Full Content is available to subscribers

Subscribe/Learn More  >
Proceedings Article

Measurement of modulation transfer function of the atmosphere in the surface layer by moire technique

[+] Author Affiliations
Saifollah Rasouli

Institute for Advanced Studies in Basic Sciences (Iran)

Khosro Madanipour, Mohammad T. Tavassoly

Univ. of Tehran (Iran)

Proc. SPIE 6364, Optics in Atmospheric Propagation and Adaptive Systems IX, 63640K (September 28, 2006); doi:10.1117/12.687614
Text Size: A A A
From Conference Volume 6364

  • Optics in Atmospheric Propagation and Adaptive Systems IX
  • Anton Kohnle; Karin Stein
  • Stockholm, Sweden | September 11, 2006

abstract

The turbulence of the atmosphere puts an upper limit on the quality of the image of a ground object obtained by long-exposure photography from low or high altitudes in the atmosphere or in the space. By using good optics and high resolution film or CCD and a stable platform, this limit could be approached but not exceeded. A useful quantity for indicating the magnitude of this limit is the integral of the modulation transfer function (MTF ) associated with the turbulence. In this work, we introduce a new method for measuring the MTF of the atmosphere in the surface layer, based on moire technique. In this technique, from a low frequency Ronchi grating, installed at a certain distance from a digital camera equipped with a tele lens, successive images are recorded and then transferred to a PC. By rotating each image by θ /2 and -θ /2, say ±3°, and superimposing them, a large number moire patterns are produced. The average transmittance function of the superimposed image gratings is measured in a moire fringe interval. The latter function is measured by scanning the moire pattern by a slit parallel to moire fringes. It is shown theoretically that from the Fourier transform of the latter function the MTF of the atmosphere can be deduced, if the MTF s of the imaging system and the grating are given or their effects are negligible. The atmospheric MTF s have been measured at different turbulence conditions. Also, we have studied the behavior of the atmospheric MTF respect to exposure time.

© (2006) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Citation

Saifollah Rasouli ; Khosro Madanipour and Mohammad T. Tavassoly
"Measurement of modulation transfer function of the atmosphere in the surface layer by moire technique", Proc. SPIE 6364, Optics in Atmospheric Propagation and Adaptive Systems IX, 63640K (September 28, 2006); doi:10.1117/12.687614; http://dx.doi.org/10.1117/12.687614


Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).

Figures

Tables

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Proceeding
Sign in or Create a personal account to Buy this proceeding ($15 for members, $18 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.