# Remote Sensing for Precision Agriculture: Sentinel-2 Improved Features and Applications
## 2 Remote Sensing for Agriculture
### Satellites and Remote Sensing Scales of Observation  
Over the last 50 years of digital evolution, numerous satellites with multispectral sensors have been launched to orbit around the Earth for the purpose of environmental and agricultural remote sensing. Currently, one of the most relevant Earth observation programs focused on detection and assessment of vegetation is Copernicus. The Copernicus Program, led by the ESA, is a program aimed to increase the satellite-based Earth observation capacities and within which Sentinel-2 twin platforms were launched. Besides the multispectral Sentinel-2 system, various satellites have been launched or are planned to be launched as part of this still on-going program. Regarding potential agricultural applications within the Copernicus program, it is worth mentioning Sentinel-1 ([[https://sentinel.esa.int/web/sentinel/missions/sentinel-1](https://sentinel.esa.int/web/sentinel/missions/sentinel-1)]([https://sentinel.esa.int/web/sentinel/missions/sentinel-1](https://sentinel.esa.int/web/sentinel/missions/sentinel-1))) that carries a synthetic-aperture radar on board as well as Sentinel-3 that provides thermal data at 1 km of spatial resolution ([[https://sentinel.esa.int/web/sentinel/missions/sentinel-3](https://sentinel.esa.int/web/sentinel/missions/sentinel-3)]([https://sentinel.esa.int/web/sentinel/missions/sentinel-3](https://sentinel.esa.int/web/sentinel/missions/sentinel-3))).  
Framing the concepts regarding satellites features is especially relevant in order to grasp Sentinel-2 improvements compared to other orbiting satellites. In this sense, it is central to understand first satellite resolution and observation scales as they determine satellite systems' agricultural monitoring capacities.  
Regarding resolution, four parameters are central to approach a better understanding of the aims and scope of these instruments. First, the spectral resolution, namely the number, width, and location on the electromagnetic spectrum of spectral bands in the sensor system. Second, the spatial resolution, which is the measure of the smallest object that can be resolved by the sensor, e.g., pixel size. Third, one must consider the temporal resolution which is a measure of the frequency with which a sensor revisits the same area of the Earth's surface; and finally, the radiometric resolution, which is determined by the number of bits into which the recorded radiation is divided [26] and determines the spectral precision of the measurements.  
Following [PERSON] et al. [27], on the matching of ecological, agricultural, and remote sensing scales, we currently find that on the basis of individual plants, plant communities, and agroecosystems, different remote sensing technologies may provide coverage across canopy and landscape scales. Furthermore, it provides coverage across a range of plant physiological processes from evapotranspiration and photosynthesis to phenology dynamics, productivity, and even quality traits such as those of a crop's harvestable component nutritional value. The spatial, temporal, and spectral resolutions of any sensor-satellite system are central to determining the scale at which an instrument can monitor crops, and therefore the most adequate approach towards guiding agricultural monitoring and assessments and subsequently management actions.