Our member Dr. Noelia Martínez-Rey (ANU) has been awarded with a prestigious ARC DECRA Fellowship.
Dr. Noelia Martínez Rey (ANU). Credit ‘Diario El Progreso, Lugo’.
Looking at the universe through the Earth’s atmosphere is, for an astronomer, like viewing an art masterpiece from the bottom of a swimming pool. Laser Guide Star Adaptive Optics enable the correction of atmospheric turbulence in the light— the same turbulence that makes stars twinkle, which some may find romantic, but is very unwelcome to astronomers.
Despite advances in telescope size and laser power for satellites, atmospheric correction remains a limiting factor. Laser Guide Star Adaptive Optics (LGS AO) addresses this issue but still requires a bright star for full correction. This DECRA aims to expand atmospheric correction across the entire sky, overcoming the limitations posed by the need for natural stars. It seeks to demonstrate innovative approaches that are applicable not only to astronomy but also to satellite optical communications, addressing the growing demand for data transmission.
The tip-tilt indetermination problem in Laser Guide Stars. Due to the uplink tip-tilt, apparent and true LGS positions are not the same, introducing errors in the measurement.
Atmospheric turbulence is a major hurdle for both astronomy and optical communications. It prevents clear, detailed views of celestial objects and restricts the efficiency and security of satellite communications. The primary goal of this DECRA is to extend atmospheric correction capabilities to the entire sky by solving the so-called “tip-tilt indetermination” problem in Laser Guide Stars: LGS cannot measure the entire atmospheric turbulence, the tip-tilt mode of the atmosphere remains invisible.
The ability of ground-based telescopes equipped with LGS AO systems to produce high-resolution, long-exposure images depends on the availability of suitable tilt reference stars. For example, in the infrared, even if a faint star with a brightness magnitude of 20 could be used to measure the tip-tilt, fewer than 10% of objects at the galactic pole and less than 80% of objects in the galactic plane could be observed near the diffraction limit. No matter how large we build telescopes or how powerful our lasers become, without effective atmospheric correction, performance remains constrained.
This DECRA’s primary goal is to study three different approaches for solving the common challenge of tip-tilt retrieval in ongoing and future Adaptive Optics systems specifically designed for 8-30 m class telescopes and translate the benefits to the emerging field of satellite optical communications.