Pub Date : 1900-01-01DOI: 10.1364/adop.1996.athc.11
L. Fini, S. Esposito
We address problems of control loop parameters optimization for tip-tilt correction system based on the approach followed for the T.N.G. tracking system.
本文在T.N.G.跟踪系统的基础上，研究了倾斜校正系统的控制回路参数优化问题。
{"title":"Tip-Tilt Control Loop Optimization","authors":"L. Fini, S. Esposito","doi":"10.1364/adop.1996.athc.11","DOIUrl":"https://doi.org/10.1364/adop.1996.athc.11","url":null,"abstract":"We address problems of control loop parameters optimization for tip-tilt correction system based on the approach followed for the T.N.G. tracking system.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124667405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Astronomers have long known that the resolution in ground-based astronomy is almost always limited by aberrations introduced by the atmosphere. Over the years, researchers have developed a variety of clever pre- and post-detection approaches for correcting these effects. A strong argument can be made for pre-detection correction. It can be shown that the Modulation Transfer Function (MTF) will achieve a maximum at each spatial frequency when the system is unaberrated [1]. Aberrations can only modulate object spatial-frequency information to reduced levels. This modulation could be perfectly inverted in the absence of noise. However, detection of the imagery always introduces noise and inversion schemes result in noise amplification. Therefore, when it can be successfully accomplished, pre-detection correction is preferable to post-detection correction with regard to signal-to-noise ratio.
天文学家早就知道，地面天文学的分辨率几乎总是受到大气引入的像差的限制。多年来，研究人员开发了各种巧妙的检测前和检测后方法来纠正这些影响。可以提出一个强有力的理由来支持检测前校正。可以看出，当系统无像差时，调制传递函数(Modulation Transfer Function, MTF)在每个空间频率处都达到最大值[1]。像差只能将物体的空间频率信息调制到较低的水平。这种调制可以在没有噪声的情况下完全反转。然而，图像的检测总是会引入噪声，而反演方案会导致噪声放大。因此，当能够成功完成时，就信噪比而言，检测前校正优于检测后校正。
{"title":"Roles for Phase Diversity in Compensated Imaging","authors":"R. Paxman","doi":"10.1364/adop.1996.awa.3","DOIUrl":"https://doi.org/10.1364/adop.1996.awa.3","url":null,"abstract":"Astronomers have long known that the resolution in ground-based astronomy is almost always limited by aberrations introduced by the atmosphere. Over the years, researchers have developed a variety of clever pre- and post-detection approaches for correcting these effects. A strong argument can be made for pre-detection correction. It can be shown that the Modulation Transfer Function (MTF) will achieve a maximum at each spatial frequency when the system is unaberrated [1]. Aberrations can only modulate object spatial-frequency information to reduced levels. This modulation could be perfectly inverted in the absence of noise. However, detection of the imagery always introduces noise and inversion schemes result in noise amplification. Therefore, when it can be successfully accomplished, pre-detection correction is preferable to post-detection correction with regard to signal-to-noise ratio.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133278710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1364/adop.1996.athc.2
V. A. Tartakovski, Vladimir P. ukin
Lomonosov and Descartes had known about the first principles of the Hartmann measurements. There are many references1 to a classical version of this method concerning testing the telescope optics. At the modern stage the Shack–Hartmann sensor is used.
{"title":"Scan–Hartmann Wavefront Sensor","authors":"V. A. Tartakovski, Vladimir P. ukin","doi":"10.1364/adop.1996.athc.2","DOIUrl":"https://doi.org/10.1364/adop.1996.athc.2","url":null,"abstract":"Lomonosov and Descartes had known about the first principles of the Hartmann measurements. There are many references1 to a classical version of this method concerning testing the telescope optics. At the modern stage the Shack–Hartmann sensor is used.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133903678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Bruns, T. Barrett, G. Brusa, R. Biasi, D. Gallieni
The MMT will be converted to a single 6.5 m primary mirror in 1997. The new telescope will be equipped with adaptive optics for high-resolution infrared astronomy at wavelengths between 1.6 microns and 5 microns. Atmospheric distortions will be corrected using an adaptive secondary mirror which directly feeds a high-resolution infrared detector. The use of an adaptive secondary maximizes emissivity, which provides high throughput to the imaging detector and efficient wavefront sensing by eliminating many optical elements normally needed in Coudé systems.
{"title":"Adaptive Secondary Development","authors":"D. Bruns, T. Barrett, G. Brusa, R. Biasi, D. Gallieni","doi":"10.1364/adop.1996.afa.1","DOIUrl":"https://doi.org/10.1364/adop.1996.afa.1","url":null,"abstract":"The MMT will be converted to a single 6.5 m primary mirror in 1997. The new telescope will be equipped with adaptive optics for high-resolution infrared astronomy at wavelengths between 1.6 microns and 5 microns. Atmospheric distortions will be corrected using an adaptive secondary mirror which directly feeds a high-resolution infrared detector. The use of an adaptive secondary maximizes emissivity, which provides high throughput to the imaging detector and efficient wavefront sensing by eliminating many optical elements normally needed in Coudé systems.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133126946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1364/adop.1996.awd.16
T. Berkefeld, A. Glindemann
Investigating the tilt correlation as a function of separation angle, exposure time and aperture, the maximum angular distance between the object and the tip-tilt guide star is determined. This distance can be increased by multiple guide stars.
{"title":"Measurements of the Isoplanatic Angle of the Wavefront Tilt","authors":"T. Berkefeld, A. Glindemann","doi":"10.1364/adop.1996.awd.16","DOIUrl":"https://doi.org/10.1364/adop.1996.awd.16","url":null,"abstract":"Investigating the tilt correlation as a function of separation angle, exposure time and aperture, the maximum angular distance between the object and the tip-tilt guide star is determined. This distance can be increased by multiple guide stars.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133551730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adaptive optics components have been used for almost twenty years without major modifications of the basic hardware. Problems connected with cost, power consumption and reliability have pushed several groups to start, investigating the possibility of using different technologies. Of the many technologies under investigation two, in our opinion, demonstrate a high possibility of being an alternative to conventional adaptive mirrors. They are liquid crystal spatial light modulators and and micro-machined mirrors. The USAF Phillips Laboratory, is investigating both these technologies, however here we report, on the results of the liquid crystal work, which has a slightly longer history and more maturity.
{"title":"Liquid Crystals for Adaptive Optics","authors":"S. Restaino, R. Carreras, G. Love","doi":"10.1364/adop.1995.tua47","DOIUrl":"https://doi.org/10.1364/adop.1995.tua47","url":null,"abstract":"Adaptive optics components have been used for almost twenty years without major modifications of the basic hardware. Problems connected with cost, power consumption and reliability have pushed several groups to start, investigating the possibility of using different technologies. Of the many technologies under investigation two, in our opinion, demonstrate a high possibility of being an alternative to conventional adaptive mirrors. They are liquid crystal spatial light modulators and and micro-machined mirrors. The USAF Phillips Laboratory, is investigating both these technologies, however here we report, on the results of the liquid crystal work, which has a slightly longer history and more maturity.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114371222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1364/adop.1996.amb.15
J. Graves
The highly successful AO program at the UH is now planning to expand the curvature technology into higher order correction systems with a unique Vis/IR WFS concept.. Computer simulation have been carried out scaling the current 13 element system now being used at the CFHT on Mauna Kea to a 36 element design. The Vis-IR WFS sensor is expected to increase the performance overall, all as it is used to study young stellar objects that are at many times deeply reddened. An example is HL Tau, in the visible it is around magnitude 14 and at the H band it magnitude 9 or 100 times brighter!
{"title":"Future Directions for the University of Hawaii Adaptive Optics Program","authors":"J. Graves","doi":"10.1364/adop.1996.amb.15","DOIUrl":"https://doi.org/10.1364/adop.1996.amb.15","url":null,"abstract":"The highly successful AO program at the UH is now planning to expand the curvature technology into higher order correction systems with a unique Vis/IR WFS concept.. Computer simulation have been carried out scaling the current 13 element system now being used at the CFHT on Mauna Kea to a 36 element design. The Vis-IR WFS sensor is expected to increase the performance overall, all as it is used to study young stellar objects that are at many times deeply reddened. An example is HL Tau, in the visible it is around magnitude 14 and at the H band it magnitude 9 or 100 times brighter!","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116252726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deconvolution from Wave-Front Sensing (DWFS) has been investigated both through laboratory and field experiments as a method to produce high resolution images from ground based telescopes.1,2,3 This technique has sometimes been referred to as Speclde Holography. With this technique a short exposure focal plane image is recorded simultaneously with an estimate of the atmospheric wave-front. The wave-front estimate is used to calculate an optical transfer function (OTF) for the atmosphere. This OTF estimate is then used in a deconvolution algorithm to correct the focal plane image. A synoptic sketch of a DWFS instrument is shown in figure 1.
{"title":"Comparison of Speckle Image Reconstruction Techniques: Experimental Measurements of Estimator Bias and Signal to Noise Ratio","authors":"D. Dayton, S. Sandven, J. Gonglewski","doi":"10.1364/adop.1995.wb1","DOIUrl":"https://doi.org/10.1364/adop.1995.wb1","url":null,"abstract":"Deconvolution from Wave-Front Sensing (DWFS) has been investigated both through laboratory and field experiments as a method to produce high resolution images from ground based telescopes.1,2,3 This technique has sometimes been referred to as Speclde Holography. With this technique a short exposure focal plane image is recorded simultaneously with an estimate of the atmospheric wave-front. The wave-front estimate is used to calculate an optical transfer function (OTF) for the atmosphere. This OTF estimate is then used in a deconvolution algorithm to correct the focal plane image. A synoptic sketch of a DWFS instrument is shown in figure 1.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121675049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Currie, P. Avizonis, D. M. Dowling, D. O’Leary, J. Nagy, R. Fugate
Image processing methods, highlighting specific hardware systems, will be demonstrated. Correcting spatial dependence and instrumental artifacts of the Point-Spread-Function significantly improves image guality.
图像处理方法，突出具体的硬件系统，将演示。校正空间依赖性和点扩散函数的仪器伪影显著提高图像质量。
{"title":"Approaches for Image Processing Supporting Adaptive Optics","authors":"D. Currie, P. Avizonis, D. M. Dowling, D. O’Leary, J. Nagy, R. Fugate","doi":"10.1364/adop.1995.tua50","DOIUrl":"https://doi.org/10.1364/adop.1995.tua50","url":null,"abstract":"Image processing methods, highlighting specific hardware systems, will be demonstrated. Correcting spatial dependence and instrumental artifacts of the Point-Spread-Function significantly improves image guality.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122014411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. N. Yeskov, B. É. Bonshtedt, S. N. Koreshev, G. I. Lebedeva, V. Parfenov, V. Podoba, V. V. Reznichenko, A. G. Seregin, V. Sidorov, V. N. Smirnov, L. G. Fedina, N. T. Firsov, V. K. Khakunov, I. S. Etsin
At present, some large-scale programs are carried out in various countries that are aimed towards development of a new class of ground and space telescopes for both civil and military use. Being now at different stages of implementation, these programs have been initiated by both scientific and military and political causes and, to a large extent, owing to emerging technologies coupled mainly with active and adaptive optics.
{"title":"Adaptive Astronomical Telescope with Two-Stage Wavefront Correction: current status of a project","authors":"D. N. Yeskov, B. É. Bonshtedt, S. N. Koreshev, G. I. Lebedeva, V. Parfenov, V. Podoba, V. V. Reznichenko, A. G. Seregin, V. Sidorov, V. N. Smirnov, L. G. Fedina, N. T. Firsov, V. K. Khakunov, I. S. Etsin","doi":"10.1364/adop.1995.wc4","DOIUrl":"https://doi.org/10.1364/adop.1995.wc4","url":null,"abstract":"At present, some large-scale programs are carried out in various countries that are aimed towards development of a new class of ground and space telescopes for both civil and military use. Being now at different stages of implementation, these programs have been initiated by both scientific and military and political causes and, to a large extent, owing to emerging technologies coupled mainly with active and adaptive optics.","PeriodicalId":256393,"journal":{"name":"Adaptive Optics","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123691724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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