Fourier components phase accumulation in observation of an object with an orbital telescope
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| 1Kornienko, YV, 1Lyashenko, I, 1Pugach, VV, 1Skuratovskiy, SI 1O. Ya. Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine, Kharkiv, Ukraine |
| Kinemat. fiz. nebesnyh tel (Online) 2020, 36(1):68-84 |
| https://doi.org/10.15407/kfnt2020.01.068 |
| Start Page: Instruments and Devices |
| Language: Ukrainian |
Abstract: In the case of astronomical observations from the surface of the Earth it is difficult to obtain high resolution images due to the distorting influence of the atmosphere. There are two groups of methods for overcoming this influence. First ones are not interfering into the process of image forming, they are related to the processing of already registered images. The methods from the second group represent the construction of specific observational instruments. Putting the instrument out of the atmosphere also may be considered as a method from this group. In this case there is no atmosphere influence, and it is assumed that obtaining the images with diffraction-limited resolution is possible without additional efforts. The factors that may lead to phase distortions while observing with an orbital multi-mirror telescope are discussed. As a method for removing them the total phase accumulation method is proposed. It is designed for compensating the distortion of Fourier component phases, caused by the Earth’s atmosphere. Assumptions as to the statistics of phase distortions, used for its development, are quite general ones and not interfering for its application to space observations. Computer modeling is used to demonstrate the technique effectiveness and studying its possibilities in processing of images from a multi-mirror space telescope. Using of modeling as an instrument for research is motivated by the high cost and complexity of the real experiment, and the requirement of the correct image of an object for evaluating the method error. The aperture configuration of James Webb telescope under construction is used for modeling. The modeling was used to explain the different behavior of phase distortions between space observations and the observations from Earth’s surface. It is demonstrated that in case of space observations the total phase accumulation is required instead of the main phase values accumulation either. It is found that the dependence of the reconstruction error on the number of accumulated images has not monotonous behavior. |
| Keywords: complete phases accumulation, image processing, multi-mirror telescope, phase distortions, spaceborn observations |
References:
1. N. F. Anisimov, R. N. Berdina, N. N. Nechayeva, et al. The probability of obtaining good images of stars when photographing with short exposures, in Atmospheric Optics: Proceedings of Meetings on Atmospheric Optics of the Commission on Optical Atmospheric Instability of the Astrosoviet of the USSR Academy of Sciences (Nauka, Moscow, 1968), pp. 37–44 [in Russian].
2. A. Danzhon and A. Kude. Atmospheric excitement, Astron. Zh. 17 (1), 77–89 (1940).
3. F. Yu. Kanev and V. P. Lukin, Adaptive Optics. Numerical and Experimental Studies (Inst. Opt. Atmos. Sib. Otd. Ross. Akad. Nauk, Tomsk, 2005) [in Russian].
4. E. A. Kaner. On the theory of wave propagation in a medium with random inhomogeneities, Izv. Vyssh. Uchebn. Zaved. Radiofiz. 2, 827–829 (1959).
5. Yu. V. Korniyenko. Image processing in the IRE NAS of Ukraine, in Radiophysics and Electronics: Collection of Scientific Papers (Inst. Radiofiz. Elektron. Im. A. Ya. Usikova Nats. Akad. Nauk Ukr., Kharkiv, 2008), Vol. 13, Special Issue, pp. 423–445.
6. Yu. V. Korniyenko and S. I. Skuratovskiy. On reconstruction of an undistorted image of an object from a series of its images distorted by a medium with random inhomogeneities of the refractive index, Dop. Nats. Akad. Nauk Ukr., No. 2, 83–89 (2010).
7. Yu. V. Korniyenko and S. I. Skuratovskiy. Fourier-component phase accumulation in observation of an object through a turbulent atmosphere: I, Kinematics Phys. Celestial Bodies 27, 304–310 (2011).
https://doi.org/10.3103/S0884591311060043
8. Yu. V. Korniyenko and S. I. Skuratovskiy. Mechanism of information degradation in observations through a randomly inhomogeneous medium, Radiofiz. Radioastron. 17 (1), 39–48 (2012).
9. Yu. V. Korniyenko and S. I. Skuratovskiy. Fourier-component phase accumulation in observation of an object through a turbulent atmosphere: II, Kinematics Phys. Celestial Bodies 28, 77–84 (2012).
https://doi.org/10.3103/S0884591312020043
10. Yu. V. Korniyenko and V. N. Uvarov. Signal accumulation when observing an astronomical object through a turbulent atmosphere, Dokl. Nats. Akad. Nauk Ukr. SSR, Ser. A., No. 4, 60–63 (1987).
11. G. I. Petrov. Development of space research, Vestn. Akad. Nauk Ukr. SSR, No. 5, 65–71 (1969).
12. L. G. Sodin. On the possibility of achieving the diffraction limit of resolution when the telescope operates in a turbulent atmosphere, Pis’ma Astron. Zh. 2, 554–558 (1976).
13. G. A. Tikhov, Major Works: In 5 Volumes (Akad. Nauk Kaz. SSR, Alma-Ata, 1954–1960) [in Russian].
14. K. E. Tsiolkovskiy, Rocket in Outer Space, 2nd ed. (Kaluga, 1924) [in Russian].
15. P. V. Shcheglov, Problems of Optical Astronomy (Nauka, Moskow, 1980) [in Russian].
16. J. A. Bennett. On the power of penetrating into space: The telescopes of William Herschel, J. Hist. Astron. 7/2 (19), 75–108 (1976).
https://doi.org/10.1177/002182867600700201
17. A. Labeyrie. Attainment of diffraction limited resolution in large telescopes by Fourier analysing speckle patterns in star images, Astron. Astrophys. 6, 85–87 (1970).
18. H. Oberth, The Rocket into Planetary Space (De Gruyter, Berlin, 2014).
https://doi.org/10.1515/9783110367560
19. F. Roddier. Redundant versus nonredundant beam recombination in an aperture synthesis with coherent optical arrays, J. Opt. Soc. Am. Ser. A 4, 1396–1401 (1987).
https://doi.org/10.1364/JOSAA.4.001396
20. Scientific Discovery with the James Webb Space Telescope. History Compiled (2018). https://www.jwst.nasa.gov.
21. L. Spitzer, Jr. Astronomical advantages of an extra-terrestrial observatory, Astron. Q. 7, 131–142 (1990).
https://doi.org/10.1016/0364-9229(90)90018-V
22. R. Zimmerman, The Universe in a Mirror: The Saga of the Hubble Space Telescope and the Visionaries Who Built It (Princeton Univ. Press, Princeton, NJ, 2010).
https://doi.org/10.1515/9781400834761