A new algorithm stream function method（SFM）

engendering vector currents from radial currents mapped by two HF Radar sites detection is provided.SFM is based on some oceanographic assumptions.Compared with the common vector combination method（VCM）

vector currents field is obtained using some numerical techniques such as Taylor expansion and least-squares method to avoid the error caused by linear interpolation.The simulation experiments show that SFM has better radial error acceptance and more robust in processing the complicated current field.In addition

SFM-derived currents cover a larger area.The new method is applied on HFSWR（HF surface wave radar） OSMAR test data.Comparison with the current meter in-situ measurements shows that the RMS difference of SFM-derived results is 2 cm·s

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less than VCM-derived results.