Assessment of the Effectiveness of Spectral Indices Derived from EnMAP Hyperspectral Imageries Using Machine Learning and Deep Learning Models for Winter Wheat Yield Prediction

Abstract

Highlights: What are the main findings? Multi-temporal EnMAP hyperspectral data combined with machine learning and deep learning models significantly improved the accuracy of winter wheat yield prediction (R2 up to 0.79). SWIR indices were particularly important for early-season estimation, whereas VNIR indices became dominant during later growth stages. What are the implications of the main findings? Integrating hyperspectral observations across phenological stages enables more robust and reliable yield forecasts for precision agriculture. Future missions, such as ESA’s CHIME, will further enhance large-scale, operational crop yield monitoring by providing frequent, high-resolution hyperspectral data. Accurate and timely crop yield estimation is essential for effective agricultural management and global food security, particularly for winter wheat. This study aimed to assess the effectiveness of EnMAP hyperspectral imagery in combination with machine learning and deep learning models for winter wheat yield prediction in Hungary. Using EnMAP images from February and May 2023, along with ground truth yield data from four fields, we derived 10 distinct vegetation indices. Random Forest, Gradient Boosting, and Multilayer Perceptron algorithms were employed, and model performance was evaluated using Mean Absolute Error (MAE) and Coefficient of Determination (R2) values. The results consistently demonstrated that integrating multi-temporal data significantly enhanced predictive accuracy, with the MLP model achieving an R2 of 0.79 and an MAE of 0.27, notably outperforming single-date predictions. Shortwave infrared (SWIR) indices were particularly critical for early-season yield estimations. This research highlights the substantial potential of hyperspectral data and advanced machine learning techniques in precision agriculture, emphasizing the promising role of future missions such as CHIME in further refining and expanding yield estimation capabilities.