Astrometry is the measurement of positions of stars and other celestial bodies. In our case, we want to measure the position of asteroids, which can be used to refine their orbits. This is important for understanding how these orbits evolve over time and to provide accurate impact hazard assessment in the unlikely event that an asteroid is discovered to be a potential impactor.
Above is an example of data from the Goodman instrument at the SOAR 4.1m telescope. Green dots and lines are stars used by astrometry.net for field identification. Red circles indicate “stellar sources” detected with a simple edge-detection algorithm. Yellow circles indicate stellar sources identified in our astrometric catalog with quality measures that allowed inclusion in the final astrometric fit. The blue circle is the NEO 2013 NX.