## 3 Materials and Methods
### Satellite Imagery Sources for Remote Sensing of Study Areas  
There are numerous sources of satellite imagery that can be used for spaceborne remote sensing monitoring of agricultural areas and crop fields. The following are the most used for crop monitoring in this area, with free access for research purposes and have been used in our studies in this work:3.2.1. Landsat (National Aeronautics and Space Administration (NASA), Washington DC, USA; United States Geological Survey (USGS), Reston, VA, USA)  
Landsat is a joint program of NASA and USGS for acquisition of satellite imagery of the Earth. Landsat images are a good data source to detect land uses for regional studies for crop type classification and yield estimation, however, it has a relatively long revisit cycle (16 days), so it is often difficult to find a day with a cloudless image during the summer in the humid region of the Lower Northern Mississippi. For this study, Landsat 8 multispectral imagery with 30 m spatial resolution was collected from EarthExplorer for the products with a processing level of 2 for atmospherically corrected surface reflectance.  
3.2.2. Sentinel (European Space Agency (ESA), Paris, France)  
ESA has developed the Sentinel program for developing a series of next-generation Earth observation (EO) satellite missions to advance ongoing and upcoming EO studies. Images from Sentinel-2 [31; 32; 33; 34; 35; 36] and Landsat 8 [36] have already been used for agricultural remote sensing and crop monitoring for precision agriculture applications. With a shorter cycle of revisiting (less than 5 days) compared with Landsat, Sentinel-2 has a better chance to provide more cloudless images during the summer in humid regions. For this study, Sentinel 2A multispectral imagery with 10 m spatial resolution was collected from EarthExplorer for the products with a processing level of 1C, which includes radiometric and geometric corrections, along with orthorectification to generate highly accurate geolocated products.  
3.2.3. PlanetScope (Planet, San Francisco, CA, USA)  
Planet operates the PlanetScope, RapidEye, and SkySat Earth-imaging satellite constellations. Planet images have been increasingly used in crop field monitoring [37; 38; 39]. Planet provides imagery services for a fee. With the mission of the company to promote scientific research with rapid Earth surface observation, Planet offers university-affiliated students, faculty members, and researchers accounts in the Education and Research Program for limited, non-commercial access to PlanetScope imagery and RapidEye archive. Recently the US federal government made a contract with Planet for US federal scientists to similarly apply for accounts in the Education and Research Program for limited, non-commercial access to Planet imagery. For this study, PlanetScope 4-band multispectral imagery with 3 m spatial resolution and 1 day revisit time was collected from the Planet website ([[https://www.planet.com/explorer/](https://www.planet.com/explorer/)]([https://www.planet.com/explorer/](https://www.planet.com/explorer/)) 10 January 2023) for the scene products with a processing level of 3B, with which orthorectified, scaled top of atmosphere radiance (at sensor), or surface reflectance image products are available that are suitable for analytic and visual applications. This product has scene-based framing and is projected to a cartographic projection.