Sky quality

Sky quality parameters

  • Sky extinction effect close to the horizon with TNG and GTC telescopes at the forefront.
    Atmospheric Extinction and Aerosol Optical Depth
    Atmospheric extinction evaluates the transparency of the sky. It can be defined as the amount of light from an astronomical object that is scattered or absorbed by the Earth's atmosphere and not
  • SCIDAR scintillation patterns showing turbulence layers moved by the wind across the telescope pupil (credit: IAC).
    Coherence Time
    The coherence time (τ 0) is the time lapse that the light crossing the Earth atmosphere maintains a near-constant phase relationship, both temporally and spatially.
  • Artist impression of an adaptive optics system using a natural guide star separated an angular distance ~θ0  (credit: Gabriel Pérez -Servcio Multimedia, IAC-)
    Isoplanatic Angle
    The isoplanatic angle (θ 0) is the angle for which the variance of the differences of the phase aberrations suffered by two rays of light passing closely through the atmosphere from different points
  • Top mast of an automatic weather station.
    Meteorology and climate
    Wind speed and direction, wind gust, relative humidity, air temperature, rainfall, insolation, etc.
  • Night Sky Background
    Night Sky Background
    The sky brightness (SB) is the routine measurement of the night sky brightness in a moonless night. It is a sky quality parameter that allows for identifying possible contaminating sources like
  • Evolution of the turbulence profile for the night of 26th May 2006 at the ORM.
    Optical Turbulence
    Turbulence is a particular motion of fluids where the kinetic energy breaks the laminar flow. Optical turbulence refers to the effects that this motion has on light. The optical turbulence in the