IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Large-Scale Quantum Kernels for Hyperspectral Data Classification
Amer Delilbasic, Artur Miroszewski, Agata M. Wijata, Jakub Nalepa, Jakub Mielczarek A B, Morris Riedel, Gabriele Cavallaro
Abstract
Quantum kernel methods have emerged as a promising approach for leveraging high-dimensional feature spaces in machine learning, particularly in domains where classical kernel methods face scalability limitations. In this work, we present the first large-scale study of fidelity-quantum-kernel support vector machines for hyperspectral data classification without requiring heavy prior feature selection or dimensionality reduction. By simulating quantum kernels using tensor network contraction techniques and graphics processing unit acceleration, we overcome the computational bottlenecks traditionally associated with quantum models, achieving quadratic scaling $O(n^2)$ in the number of qubits. Our approach enables the evaluation of quantum kernels on hyperspectral data with hundreds of spectral bands, aligning quantum feature spaces with real-world remote sensing applications. We provide an in-depth analysis of kernel bandwidth optimization, demonstrating its crucial role in mitigating exponential concentration effects and ensuring the model's ability to generalize. Experimental results on binary classification (Indian Pines and methane detection) and multiclass classification (Indian Pines) demonstrate that quantum kernels achieve competitive performance compared to a broad range of state-of-the-art classical baselines. As illustrative cases, on four 50-band splits selected from Indian Pines, the quantum model achieved a $78.0±6.2\%$ accuracy for a binary classification task compared to $72.0±5.0\%$ for the standard radial basis function kernel. For a four-class classification task, the quantum kernel reached $83.3±3.1\%$ accuracy, outperforming several state-of-the-art baselines. On five 75-band splits selected from the methane detection dataset, the quantum approach yielded $58.5±5.0\%$ accuracy versus $55.1±2.5\%$ for the classical counterpart. This study provides a foundation for future exploration of quantum machine learning in high-dimensional Earth observation tasks.