# Data Fusion in Agriculture: Resolving Ambiguities and Closing Data Gaps
## 2 Literature Review
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**Acronym** & **Meaning** & **Acronym** & **Meaning** \\ \hline AMSR-E & Advanced Microwave Scanning Radiometer & MLP & Multilayer Perceptron \\  & on the Earth Observing System & MLR & Multiple Linear Regression \\ ANN & Artificial Neural Network & MOA & Model Output Averaging \\ ASTER & Advanced Spaceborne Thermal Emission and & MODIS & Moderate-Resolution Imaging Spectroradiometer \\  & Reflection & MSDF-ET & Multi-Sensor Data Fusion Model for Actual \\ BK & Block Kriging & Evapotranspiration Estimation & Evapotranspiration Estimation \\ BPNN & Backpropagation Neural Network & MSPI & Maximum Sum of Probabilities Intersections \\ CACAO & Consistent Adjustment of the Climatology & NB & Naive Bayes \\  & to Actual Observations & NDSI & Normalized Difference Spectral Index \\ CHRIS & Compact High Resolution Imaging Spectrometer & NDVI & Normalized Difference Vegetation Index \\ CNN & Convolutional Neural Network & NIR & Near-infrared Spectroscopy \\ CP-ANN & Counter-Propagation Artificial Neural Networks & NMDI & Normalized Multiband Drought Index \\ CV & Computer Vision & OLI & Operational Land Imager \\ DEM & Digital Elevation Model & PCA & Principal Component Analysis \\ DNN & Deep Neural Network & PDI & Perpendicular Drought Index \\ DRF & Distributed Random Forest & PLSR & Partial Least Square Regression \\ ECa & Apparent Soil Electrical Conductivity & RF & Random Forest \\ EDXRF & Energy dispersive X-Ray Fluorescence & RFR & Random Forest Regression \\ EKF & Extended Kalman Filter & RGB & Red-Green-Blue \\ ELM & Extreme Learning Machine & RGB-D & Red–Green–Blue-Depth \\ EMI & Electromagnetic Induction & RK & Regression Kriging \\ ESTARM & Enhanced Spatial and Temporal Adaptive & RTK & Real Time Kinematic \\  & Reflective Fusion Model & SADFAET & Spatiotemporal Adaptive Data Fusion \\ ET & Evapotranspiration & Algorithm for Evapotranspiration Mapping \\ FARMA & Fusion Approach for Remotely-Sensed Mapping & SAR & Synthetic Aperture Radar \\  & of Agriculture & SF & Sensor Fusion \\ GBM & Gradient Boosting Machine & SM & Structure from Motion \\ GKSFM & Gaussian Kernel-Based Spatiotemporal Fusion Model & SKN & Supervised Kohonen Networks \\ GLM & Generalized Linear Model & SMLR & Stepwise Multiple Linear Regression \\ GNSS & Global navigation satellite system & SPA & Successive Projections Algorithm \\ HUTS & High-resolution Urban Thermal Sharpener & SPOT & Satellite Pour l’Observation de la Terre \\ INS & Inertial Navigation System & SRTM & Shuttle Radar Topographic Mission \\ IoT & Internet of Things & STARFM & Spatial and Temporal Adaptive Reflective Fusion \\ ISTDA & Improved Spatial and Temporal Data Fusion & Model & \\  & Approach & SVR & Support Vector Regression \\ kNN & k-Nearest Neighbors & TLS & Terrestrial Laser Scanning \\ LAI & Leaf Area Index & TRMM & Tropical Rainfall Measuring Mission \\ LPT & Laplacian Pyramid Transform & TVDI & Temperature Vegetation Dryness Index \\ LR & Linear Regression & UAV & Unmanned Aerial Vehicle \\ LSTM-NN & Long Short-Term Memory Neural Network & XGBoost & Extreme Gradient Boosting \\ \hline \hline \end{tabular}
\end{table} 
Table 1: List of acronyms. \begin{table}
\begin{tabular}{l l l} \hline \hline
**No.** & **Classes of Data Fusion Technique** & **No.** & **Classes of Data Being Fused** \\ \hline
1 & Regression methods & 1 & RGB images \\
2 & STARFM-like statistical methods & 2 & Multispectral images \\
3 & Geostatistical tools & 3 & Hyperspectral images \\
4 & PCA and derivatives & 4 & Thermal images \\
5 & Kalman filter & 5 & Laser scanning \\
6 & Machine learning & 6 & SAR images \\
7 & Deep learning & 7 & Spectroscopy \\
8 & Decision rules & 8 & Fluorescence images \\
9 & Majority rules & 9 & Soil measurements \\
10 & Model output averaging & 10 & Environmental/ Weather measurements \\
11 & Others & 11 & Inertial measurements \\  & 12 & Position measurements \\  & 13 & Topographic records and elevation models \\  & 14 & Historical data \\  & 15 & Others \\ \hline \hline \end{tabular}
\end{table}