Investigators Eric Rignot, Jeremie Mouginot, and Bernd Scheuchl have added a 450 m resolution map to their "MEaSUREs InSAR-Based Antarctica Ice Velocity Map" data set. NSIDC offers these data as part of NASA's Making Earth System Data Records for Use in Research Environments (MEaSUREs) program.
Visit the data set landing page for more information and to obtain the data.