## 2 Materials and Methods
### Review Process  
A structured literature search on the potential of EO for mapping small-scale agriculture and cropping systems in West Africa has been conducted using the Web of Science (WoS) platform (last accessed 1 May 2024). The platform enables an in-depth literature search on the basis of search strings and additional filter criteria such as language, discipline or publication year. We employed conditional statements to ensure the studies addressed each of the three topics: Remote Sensing, West Africa, and Small-Scale Agriculture. To allow some leeway, several synonymous search terms for each topic were employed (Table 1). This search string was applied to the 'topic' (TS) term, which returns results based on title, abstract, and keywords. First, we looked for studies that incorporate RS using a list of commonly used sensors and EO terms. The second search element was concerned with geographical terms defining the study area of West Africa. Third, the search terms for the small-scale agricultural systems are set. Terms like \"agri\" were selected to comprehensively cover various crops and agricultural practices relevant to West Africa. It should be noted that the keyword \"field\" was excluded as it yielded only a few additional relevant articles that could be captured through other keywords during the search string development, while predominantly introducing articles with a divergent focus. Similarly, the keyword \"small\"scale\" did not return additional studies and was therefore excluded from the search string. The search is limited to English papers, classified as \"articles\" document types that were published between 01.01.2000 and 30.04.2024. This confirms that the publications considered have undergone peer review and are both comprehensive and current, providing a thorough overview of the literature on small-scale agriculture in the region. The year 2000 aligns with the launch of MODIS [59], a major EO mission, which \begin{table}
\begin{tabular}{c c} \hline \hline
**Criteria** & **Conditions** \\ \hline \multirow{7}{*}{Remote Sensing and Earth Observation} & “remetely sensed” OR “remote sensing” OR “earth observation“ OR “satellite” OR “IKONOS” OR “Quickbird” OR “WorldView” OR “Pleiades” OR “Rapideye” OR “GeoE” OR “Planet” OR “skycat” OR “SPOT 4” OR “SPOT 5” OR “SPOT 6” OR “SPOT 7” OR “SPOT-Vegetation” OR “Landsat” OR “Sentinel” OR “AVHRR” OR “MODIS” OR “Envisat” OR “Aster” OR “ALOS” OR “TanDEM-X” OR “TerraSAR-X” \\  & OR “DESIS” OR “PRISMA” OR “EnMAP” OR “Hyperion” OR “GEDI” OR “optical imagery” OR “optical satellite” OR “Synthetic Aperture Radar” OR “Radar” OR “RadarSat” OR “COSMO” OR “SRTM” OR “microwave satellite” OR “multispectral satellite” OR “hyperspectral satellite” OR “imaging spectroscopy” OR “thermal satellite” OR “airborne laser scanning” OR “unmanned aerial vehicle“” OR “NDVI” \\ \hline \multirow{7}{*}{West Africa} & “ECOWAS” OR “West” Africa“ OR “Togo” OR “Benin”, OR “Ghana” OR “Ivory Coast” OR “Côte d’Ivoire” OR “Burkina Faso” OR “Cape Verde” OR “Gambia” OR “Guinea” OR “Guinea-Bissau” OR “Liberia” OR “Mali” OR “Mauritania” OR “Niger” OR “Nigeria” OR “Senegal” OR “Sierra Leone” OR “Saint Helena” OR “Ascension” OR “Tristan da Cunha” \\ \hline \multirow{7}{*}{Small-Scale Agriculture and Cropping Systems} & “agri” OR “agriculture” OR “crop“OR “farm” OR “cowpea” OR “groundnut” OR “maize” OR “sorghum” OR “say” OR “yams” OR “shea” OR “cassau” OR “cocoa” OR “rice” OR “corn” OR “cotton” OR “millet” OR “palm” OR “peanut” OR “cashew” \\  & OR “above”ground biomass” OR “vegetation productivity” OR “intercropping” \\ \hline Language & English \\ \hline Document Type & Article \\ \hline Date & 1 January 2000–30 April 2024 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Criteria entered in the WöS search string. The asterisk (*) represents any group of characters, including their absence. began providing critical data, and with the rapid increase in related scientific publications accelerated by opening vast archives, such as Landsat's data repository in 2008 [60].