Saha S.K. Aperture synthesis: methods and applications to optical astronomy. - New York; London: Springer, 2011. - xxiii, 466 p.: ill. - (Astronomy and astrophysics library). - Ref.: p.439-457. - Ind.: p.459-466. - ISBN 978-1-4419-5709-2  Место хранения:   017 | Институт автоматики и электрометрии CO РАН | Новосибирск | Библиотека

Оглавление / Contents

1 Introduction to Wave Optics .................................. 1 1.1 Preamble ................................................ 1 1.2 Complex Representation of Harmonic Waves ................ 3 1.3 Polarized Waves ......................................... 6 1.3.1 Stokes Parameters ................................ 9 1.3.2 Transformation of Stokes Parameters ............. 12 1.4 Diffraction Fundamentals ............................... 14 1.4.1 Derivation of the Diffracted Field .............. 14 1.4.2 Near and Far-Field Diffractions ................. 16 1.4.3 Diffraction by a Circular Aperture .............. 19 1.5 Image Formation ........................................ 21 1.5.1 Optical Transfer Function ....................... 23 1.5.2 Influence of Aberrations ........................ 26 1.5.3 Resolving Power of a Telescope .................. 27 2 Principles of Interference .................................. 31 2.1 Coherence of Optical Waves ............................. 31 2.1.1 Interference of Partially Coherent Beams ........ 32 2.1.2 Source and Visibility ........................... 36 2.1.3 Power-spectral Density of the Light Beam ........ 40 2.1.4 Mutual Intensity ................................ 43 2.1.5 Propagation of Mutual Coherence ................. 44 2.2 Van Cittert-Zernike Theorem ............................ 46 3 Applications of Interferometry .............................. 51 3.1 Early Stellar Interferometry ........................... 51 3.1.1 Fizeau-Stйphan Interferometer ................... 52 3.1.2 Michelson Stellar Interferometer ................ 54 3.2 Radio Interferometry ................................... 57 3.2.1 The Radio Telescope ............................. 58 3.2.2 The Radio Interferometer ........................ 70 3.2.3 Very Long Baseline Interferometry ............... 81 3.3 Intensity Interferometry ............................... 87 3.3.1 Derivation of the Separation of Two Points on a Star .......................................... 90 3.3.2 Intensity Interferometer at Radio Wavelengths ... 93 3.3.3 Optical Intensity Interferometry ................ 96 3.3.4 Intensity Correlations in Partially Coherent Fields ......................................... 103 3.3.5 Correlation Between the Signals of the Photo- detectors ...................................... 107 3.4 Interferometer for Cosmic Probe ....................... 109 4 Single-dish Diffraction-limited Imaging .................... 115 4.1 Turbulence ............................................ 115 4.1.1 Spectral Description of Turbulence ............. 115 4.1.2 Structure Function for Deriving Kolmogorov Turbulence ..................................... 118 4.1.3 Refractive Index Power-spectral Density ........ 119 4.1.4 Turbulence and Boundary Layer .................. 122 4.1.5 Statistics of the Amplitude and Phase Perturbations .................................. 123 4.1.6 Imaging Through Atmospheric Turbulence ......... 130 4.2 Speckle Interferometry ................................ 137 4.2.1 Deciphering Information from Specklegrams ...... 138 4.2.2 Benefit of Short-exposure Images ............... 141 4.3 Adaptive Optics ....................................... 142 4.3.1 Atmospheric Compensation ....................... 143 4.4 Required Components for an AO System .................. 147 4.4.1 Wavefront Correcting Systems ................... 148 4.4.2 Wavefront Sensors .............................. 152 4.4.3 Wavefront Reconstruction ....................... 157 4.4.4 Wavefront Controller ........................... 158 4.4.5 Laser Guide Star ............................... 160 4.4.6 Multi-conjugate Adaptive Optics ................ 162 5 Diluted-aperture Stellar Interferometry .................... 165 5.1 Methodology of Interferometry ......................... 165 5.1.1 Resolving Power of an Interferometer ........... 167 5.1.2 Astrometry ..................................... 170 5.1.3 Nulling Interferometry ......................... 171 5.2 Baseline Geometry ..................................... 176 5.2.1 Celestial Coordinate System .................... 176 5.2.2 Coordinates for Stellar Interferometry ......... 181 5.2.3 (m, v)-plane Tracks ............................ 186 5.3 Imaging Interferometry ................................ 188 5.3.1 Phase-closure Imaging .......................... 190 5.3.2 Aperture-Synthesis Interferometry .............. 192 6 Basic Tools and Technical Challenges ....................... 205 6.1 Requirements for the LBOI ............................. 205 6.1.1 Delay-line ..................................... 206 6.1.2 Spatial Filtering .............................. 208 6.1.3 Beam Recombination in Reality .................. 211 6.1.4 Pnase and Group Delay Tracking ................. 224 6.1.5 Coherence Envelope ............................. 227 6.1.6 Fringe Acquisition and Tracking ................ 229 6.1.7 Effect of Polarization ......................... 235 6.1.8 Dispersion Effect .............................. 237 6.1.9 Calibration .................................... 238 6.1.10 Role of Adaptive Optics Systems ................ 241 6.2 Limitations and Constraints .......................... 243 6.2.1 Instrumental Constraints ....................... 244 6.2.2 Field-of-view .................................. 246 6.2.3 Sensitivity .................................... 247 6.2.4 Bandwidth Limitations .......................... 249 6.2.5 Limitations due to Atmospheric Turbulence ...... 250 6.2.6 Atmospheric Phase Errors ....................... 251 7 Discrete-Element Interferometers ........................... 253 7.1 Direct-Detection Interferometers ...................... 253 7.1.1 Interféromètre à deux Télescope ................ 253 7.1.2 Grand Interféromètre à deux Télescope (GI2T) ... 255 7.1.3 Mark III Interferometer ........................ 257 7.1.4 Sydney University Stellar Interferometer ....... 258 7.2 Spatial Interferometry in the Infrared (IR) Region .... 260 7.2.1 Heterodyne Detection ........................... 260 7.2.2 Plateau de Calern IR Interferometer ............ 263 7.2.3 Infrared Spatial Interferometer ................ 264 7.3 Arrays with Multiple Telescopes ....................... 265 7.3.1 Cambridge Optical Aperture Synthesis Telescope ...................................... 266 7.3.2 Infrared Optical Telescope Array (IOTA) ........ 267 7.3.3 Navy Prototype Optical Interferometer .......... 268 7.3.4 Palomar Test-bed Interferometer ................ 269 7.3.5 Keck Interferometer ............................ 270 7.3.6 Very Large Telescope Interferometer (VLTI) ..... 270 7.3.7 Center for High Angular Resolution Astronomy Array .......................................... 272 7.4 Interferometers Under Development ..................... 275 7.4.1 Large Binocular Telescopes ..................... 275 7.4.2 Mitaka Optical and Infrared Array .............. 276 7.4.3 Magdalena Ridge Observatory Interferometer ..... 277 7.5 Interferometry with Large Arrays ...................... 278 7.5.1 Optical Very Large Array (OVLA) ................ 278 7.5.2 Hypertelescope Imaging ......................... 279 7.5.3 Carlina Array .................................. 282 7.5.4 High Resolution Coronagraphy ................... 285 7.6 Space-borne Interferometry ............................ 288 7.6.1 Space Interferometry Mission ................... 288 7.6.2 Terrestrial Planet Finder ...................... 289 7.6.3 Darwin Mission ................................. 290 7.6.4 Long-term Perspective .......................... 291 7.7 Reviving Intensity Interferometry ................... 293 8 Image Recovery ............................................. 299 8.1 Data Processing ....................................... 299 8.1.1 Recovery of Visibility Functions ............... 300 8.2 Reconstruction of Objects from Speckles ............... 306 8.2.1 Knox-Thomson Method ............................ 306 8.2.2 Triple Correlation Technique ................... 308 8.2.3 Blind Iterative Deconvolution (BID) Technique .. 311 8.3 Aperture Synthesis Mapping ............................ 313 8.3.1 CLEAN .......................................... 315 8.3.2 Bayesian Statistical Inference ................. 316 8.3.3 Maximum Entropy Method (MEM) ................... 317 8.3.4 Self-calibration Method ........................ 320 9 Astronomy with Diluted Aperture Interferometry ............. 325 9.1 Astronomical Measurements ............................. 325 9.1.1 Limiting Magnitude ............................. 326 9.1.2 Stellar Luminosity ............................. 329 9.1.3 Hertzsprung-Russell (HR) Diagram ............... 330 9.1.4 Derivation of Effective Temperatures ........... 332 9.1.5 Stellar Spectra ................................ 334 9.2 Stellar Parameters .................................... 336 9.2.1 Determining Stellar Distance ................... 336 9.2.2 Evolution of Stars ............................. 338 9.2.3 Resolving Young Stellar Objects (YSO) .......... 341 9.2.4 Diameter across Stellar Evolution .............. 349 9.2.5 Stellar Rotation ............................... 355 9.2.6 Be Stars ....................................... 357 9.2.7 Stellar Surface Structure ...................... 364 9.2.8 Stellar Atmospheres ............................ 366 9.2.9 Circumstellar Shells ........................... 369 9.2.10 Binary Systems ................................. 373 9.2.11 Multiple Systems ............................... 380 9.3 Exploding Stars ....................................... 384 9.3.1 Novae .......................................... 384 9.3.2 Supernovae ..................................... 386 9.4 Extragalactic Sources ................................. 389 9.4.1 Active Galactic Nuclei ......................... 391 9.4.2 Star-Formation in Galaxies ..................... 397 9.5 Infrared Astronomy .................................... 400 9.5.1 Astronomy with IR Interferometry ............... 402 9.5.2 Astrobiology ................................... 410 A Transfer Function of an Optical System ..................... 411 A.l Linear System ......................................... 411 A.2 Measures of Coherence ................................. 413 В Fourier Optics ............................................. 415 B.l Fourier Transform ..................................... 415 В.1.1 Convolution and Cross-Correlation .............. 423 В.1.2 Hankel Transform ............................... 425 С Spatial Frequency Response ................................. 429 C.1 Transfer Function ..................................... 429 D Zernike Representation of Atmospheric Turbulence ........... 433 E Celestial Coordinate System ................................ 437 References .................................................... 439 Index ......................................................... 459