Spatiotemporal radar gesture recognition with hybrid spiking neural networks: balancing accuracy and efficiency

Abstract Radar-based human activity recognition (HAR) offers privacy and robustness over camera-based methods, yet remains computationally demanding for edge deployment. We present the first application of spiking neural networks (SNNs) for radar-based HAR on aircraft marshaling signal classification. Our novel hybrid architecture combines a pre-trained convolutional backbone for spatial feature extraction and leaky integrate-and-fire neurons for temporal processing, inherently capturing gesture dynamics. The model reduces trainable parameters by 88% with under 1% accuracy loss compared to existing state of the art methods, and generalizes well to the Soli gesture dataset. Through systematic comparisons with other three artificial neural network architectures, we demonstrate the trade-offs of spiking computation in terms of accuracy, latency, memory, and energy, establishing SNNs as an efficient and competitive solution for radar-based HAR.