First statistics of the isopistonic angle for long baseline interferometry

Description

To reach a suitable limiting magnitude with a multi-aperture interferometer, we need tocophase the different telescopes using a reference source. The latter should be located in thesame isopistonic domain as the science source. We developed a direct analytical expressionof deducing the isopistonic angle from atmospheric optical parameters as seeing, isoplanaticangle and outer scale. All of these atmospheric turbulence parameters are measured by theGeneralized Seeing Monitor (GSM). The first statistics of the isopistonic angle obtained fromthe GSM data are presented and comparison between the major sites over the world arediscussed (La Silla, Cerro Pachon, Paranal, San Pedro, Mt Palomar, Mauna Kea, La Palma,Ouka ̈ımeden, Maydanak, Dome C). Implications of these isopistonic angle statistics on largeinterferometers cophasing in terms of sky coverage and limiting magnitude are discussed.

Abstract

International audience

Additional details