July 12, 2012 Staff Profile: Chopo Ma, Space Geodesist 07/12/2012 Space geodesist Chopo Ma explains the science of Very Long Baseline Interferometry (VLBI): using radio emissions from distant galaxies to create a precise reference frame for the Earth.Watch video Link https://earth.gsfc.nasa.gov/geo/networks/sgp/multimedia/staffprofiles/chopo-ma