Complex sentence: Gridless Narrow-Angle Astrometry is an astrometry technique developed at the California Institute of Technology Jet Propulsion Laboratory under contract to NASA, aiming to give an accuracy of 1 micro-arcsecond to the early stages of the Space Interferometry Mission.
Split into simpler sentences: Gridless Narrow-Angle Astrometry (GNAA) is an astrometry technique developed at the California Institute of Technology Jet Propulsion Laboratory under contract to NASA. GNAA was developed to give an accuracy of 1 micro-arcsecond to the early stages of the Space Interferometry Mission.