High Quality Content by WIKIPEDIA articles! The High Accuracy Radial velocity Planet Searcher (HARPS) is a high-precision echelle spectrograph installed in 2002 on ESO`s 3.6m telescope at La Silla Observatory in Chile. The first light was achieved in February 2003. It is a second-generation radial-velocity spectrograph, based on experience with the ELODIE and CORALIE instruments.