces (including croplands) globally from \(-56^{\circ}\) (Southern America) to \(+83^{\circ}\) (Northern Greenland) latitude, with a swath width of 290 km [28] and an earth orbit of 786 km. Focusing on spatial and temporal resolution, in Figure 1 various satellites are shown in comparison to the most recently launch satellite of interest to precision agriculture--Sentinel-2. For comparison, the MODIS (Moderate Resolution Imaging Spectroradiometer) and Proba-V, with spatial resolutions ranging from 150 to 500 m and both with a daily revisit time can monitor agricultural systems at the agroecosystem level. Meanwhile, the IRS AWiFS and Landsat 8 satellites have a spatial resolution of 30-100 m and a revisit time of 24 and 16 days, respectively. In this case, both agroecosystems and plant communities at local to regional scales, namely the crop field level, can be monitored. On the other hand, both the SPOT (Satellite Pour l'Observation de la Terre) 6/7 have similarities with Sentinel-2 A + B as both are constellations of two satellites and therefore the combined revisit time is reduced, which translates in providing global daily imagery in the case of SPOT and every 5 days in the case \begin{table}
\begin{tabular}{c c c c} \hline \hline
**MSI Band** & **Spatial Resolution (m)** & **Central Wavelength (nm)** & **Bandwidth (nm)** \\ \hline B1: Coastal Aerosol & 60 & 443 & 20 \\ B2: Blue & 10 & 490 & 65 \\ B3: Green & 10 & 560 & 35 \\ B4: Red & 10 & 665 & 30 \\ B5: Red-Edge & 20 & 705 & 15 \\ B6: Red-Edge & 20 & 740 & 15 \\ B7: Red-Edge & 20 & 783 & 20 \\ B8: NIR & 10 & 842 & 115 \\ BSA: Vegetation RE & 20 & 865 & 20 \\ B9: Water Vapor & 60 & 945 & 20 \\ B10: SWIR Cirrus & 60 & 1375 & 30 \\ B11: SWIR & 20 & 1610 & 90 \\ B12: SWIR & 20 & 2190 & 180 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Bands and resolutions of Sentinel-2 MultiSpectral Instrument (MSI) [28; 29]. of Sentinel-2.