atmospheric extinction造句

• It is used to make atmospheric extinction measurements and to monitor light pollution.
• Very low down, however, atmospheric extinction reduces the apparent brightness of the airglow.
• Atmospheric extinction varies with location and altitude.
• It is calculated by multiplying the standard atmospheric extinction curve by the mean airmass calculated over the duration of the observation.
• The strong atmospheric extinction in some wavelength regions ( such as X-ray, ultraviolet, and infrared ) requires the use of space-based observatories.
• The amount of atmospheric extinction depends on the altitude of an object, being lowest at the zenith and at a maximum near the horizon.
• The group were able to demonstrate that the signal may be simulated by a slightly distorted diurnal sine-wave such as may be obtained by differential atmospheric extinction.
• Atmospheric extinction has three main components : Rayleigh scattering by air molecules, scattering by molecular oxygen and ozone, which absorb strongly in the near-ultraviolet, and water, which absorbs strongly in the infrared.
• However, its low altitude over the horizon made these estimates difficult and subject to significant uncertainties, both because of the lack of suitable reference stars in the area and the need for differential atmospheric extinction corrections.
• From the approximately 4, 240 left for us to see, nearly 2, 000 are lost in " atmospheric extinction, " a term used to describe the loss of stars in the thicker atmosphere hugging the horizon in all directions.
• The presence of a "'160 minute cycle "'in the Sun is not substantiated by contemporary solar observations, and the historical signal is considered by mainstream scientists to occur as the redistribution of power from the diurnal cycle as a result of the observation window and atmospheric extinction.
• Objects are located in the night sky using right ascension and declination relative to the celestial equator ( analogous to longitude and latitude on Earth ), and when sidereal time is equal to an object's right ascension the object will be at its highest point in the sky, or " culmination ", at which time it is usually best placed for observation, as atmospheric extinction is minimised.