Precision Determination of Atmospheric Extinction at Optical and Near IR Wavelengths

Journal Article · Wed Aug 24 04:00:00 EDT 2011 · Astrophys.J.720:811-823,2010

OSTI ID:1023229

Burke, David L; Axelrod, T; Blondin, Stephane; Claver, Chuck; Ivezic, Zeljko; Jones, Lynne; Saha, Abhijit; Smith, Allyn; Smith, R Chris; Stubbs, Christopher W

The science goals for future ground-based all-sky surveys, such as the Dark Energy Survey, PanSTARRS, and the Large Synoptic Survey Telescope, require calibration of broadband photometry that is stable in time and uniform over the sky to precisions of a per cent or better, and absolute calibration of color measurements that are similarly accurate. This performance will need to be achieved with measurements made from multiple images taken over the course of many years, and these surveys will observe in less than ideal conditions. This paper describes a technique to implement a new strategy to directly measure variations of atmospheric transmittance at optical wavelengths and application of these measurements to calibration of ground-based observations. This strategy makes use of measurements of the spectra of a small catalog of bright 'probe' stars as they progress across the sky and back-light the atmosphere. The signatures of optical absorption by different atmospheric constituents are recognized in these spectra by their characteristic dependences on wavelength and airmass. State-of-the-art models of atmospheric radiation transport and modern codes are used to accurately compute atmospheric extinction over a wide range of observing conditions. We present results of an observing campaign that demonstrate that correction for extinction due to molecular constituents and aerosols can be done with precisions of a few millimagnitudes with this technique.

• Research Organization: SLAC National Accelerator Laboratory (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1023229
• Report Number(s): SLAC-PUB-14101
• Journal Information: Astrophys.J.720:811-823,2010, Journal Name: Astrophys.J.720:811-823,2010
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION
ACCURACY
AEROSOLS
Astrophysics
CALIBRATION
COLOR
PERFORMANCE
PHOTOMETRY
RADIATION TRANSPORT
SKY
SPECTRA
STARS
WAVELENGTHS