Accurately reconstructing continuous flow fields from sparse or indirect measurements remains an open challenge.
A novel flow field reconstruction framework based on divergence-free kernels (DFKs) is introduced.
DFKs-Wen4 (matrix-valued radial basis functions derived from Wendland's C^4 polynomial) are identified as the optimal form of analytically divergence-free approximation for velocity fields.
Experiments demonstrate that DFKs-Wen4 outperform other divergence-free representations in reconstruction accuracy and computational efficiency.