伊朗宣布取得重大新光学科技成果

政治家不要参与技术问题，技术不是搞搞人事就能搞定的。

擦。真是偷窥利器{:soso_e124:}

伊朗科技界最近在搞大跃进凝聚人性啊

伊朗也是宇宙大国 啊

LZ每次发帖都拖着个大尾巴，版主管理员的都视而不见么？

• 伊朗航天局计划发射至少一颗国产新型卫星，发射窗口：二月一日到二月十一日 [图]
• 热烈祝贺我最亲密老战友伟大朝鲜民主主义人民共和国再次作为世界第一名无光害大国！[图]
• 百科知道『UFO』问题最佳官方答案 [图]
• 爱好者拍摄到「福布斯-土壤」彩色图像 [图]
• 西方智囊集团论述我解放军反卫星武器发展战略模式的理论与实践 [图]
• 谁说敌方「X-37B(OTV-2)」飞行器监视我“天宫一号”? 让咱们也监视监视它吧！[视频]
• 我「萤火一号」十一月九日变轨因敌方放射线武器干扰而失败 [视频] 已关闭
• 第一次公开透露：我军神秘沙漠基地新型分形天线系统终于被正确解密！[图]
• 热烈预祝伊朗与朝鲜实现孙悟空千年飞天梦想圆满成功！

---

只要伊朗伊斯兰共和国革命军卫队挖到两千五百米特深，就肯定能对付敌方的入侵威胁，
将把地下军事设施挖到四千米超深，伊朗伊斯兰共和国一定能取得胜利！
　　——伊朗伊斯兰共和国总统马哈茂德·艾哈迈迪内贾德

---

感觉是伊朗变得这么活跃， 还是TG的新闻媒体变得更加关注伊朗了？

看来已经判明了MD不会动手了。
可以随便叫嚣了

【图】伊朗国产两米口径反射式望远镜

Iran Unveils Largest Home-Made Telescope


（图片来源：http://www.iran-daily.com/1389/5/7/MainPaper/3738/Page/8/MainPaper_3738_8_21851_NewsCut.jpg）


TEHRAN (FNA)- Iran in a ceremony on Tuesday unveiled the country's biggest home-made telescope.

Iran's first Vice-President Mohammad Reza Rahimi unveiled the telescope dubbed as 'Tara' in a ceremony also attended by a number of lawmakers as well as governors of Isfahan and Markazi province in the central city of Golpayegan.

The telescope was manufactured by Golpayegan's Astronomy Society with a fund worth $80,000 to be used in the fields of astronomy, medicine, and military.

In recent years, the Islamic Republic has upped its efforts to achieve supremacy in different fields of science and technology.

Last Friday, President Mahmoud Ahmadinejad said the Islamic Republic plans to launch its first manned shuttle into space by 2019.

来源：
http://english.farsnews.com/newstext.php?nn=8905050764
相关网页：
http://www.iran-daily.com/1389/5/7/MainPaper/3738/Page/8/Index.htm

---

相关帖子
• 伊朗将进行二零一二年第二届伊朗国际微纳卫星比赛
• 【图】伊朗科学家首次成功研制出新型全可见光谱隐形伪装
• 伊朗科学家发明新型纳米碳管能源：能量相当于锂离子电池四倍• 伊朗科学家研制出世界上最小的室温纳米激光装置
• 伊朗航天局『Pars二号』五米分辨率监视卫星首次亮相【视频】
• 热烈预祝伊朗与朝鲜实现孙悟空千年飞天梦想圆满成功！

---

【图】伊朗国产两米口径反射式望远镜

Iran Unveils Largest Home-Made Telescope


（图片来源：http://www.iran-daily.com/1389/5/7/MainPaper/3738/Page/8/MainPaper_3738_8_21851_NewsCut.jpg）


TEHRAN (FNA)- Iran in a ceremony on Tuesday unveiled the country's biggest home-made telescope.

Iran's first Vice-President Mohammad Reza Rahimi unveiled the telescope dubbed as 'Tara' in a ceremony also attended by a number of lawmakers as well as governors of Isfahan and Markazi province in the central city of Golpayegan.

The telescope was manufactured by Golpayegan's Astronomy Society with a fund worth $80,000 to be used in the fields of astronomy, medicine, and military.

In recent years, the Islamic Republic has upped its efforts to achieve supremacy in different fields of science and technology.

Last Friday, President Mahmoud Ahmadinejad said the Islamic Republic plans to launch its first manned shuttle into space by 2019.

来源：
http://english.farsnews.com/newstext.php?nn=8905050764
相关网页：
http://www.iran-daily.com/1389/5/7/MainPaper/3738/Page/8/Index.htm

---

相关帖子
• 伊朗将进行二零一二年第二届伊朗国际微纳卫星比赛
• 【图】伊朗科学家首次成功研制出新型全可见光谱隐形伪装
• 伊朗科学家发明新型纳米碳管能源：能量相当于锂离子电池四倍• 伊朗科学家研制出世界上最小的室温纳米激光装置
• 伊朗航天局『Pars二号』五米分辨率监视卫星首次亮相【视频】
• 热烈预祝伊朗与朝鲜实现孙悟空千年飞天梦想圆满成功！

---

【图】伊朗即将国产三点四米口径反射式望远镜

Site characterization studies for the Iranian National Observatory

Habib G. Khosroshahi

School of Astronomy, Institute for Research in Fundamental Sciences, Tehran, Iran

ABSTRACT

We report on the Iranian National Observatory (INO) ongoing site characterization studies for INO 3.4m optical telescope under development. Iran benefits from high altitude mountains and a relatively dry climate, thus offer many suitable sites for optical observations. The site selection (2001-2007) studies resulted in two promising sites in central Iran, one of which will host the 3.4m telescope. The studies between 2008 and 2010 aimed at detail characterization of the two sites. This involved measurements of a number of parameters including the wind speed and wind direction, astronomical seeing, sky brightness and microthermal variations.

1. INTRODUCTION

The present research and training capabilities in observational astronomy in Iran can, by no mean, respond to the growing demand due to the rapid growth in higher education over the past decade. The existing observational facilities consists of a number of small telescopes in various university campus observatories generally used for undergraduate and graduate training. A medium size optical telescope is thought to be a step to facilitate research in astronomy and observational cosmology. The geographic location of Iran, 32N 53E, relative dry climate and high altitude mountains, offer suitable locations for optical telescopes.

Site selection study for a proposed 2-4 meter class telescope started few years before the INO project received administrative approval. The study led by S. Nasiri (report in reparation) began by collecting and analysis of weather data, seismic hazard data, accessibility and shinny day statistics over central dry regions of the country.

A large number of sites were identified and inspected. When the number of potential sites, mostly scattered around the central desert, was reduced to a manageable number, long term seeing monitoring has also started and continued for two years on 4 different sites with altitudes between 2500m and 3000m.

2. SITE CHARACTERIZATION

It has been shown that the atmospheric turbulence has a strong connection to astronomical seeing. In particular the Fried parameter, r0, which represents the telescope aperture diameter, for which the diffraction-limited image resolution is equal to the FWHM of the seeing-limited image is shown to be determined by refractive index structure constant (Fried 1966) which itself depends on the temperature structure of the atmosphere (e.g. Marks et al 1996).

Site characterization involved measurement of a number of key site parameters such as the wind speed and direction, sky brightness, seeing and microthermal variation profile at the two sites, known as Dinava (3000m) and Gargash (3600m). These two sites are 70km apart. The key objective of the monitoring was to find the best of the two sites for the installation of the 3.4m telescope.

2.1 Wind speed and direction

Typical weather stations were installed in both sites on 12m masts by the end of 2008. They allowed the measurement of temperature, wind speed and direction, barometric pressure and humidity. Wind data recording was performed every 10 minutes at an 8m height above the peak. Two years of measurement indicates that both sites shows a peak wind speed of 4.0-8.0 m/s but despite a 600m higher altitude, the wind speed in Gargash is generally lower than in Dinava.


Figure 1. Left: Gargash site windrose is shown which clearly indicates a dominant wind direction and its intensity. The data covers Jan 2009 - Oct 2010. Dinava site shows a similar windorse. Right: The wind speed histogram is shown for Gargash (top) and Dinava (bottom) during the same period.

2.2 Humidity, clear sky and temperature

Statistically there is about 230 shinny days available for the region. Monitoring the cloud coverage over two years indicates that around 45% clear sky is available annually. This increases to above 70% between June-Oct.

In about 55% of the nights the relative humidity remains below 60%. This increases to over 80% between May-Oct. There is no measurable difference between the two sites in relative humidity.

Temperature variation (Tmax − Tmin) during the night (between twilights) is generally 3 degrees. The temperature changes at a rate of about 0.15 (±0.3) degree celsius per hour between sunset and midnight.

Dinava site is generally about 5 degrees celsius warmer than the Gargash site.

2.3 Seeing measurement

Seeing is one of the most important parameters describing the atmospheric turbulence. Seeing measurement was carried out using DIMM systems (eg. Sarazin & Roddier 1990, Vernin & Munoz 1995, Tokovinin 2002) which comprised of Orion Ritchey-chretien 8 inches telescopes, 44 mm apertures with a 122 mm separation, installed on metal pillar located on a lifted concrete platform providing an altitude of 3.5m above the ground for the telescopes in both sites. The two DIMM systems installed in Gargash and Dinava were cross calibrated at Dinava site using the same configuration. This configuration was kept unchanged for the period of observations June-Oct 2010. A similar method was adopted by the site selection team (2004-2006) using 11-inch telescopes, but on conventional telescope tripod. A comparison of the measured seeing in Dinava and Gargash is shown in Fig 2.

2.4 Microthermal variation measurement and CFD modeling

The main aim of the microthermal measurements is to determine the height of ground layer turbulence which allows an optimization of the cost-height, driven by desire to located the primary mirror above the turbulent layer. In case of complex peak topography, multiple measurements further helps to better constrain the location of the telescope/enclosure.


Figure 2. Seeing distribution compared simultaneously between Gargash (red) and Dinava (blue) sites in summer 2010 obtained from similar DIMM systems. The first quartile seeing in Gargash at 3600m is 0.54 (±0.04) arcsec compared to 0.60 (±0.09) arcsec. Second quartile seeing in Gargash is 0.67 arcsec and 0.72 arcsec for Gargash and Dinava, respectively.

As the time-scale of the temperature variation is of the order of 10-100Hz and the amplitude of the variation is of the order of 0.01 of a degree, the sensitivity of the sensors and the data recording system as well as their response time should be adequately set.

We therefore designed a system to deliver 1 kHz recording frequency with a few × 0.001 degree sensitivity using Platinum wire with high purity and 20 micron diameter.

The microthermal variation measurements were performed in 6 locations (given the complexity of the peak topography) in Gargash site and 2 locations in Dinava site simultaneously in September-October 2010. The sensors were placed at 8 levels with a separation of 1.5m vertically. The horizontal separation of the sensors is 2 meters. A quick analysis of the results show that first mast in the direction of the dominant wind direction (shown in Fig 3) provides a textbook example of the thermal variation profile. There is a clear difference in the recorded variance between the levels which is observed in day and night time. More detailed analysis of the microthermal measurements is in progress.

We have obtained the topographic map of the peak with resolutions of 1 meter and 5 meters for the upper (-30 meter from the peak) and lower (-100 meters of the peak) regions of the peak to be able to perform a Computational Fluid Dynamics (CFD) modeling of the peak under various wind flow and turbulence conditions.

Our initial findings indicate that the boundary layer is about 15-20 meters from the ground.

2.5 Sky brightness

Sky background was measured under photometric conditions in Dinava and Gargash. We find that Gargash site is about 0.4 magnitude darker than the Dinava site owing to a larger distance from major cities. The V-band sky brightness in Dinava and Gargash are 21.6 and 22.0 mag, respectively. A light pollution control project is being planned to preserve the sites for astronomical observations.


Figure 3. An example microthermal variation profile for one of the masts in Gargash. The median of the variance in each level is obtained for 6 consecutive days in Sept 2010. The lower levels show larger variance during the day and night relative to the upper levels.

3. CONCLUDING REMARKS

Our studies indicate a relative advantage of the Gargash site in comparison to Dinava site. Gargash site is found to be darker, benefitting from a better astronomical seeing and also higher altitude and therefore less affected by dust.

ACKNOWLEDGMENTS

The site selection activity was handled by Institute for Advanced Studies Basic Sciences (led by S. Nasiri) between 2001 and 2007. Site characterization and monitoring reported here was handled by the Iranian National Observatory Project team and the Institute for Research in Fundamental Sciences (IPM). I acknowledge the contribution of individuals, R. Mansouri, A. Ardeberg, S. Arbabi, A. Haghighat, A. Behnam, A. Molainejad, A. Roozrokh, A. Danesh, A. Jafarzadeh, R. Ravani, A. Mirhoseini, B, Afzalifar, F. Ghaderi and site monitoring teams.

REFERENCES

Fried D.L., 1966, J. Opt. Soc. Am. 56, 1372
Marks, R.D., Vernin J., Azouit M., Briggs J.W., Burton M.G., Ashley M.C.B and Manigault J.F., 1996, Astron.
Astrophys. Suppl. Ser. 118, 385
Sarazin, M.; Roddier, F., 1990, A&A, 227, 294
Tokovinin, A., 2002, PASP, 114, 1156
Vernin, J., Munoz-Tunon, C., 1995, PASP, 107, 265

来源：
http://arxiv.org/pdf/1101.3883.pdf

---

相关帖子
• 伊朗将进行二零一二年第二届伊朗国际微纳卫星比赛
• 【图】伊朗科学家首次成功研制出新型全可见光谱隐形伪装
• 伊朗科学家发明新型纳米碳管能源：能量相当于锂离子电池四倍• 伊朗科学家研制出世界上最小的室温纳米激光装置
• 伊朗航天局『Pars二号』五米分辨率监视卫星首次亮相【视频】
• 热烈预祝伊朗与朝鲜实现孙悟空千年飞天梦想圆满成功！

---

【图】伊朗即将国产三点四米口径反射式望远镜

Site characterization studies for the Iranian National Observatory

Habib G. Khosroshahi

School of Astronomy, Institute for Research in Fundamental Sciences, Tehran, Iran

ABSTRACT

We report on the Iranian National Observatory (INO) ongoing site characterization studies for INO 3.4m optical telescope under development. Iran benefits from high altitude mountains and a relatively dry climate, thus offer many suitable sites for optical observations. The site selection (2001-2007) studies resulted in two promising sites in central Iran, one of which will host the 3.4m telescope. The studies between 2008 and 2010 aimed at detail characterization of the two sites. This involved measurements of a number of parameters including the wind speed and wind direction, astronomical seeing, sky brightness and microthermal variations.

1. INTRODUCTION

The present research and training capabilities in observational astronomy in Iran can, by no mean, respond to the growing demand due to the rapid growth in higher education over the past decade. The existing observational facilities consists of a number of small telescopes in various university campus observatories generally used for undergraduate and graduate training. A medium size optical telescope is thought to be a step to facilitate research in astronomy and observational cosmology. The geographic location of Iran, 32N 53E, relative dry climate and high altitude mountains, offer suitable locations for optical telescopes.

Site selection study for a proposed 2-4 meter class telescope started few years before the INO project received administrative approval. The study led by S. Nasiri (report in reparation) began by collecting and analysis of weather data, seismic hazard data, accessibility and shinny day statistics over central dry regions of the country.

A large number of sites were identified and inspected. When the number of potential sites, mostly scattered around the central desert, was reduced to a manageable number, long term seeing monitoring has also started and continued for two years on 4 different sites with altitudes between 2500m and 3000m.

2. SITE CHARACTERIZATION

It has been shown that the atmospheric turbulence has a strong connection to astronomical seeing. In particular the Fried parameter, r0, which represents the telescope aperture diameter, for which the diffraction-limited image resolution is equal to the FWHM of the seeing-limited image is shown to be determined by refractive index structure constant (Fried 1966) which itself depends on the temperature structure of the atmosphere (e.g. Marks et al 1996).

Site characterization involved measurement of a number of key site parameters such as the wind speed and direction, sky brightness, seeing and microthermal variation profile at the two sites, known as Dinava (3000m) and Gargash (3600m). These two sites are 70km apart. The key objective of the monitoring was to find the best of the two sites for the installation of the 3.4m telescope.

2.1 Wind speed and direction

Typical weather stations were installed in both sites on 12m masts by the end of 2008. They allowed the measurement of temperature, wind speed and direction, barometric pressure and humidity. Wind data recording was performed every 10 minutes at an 8m height above the peak. Two years of measurement indicates that both sites shows a peak wind speed of 4.0-8.0 m/s but despite a 600m higher altitude, the wind speed in Gargash is generally lower than in Dinava.

fig 1 iran national obsvervatory.JPG (40.32 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 05:56 上传

Figure 1. Left: Gargash site windrose is shown which clearly indicates a dominant wind direction and its intensity. The data covers Jan 2009 - Oct 2010. Dinava site shows a similar windorse. Right: The wind speed histogram is shown for Gargash (top) and Dinava (bottom) during the same period.

2.2 Humidity, clear sky and temperature

Statistically there is about 230 shinny days available for the region. Monitoring the cloud coverage over two years indicates that around 45% clear sky is available annually. This increases to above 70% between June-Oct.

In about 55% of the nights the relative humidity remains below 60%. This increases to over 80% between May-Oct. There is no measurable difference between the two sites in relative humidity.

Temperature variation (Tmax − Tmin) during the night (between twilights) is generally 3 degrees. The temperature changes at a rate of about 0.15 (±0.3) degree celsius per hour between sunset and midnight.

Dinava site is generally about 5 degrees celsius warmer than the Gargash site.

2.3 Seeing measurement

Seeing is one of the most important parameters describing the atmospheric turbulence. Seeing measurement was carried out using DIMM systems (eg. Sarazin & Roddier 1990, Vernin & Munoz 1995, Tokovinin 2002) which comprised of Orion Ritchey-chretien 8 inches telescopes, 44 mm apertures with a 122 mm separation, installed on metal pillar located on a lifted concrete platform providing an altitude of 3.5m above the ground for the telescopes in both sites. The two DIMM systems installed in Gargash and Dinava were cross calibrated at Dinava site using the same configuration. This configuration was kept unchanged for the period of observations June-Oct 2010. A similar method was adopted by the site selection team (2004-2006) using 11-inch telescopes, but on conventional telescope tripod. A comparison of the measured seeing in Dinava and Gargash is shown in Fig 2.

2.4 Microthermal variation measurement and CFD modeling

The main aim of the microthermal measurements is to determine the height of ground layer turbulence which allows an optimization of the cost-height, driven by desire to located the primary mirror above the turbulent layer. In case of complex peak topography, multiple measurements further helps to better constrain the location of the telescope/enclosure.

fig 2 iran national obsvervatory.JPG (32.24 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 05:59 上传

Figure 2. Seeing distribution compared simultaneously between Gargash (red) and Dinava (blue) sites in summer 2010 obtained from similar DIMM systems. The first quartile seeing in Gargash at 3600m is 0.54 (±0.04) arcsec compared to 0.60 (±0.09) arcsec. Second quartile seeing in Gargash is 0.67 arcsec and 0.72 arcsec for Gargash and Dinava, respectively.

As the time-scale of the temperature variation is of the order of 10-100Hz and the amplitude of the variation is of the order of 0.01 of a degree, the sensitivity of the sensors and the data recording system as well as their response time should be adequately set.

We therefore designed a system to deliver 1 kHz recording frequency with a few × 0.001 degree sensitivity using Platinum wire with high purity and 20 micron diameter.

The microthermal variation measurements were performed in 6 locations (given the complexity of the peak topography) in Gargash site and 2 locations in Dinava site simultaneously in September-October 2010. The sensors were placed at 8 levels with a separation of 1.5m vertically. The horizontal separation of the sensors is 2 meters. A quick analysis of the results show that first mast in the direction of the dominant wind direction (shown in Fig 3) provides a textbook example of the thermal variation profile. There is a clear difference in the recorded variance between the levels which is observed in day and night time. More detailed analysis of the microthermal measurements is in progress.

We have obtained the topographic map of the peak with resolutions of 1 meter and 5 meters for the upper (-30 meter from the peak) and lower (-100 meters of the peak) regions of the peak to be able to perform a Computational Fluid Dynamics (CFD) modeling of the peak under various wind flow and turbulence conditions.

Our initial findings indicate that the boundary layer is about 15-20 meters from the ground.

2.5 Sky brightness

Sky background was measured under photometric conditions in Dinava and Gargash. We find that Gargash site is about 0.4 magnitude darker than the Dinava site owing to a larger distance from major cities. The V-band sky brightness in Dinava and Gargash are 21.6 and 22.0 mag, respectively. A light pollution control project is being planned to preserve the sites for astronomical observations.

fig 3 iran national obsvervatory.JPG (35.01 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 06:03 上传

Figure 3. An example microthermal variation profile for one of the masts in Gargash. The median of the variance in each level is obtained for 6 consecutive days in Sept 2010. The lower levels show larger variance during the day and night relative to the upper levels.

3. CONCLUDING REMARKS

Our studies indicate a relative advantage of the Gargash site in comparison to Dinava site. Gargash site is found to be darker, benefitting from a better astronomical seeing and also higher altitude and therefore less affected by dust.

ACKNOWLEDGMENTS

The site selection activity was handled by Institute for Advanced Studies Basic Sciences (led by S. Nasiri) between 2001 and 2007. Site characterization and monitoring reported here was handled by the Iranian National Observatory Project team and the Institute for Research in Fundamental Sciences (IPM). I acknowledge the contribution of individuals, R. Mansouri, A. Ardeberg, S. Arbabi, A. Haghighat, A. Behnam, A. Molainejad, A. Roozrokh, A. Danesh, A. Jafarzadeh, R. Ravani, A. Mirhoseini, B, Afzalifar, F. Ghaderi and site monitoring teams.

REFERENCES

Fried D.L., 1966, J. Opt. Soc. Am. 56, 1372
Marks, R.D., Vernin J., Azouit M., Briggs J.W., Burton M.G., Ashley M.C.B and Manigault J.F., 1996, Astron.
Astrophys. Suppl. Ser. 118, 385
Sarazin, M.; Roddier, F., 1990, A&A, 227, 294
Tokovinin, A., 2002, PASP, 114, 1156
Vernin, J., Munoz-Tunon, C., 1995, PASP, 107, 265

来源：
http://arxiv.org/pdf/1101.3883.pdf

---

相关帖子
• 伊朗将进行二零一二年第二届伊朗国际微纳卫星比赛
• 【图】伊朗科学家首次成功研制出新型全可见光谱隐形伪装
• 伊朗科学家发明新型纳米碳管能源：能量相当于锂离子电池四倍• 伊朗科学家研制出世界上最小的室温纳米激光装置
• 伊朗航天局『Pars二号』五米分辨率监视卫星首次亮相【视频】
• 热烈预祝伊朗与朝鲜实现孙悟空千年飞天梦想圆满成功！

---

【图】伊朗科学家开发一千三百五十二米口径超高望远镜（hypertelescope）

IRAN: laboratory test bench for hypertelescope pupil-plane recombination

F. Allouche, F. Vakilib, A. Glindemann, E. Aristidi, L. Abe, E. Fossat, R. Douet
ESO, Karl-Schwarzschild-strasse 2, 85748, Garching bei Muenchen, Germany;
Laboratoire H. Fizeau, Universite de Nice Sophia-Antipolis, CNRS UMR 6525 Parc Valrose, 06108 Nice Cedex 2, France

ABSTRACT

In 2004, our group proposed IRAN, an alternative beam-combination technique to the so-called hyper-telescope imaging method introduced by Labeyrie in the 1990s. We have recently set up a laboratory experiment aiming at validating our image densification approach instead of the pupil densification scheme of Labeyrie.

In our experiment, seven sub-apertures illuminated by laser sources are recombined using the IRAN scheme.

The validation of the IRAN recombination consists basically in retrieving the point-spread intensity distribution (PSID), demonstrating the conservation of the object-image convolution relation. We will introduce IRAN, compare it to the hyper-telescope, and present the experimental results that we obtained.

Keywords: High angular resolution, Optical Interferometry, Imaging, Beam-combination

1. INTRODUCTION

In the permanent race towards always better and always more, astronomers have already thought about the next generation optical interferometers that will presumably be developed at the kilometric scale and beyond.

Today the VLTI, with maximum baseline of 130 meters for the UTs and 200 meters for the AT's, is already pro-viding us with visibility curves. Tomorrow, giant interferometric arrays (huge baseline and few tens of apertures), will enable us the access to sharp and high angular resolution images of celestial objects. Indeed, it has been proven that interferometers can be exploited in direct imaging mode thanks to Labeyrie's densified hypertelescope technique.

In this ambitious context, Vakili et. al proposed a 39-telescope array, Kiloparsec Explorer for Optical Exo-planet Search, KEOPS, to be built at Dome C of Antarctica. KEOPS is a deployable array of three concentric rings with 7, 13, 19 1.5 m telescopes. The primary goal of KEOPS is the direct detection and the spectral characterization of exoplanets (ExPNs), ultimately hunting exo-Earths in habitable zones. This is done following the nulling method called IRAN.

Despite its pioneering position in the exploitation of interferometers in the imaging mode, in Labeyrie's technique the objet-image convolution relation is modified by the intensity being modulated by the Airy envelope in the image plane. So instead of reconfiguring the pupils, Vakili suggested reconfiguring the images through a concept presented in 2004 under the name of IRAN (Interferometric Remapped Array Nulling). In this paper, we will recall the IRAN concept with its main features, most importantly the recovery of the objet-image convolution relation over a field limited to the super-imposed pupil of the primary telescopes, called hereafter the metapupil.

We will present afterwards the laboratory experiment set for the validation of this recombination concept. And we will discuss by the end of the paper the first results obtained.

2. PRINCIPLE OF IRAN

The method of beam combination that we propose is an alternative to the densified hypertelescope technique introduced by Labeyrie in optical interferometry. The concept of the latter, as its name indicates, is to densify the pupil without introducing any geometrical changes to the array. The densification can be achieved either by increasing the relative size of the elementary apertures or by gathering them to fill up the disk of an equivalent single dish. This, for instance, can be done by reimaging the output pupil using a pyramidal beam combiner.

Thus, the diffraction pattern of a hypertelescope, when all sub-apertures are cophased, resembles the one of a monolithic giant dish. In the IRAN beam-recombination concept, illustrated in Fig. 1, it is the elementary images, given by each telescope, that are reconfigured using a modified Michelson Periscopic set up (or a pyramidal beam combiner depending on the scheme). A relay lens is then used to combine the sub-images leading to a diffraction pattern that, on one hand, is the equivalent to the one of a single giant dish and, on the other hand, conserves the object-image convolution relation.


Fig. 1. The 1D IRAN set up scheme illustrated in this figure is fidele to the "conformal" geometry presented by Labeyrie as the condition for obtaining high-angular resolution images using interferometers. An array of Li lenses, all identical in diameter and focal length, form in their common image plan P1 the individual images given by each aperture. We thus obtain an array of Airy patterns where the position ri of every single Airy pattern is set proportional to the position Ri of the corresponding telescope in order to remain "conformal". The Airy patterns are then recombined using a relay lens. In the focal plane of the latter, or the pupil plane, here denoted by P2, we obtain a fringed pupil image.

IRAN figure 2..JPG (23.26 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 07:01 上传

Fig. 2. This figure presents the fringed pupil image for an N-aperture interferometer. The left part of the figure represents a 1D scheme of the IRAN recombination in the very simple case of only 2 apertures. The right part of th figure represents a 2D scheme for N input pupils and their corresponding intensity in the pupil plane for an on-axis source. The N = 39 configuration is the entire scheme of the KEOPS antarctic interferometer, whereas the N = 7 configuration is a subset of KEOPS, the first ring of its diluted pupil. The fringed image tends more and more towards a pseudo-Airy function when N increases.

2.1 The intensity distribution of off-axis sources

In this section we will recall the analytical expressions of the intensity in both image and pupil planes (resp. P1 and P2) for off-axis sources and monochromatic light. The definitions of the parameters are :

IRAN picture1.JPG (139.63 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 07:06 上传

IRAN figure 3..JPG (43.56 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:08 上传

3. THE LABORATORY EXPERIMENT

We describe here a laboratory optical prototype designed to confirm the optical properties of the IRAN scheme, e.g.

• studying the on-axis monochromatic PSID properties
• testing the translation invariance for an off-axis source and the object-image pseudo convolution relation
• in a further step studying the polychromatic case

IRAN figure 4..JPG (24.51 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:10 上传

Fig. 4. Optical scheme of the science part of the experimental test bench.

The optical design is presented in Fig. 4. An incident plane wave is sent through an afocal beam compressor. In the output pupil plane, a mask with 7 holes holding 7 mini lenses simulates the afocal beams coming from the telescopes of a 7-aperture interferometer. The remainder of the optical bench is composed of a recombining lens and a CCD camera at its focus.

For a sake of simplicity, we chose not to use a periscopic setup for densifying the images such as in Fig. 1. The present design is indeed intrinsically cophased and allows quick access to the interferometric PSID. This simplicity would also allow to place the instrument onto an equatorial mount and observe the sky.

3.1 The Experimental Scheme

In this section we will present the optical components of the bench along with their characteristics.

IRAN figure 5..JPG (72.62 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:14 上传

Fig. 5. A photo of the experiment. It shows the "source" part of the bench (laser+pinhole+beam expander) and the "science" telescope (also a C6) which collects the incident light.

IRAN figure 6..JPG (16.54 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:15 上传

Fig. 6. Pupil entrance of the C6 telescope. Its diameter is equal to 150 mm. The telescope features a central obstruction whose diameter is 60 mm. The focal length is 1.5 m.

3.1.2 The "science" part

The science part, displayed is Fig. 7, starts with the second C6 telescope. Its input pupil contains the 7 sub-apertures of the interferometer. Our first idea was to place a 7 holes mask at its entrance, but it appeared to be unnecessary as we will see hereafter. This C6 is the first element of an afocal beam compressor, a collimating lens of diameter 19 mm and focal length 90 mm being the second one. The parallel light beam is compressed by a factor 17 and has a diameter of 9 mm with a central obstruction of 3.6 mm.

The beam is intercepted by an opaque mask containing a ring of seven circular sub-apertures (Fig. 8 ). Each sub-aperture has a diameter d1 = 1.9 mm, the diameter of the ring is 6 mm. The output collimated beam is spatially filtered through these sub-apertures : this is the reason why we did not place any mask in the entrance pupil of the telescope.

IRAN figure 7..JPG (110.86 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:19 上传

Fig. 7. The Science part of the test bench.

4. TESTING THE MINI-LENSES

The perhaps most challenging and time consuming part of the experiment is related to the mini-lenses, from their acquirement to their insertion in the test bench. Each lenslet has a diameter of 2 mm and a focal ration f/100. This is quite uncommon, and they were specially designed and manufactured by Sud-Est Optique de Precision, France. About 50 mini-lenses were realised in the perspective of a more sophisticated experiment.

The mechanical device that holds them together (Fig. 8) is a sandwich of three layers of aluminium disks 2.54 cm diameter. The first and third layer feature 7 1.9 mm diameter holes, uniformly distributed over a 6 mm diameter circle. The second layer is the same as the two described previously except that each hole has a diameter of 2.1 mm (instead of 1.9). The lenses are inserted in this intermediate layer. The ensemble is then placed in a standard lens holder.

IRAN figure 8..JPG (13.86 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:21 上传

Fig. 8. Mechanical support of the mini-lenses.

Our first task, before we could work properly with the interferometric bench, was to qualify the mini-lenses. These lenses are indeed prototypes and likely to suffer from various optical aberrations. We then realised a test bench (Fig. 9) in which the lenses are placed onto a transparent microscope parallel glass plate and illuminated by a collimated 35 mm diameter laser beam. The glass plate can hold up to 5 lenses. In the focal plane (see Fig. 10), we observe the Airy disk of the lens, as well as its geometrical shadow. The center of this shadow gives the position of the optical axis.

IRAN figure 9..JPG (20.09 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:23 上传

Fig. 9. This is the design of the set up for testing the lenses. As seen from the side i.e the microscope plate holding the lenses, and the 45 degrees titled mirrors are parallel to the test bench.

The selection identifies three main features for each lens :

• the shape of the Airy pattern
• the displacement of the center of the Airy pattern with respect to the center of the optical axis of the lens (tilt introduced on the wavefront by the lens)
• The defocus

We selected the 7 best lenses for the IRAN bench.

IRAN figure 10..JPG (38.26 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:25 上传

Fig. 10. Sample of images of the diffraction pattern given by the mini-lenses during the test. The large circle is the image of the beam. The small circle at the center is the relevant image of the lens under test. The small intense spot in the middle is the Airy pattern. Here we have presented 3 cases, both images A and C show clearly a tilt effect of the lens as can be concluded from the de-centered Airy disk. The position of the Airy pattern is almost at the edge of the geometrical image of the lens in image A and is not centered well enough in the geometrical image of the lens in image C. Image B is the good case.

5. THE FIRST RESULTS

The first experimental results will be divided in two parts. The results obtained in the image plane P1. And the PSID images obtained on the CCD in the pupil plane P2. Indeed, the characteristics of the images of the image plane and their quality are related to the quality of the beam, the optics as well as the bench alignment itself. In the image plane P1, and despite all the care we have put in choosing the lenses, even the best one of them still exhibit a slight small tilt effect (see Fig. 11). We are expecting these small optical aberrations, that do not seem to be leading to catastrophic results in the image plane, to completely distort the PSID. Indeed, the PSID, leaving apart the achromatic function pupil developed in equation 3, is basically an interfering image. And the latter, in the optical range is very delicate and is busted as soon as we have small phase shifts or different optical paths between the different combined beams.

IRAN figure 11..JPG (17.07 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 07:28 上传

Fig. 11. Theory versus Experiment : Intensity distribution in P1. The left plot represents numerical simulations obtained for the same optical characteristics of our bench. The right plot on the other hand is the experimental image. Both images are very similar. The Airy pattern in the experimental one are almost co-centric.

IRAN figure 12..JPG (28.86 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 07:29 上传

Fig. 12. Theory versus Experiment : Intensity in the pupil plane. The left plot is a numerical simulation of the PSID we are supposed to obtain with our test bench. The experimental image (right) of the pupil plane was obtained using the test bench as described in Fig. 4. As a matter of fact the image was taken right after doing the lenses' selection test, the test bench was then free of C6 telescopes (see Fig. 9). Thus the PSID seems to be multiplied by an nonhomogeneous diffraction pattern that is the result of an uncontrolled, or well calibrated, propagation of the light (absence of the telescopes) on one hand and definitely a poor precision in the placement of the different optics in the exact planes. The tiny peak at the center of the PSID, representing the image of a point is still missing in the experimental result due to the problems noted above.

6. CONCLUSION & DISCUSSION

Although the experiment is still young, the first results seem promising. The image of the image plane is rather reassuring since it is the key of obtaining good quality interferences images. Despite the poor quality of the pupil plane, we do believe that reinserting the telescopes will produce a much better fringed pupil image. And if this is true (still to be seen) then we are close to achieving one goal the test bench was designed for. However we are far from being done. We still have to validate the object-image convolution relation as an immediate second step. We would also like to image different sources, extended, polychromatic in order to test the robustness of the IRAN beam recombination concept.

REFERENCES

[1] Labeyrie A., 1996, A&A Suppl. 118, 517.
[2] Vakili F., Aristidi E., Abe L. and Lopez B., 2004 A&A, 421, 174
[3] Abe L., 2004, Proc, SPIE. Volume 5491 : New Frontiers in Stellar Interferometry, p.1519-1527.
[4] Michelson A. A., 1920, ApJ 51, 257.
[5] Goodman J.W., 1996, Introduction to Fourier Optics, Mc Graw-Hill Science.
[6] Vakili F. al., 2004, Proc, SPIE. Volume 5491 : New Frontiers in Stellar Interferometry, p.1580-1586.
[7] Gillet, S., Riaud, P., Lardiere O., Dejonghe J., Schmitt J., Arnold L., Boccaletti A., Horville D., Labeyrie, A., 2003, A&A 400, 393


来源：
http://www.eso.org/sci/libraries/SPIE2008/7013-139.pdf
相关网页：
http://www.chimiefs.ulg.ac.be/SRSL/newSRSL/modules/FCKeditor/upload/File/74_1_2_3/Schmider-Vakili%20p73-78.pdf

---

相关帖子
• 伊朗将进行二零一二年第二届伊朗国际微纳卫星比赛
• 【图】伊朗科学家首次成功研制出新型全可见光谱隐形伪装
• 伊朗科学家发明新型纳米碳管能源：能量相当于锂离子电池四倍• 伊朗科学家研制出世界上最小的室温纳米激光装置
• 伊朗航天局『Pars二号』五米分辨率监视卫星首次亮相【视频】
• 热烈预祝伊朗与朝鲜实现孙悟空千年飞天梦想圆满成功！

---

【图】伊朗科学家开发一千三百五十二米口径超高望远镜（hypertelescope）

IRAN: laboratory test bench for hypertelescope pupil-plane recombination

F. Allouche, F. Vakilib, A. Glindemann, E. Aristidi, L. Abe, E. Fossat, R. Douet
ESO, Karl-Schwarzschild-strasse 2, 85748, Garching bei Muenchen, Germany;
Laboratoire H. Fizeau, Universite de Nice Sophia-Antipolis, CNRS UMR 6525 Parc Valrose, 06108 Nice Cedex 2, France

ABSTRACT

In 2004, our group proposed IRAN, an alternative beam-combination technique to the so-called hyper-telescope imaging method introduced by Labeyrie in the 1990s. We have recently set up a laboratory experiment aiming at validating our image densification approach instead of the pupil densification scheme of Labeyrie.

In our experiment, seven sub-apertures illuminated by laser sources are recombined using the IRAN scheme.

The validation of the IRAN recombination consists basically in retrieving the point-spread intensity distribution (PSID), demonstrating the conservation of the object-image convolution relation. We will introduce IRAN, compare it to the hyper-telescope, and present the experimental results that we obtained.

Keywords: High angular resolution, Optical Interferometry, Imaging, Beam-combination

1. INTRODUCTION

In the permanent race towards always better and always more, astronomers have already thought about the next generation optical interferometers that will presumably be developed at the kilometric scale and beyond.

Today the VLTI, with maximum baseline of 130 meters for the UTs and 200 meters for the AT's, is already pro-viding us with visibility curves. Tomorrow, giant interferometric arrays (huge baseline and few tens of apertures), will enable us the access to sharp and high angular resolution images of celestial objects. Indeed, it has been proven that interferometers can be exploited in direct imaging mode thanks to Labeyrie's densified hypertelescope technique.

In this ambitious context, Vakili et. al proposed a 39-telescope array, Kiloparsec Explorer for Optical Exo-planet Search, KEOPS, to be built at Dome C of Antarctica. KEOPS is a deployable array of three concentric rings with 7, 13, 19 1.5 m telescopes. The primary goal of KEOPS is the direct detection and the spectral characterization of exoplanets (ExPNs), ultimately hunting exo-Earths in habitable zones. This is done following the nulling method called IRAN.

Despite its pioneering position in the exploitation of interferometers in the imaging mode, in Labeyrie's technique the objet-image convolution relation is modified by the intensity being modulated by the Airy envelope in the image plane. So instead of reconfiguring the pupils, Vakili suggested reconfiguring the images through a concept presented in 2004 under the name of IRAN (Interferometric Remapped Array Nulling). In this paper, we will recall the IRAN concept with its main features, most importantly the recovery of the objet-image convolution relation over a field limited to the super-imposed pupil of the primary telescopes, called hereafter the metapupil.

We will present afterwards the laboratory experiment set for the validation of this recombination concept. And we will discuss by the end of the paper the first results obtained.

2. PRINCIPLE OF IRAN

The method of beam combination that we propose is an alternative to the densified hypertelescope technique introduced by Labeyrie in optical interferometry. The concept of the latter, as its name indicates, is to densify the pupil without introducing any geometrical changes to the array. The densification can be achieved either by increasing the relative size of the elementary apertures or by gathering them to fill up the disk of an equivalent single dish. This, for instance, can be done by reimaging the output pupil using a pyramidal beam combiner.

Thus, the diffraction pattern of a hypertelescope, when all sub-apertures are cophased, resembles the one of a monolithic giant dish. In the IRAN beam-recombination concept, illustrated in Fig. 1, it is the elementary images, given by each telescope, that are reconfigured using a modified Michelson Periscopic set up (or a pyramidal beam combiner depending on the scheme). A relay lens is then used to combine the sub-images leading to a diffraction pattern that, on one hand, is the equivalent to the one of a single giant dish and, on the other hand, conserves the object-image convolution relation.

IRAN figure 1..JPG (22.08 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 06:59 上传

Fig. 1. The 1D IRAN set up scheme illustrated in this figure is fidele to the "conformal" geometry presented by Labeyrie as the condition for obtaining high-angular resolution images using interferometers. An array of Li lenses, all identical in diameter and focal length, form in their common image plan P1 the individual images given by each aperture. We thus obtain an array of Airy patterns where the position ri of every single Airy pattern is set proportional to the position Ri of the corresponding telescope in order to remain "conformal". The Airy patterns are then recombined using a relay lens. In the focal plane of the latter, or the pupil plane, here denoted by P2, we obtain a fringed pupil image.

IRAN figure 2..JPG (23.26 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 07:01 上传

Fig. 2. This figure presents the fringed pupil image for an N-aperture interferometer. The left part of the figure represents a 1D scheme of the IRAN recombination in the very simple case of only 2 apertures. The right part of th figure represents a 2D scheme for N input pupils and their corresponding intensity in the pupil plane for an on-axis source. The N = 39 configuration is the entire scheme of the KEOPS antarctic interferometer, whereas the N = 7 configuration is a subset of KEOPS, the first ring of its diluted pupil. The fringed image tends more and more towards a pseudo-Airy function when N increases.

2.1 The intensity distribution of off-axis sources

In this section we will recall the analytical expressions of the intensity in both image and pupil planes (resp. P1 and P2) for off-axis sources and monochromatic light. The definitions of the parameters are :

IRAN picture1.JPG (139.63 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 07:06 上传

IRAN figure 3..JPG (43.56 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:08 上传

3. THE LABORATORY EXPERIMENT

We describe here a laboratory optical prototype designed to confirm the optical properties of the IRAN scheme, e.g.

• studying the on-axis monochromatic PSID properties
• testing the translation invariance for an off-axis source and the object-image pseudo convolution relation
• in a further step studying the polychromatic case

IRAN figure 4..JPG (24.51 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:10 上传

Fig. 4. Optical scheme of the science part of the experimental test bench.

The optical design is presented in Fig. 4. An incident plane wave is sent through an afocal beam compressor. In the output pupil plane, a mask with 7 holes holding 7 mini lenses simulates the afocal beams coming from the telescopes of a 7-aperture interferometer. The remainder of the optical bench is composed of a recombining lens and a CCD camera at its focus.

For a sake of simplicity, we chose not to use a periscopic setup for densifying the images such as in Fig. 1. The present design is indeed intrinsically cophased and allows quick access to the interferometric PSID. This simplicity would also allow to place the instrument onto an equatorial mount and observe the sky.

3.1 The Experimental Scheme

In this section we will present the optical components of the bench along with their characteristics.

IRAN figure 5..JPG (72.62 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:14 上传

Fig. 5. A photo of the experiment. It shows the "source" part of the bench (laser+pinhole+beam expander) and the "science" telescope (also a C6) which collects the incident light.

IRAN figure 6..JPG (16.54 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:15 上传

Fig. 6. Pupil entrance of the C6 telescope. Its diameter is equal to 150 mm. The telescope features a central obstruction whose diameter is 60 mm. The focal length is 1.5 m.

3.1.2 The "science" part

The science part, displayed is Fig. 7, starts with the second C6 telescope. Its input pupil contains the 7 sub-apertures of the interferometer. Our first idea was to place a 7 holes mask at its entrance, but it appeared to be unnecessary as we will see hereafter. This C6 is the first element of an afocal beam compressor, a collimating lens of diameter 19 mm and focal length 90 mm being the second one. The parallel light beam is compressed by a factor 17 and has a diameter of 9 mm with a central obstruction of 3.6 mm.

The beam is intercepted by an opaque mask containing a ring of seven circular sub-apertures (Fig. 8 ). Each sub-aperture has a diameter d1 = 1.9 mm, the diameter of the ring is 6 mm. The output collimated beam is spatially filtered through these sub-apertures : this is the reason why we did not place any mask in the entrance pupil of the telescope.

IRAN figure 7..JPG (110.86 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:19 上传

Fig. 7. The Science part of the test bench.

4. TESTING THE MINI-LENSES

The perhaps most challenging and time consuming part of the experiment is related to the mini-lenses, from their acquirement to their insertion in the test bench. Each lenslet has a diameter of 2 mm and a focal ration f/100. This is quite uncommon, and they were specially designed and manufactured by Sud-Est Optique de Precision, France. About 50 mini-lenses were realised in the perspective of a more sophisticated experiment.

The mechanical device that holds them together (Fig. 8) is a sandwich of three layers of aluminium disks 2.54 cm diameter. The first and third layer feature 7 1.9 mm diameter holes, uniformly distributed over a 6 mm diameter circle. The second layer is the same as the two described previously except that each hole has a diameter of 2.1 mm (instead of 1.9). The lenses are inserted in this intermediate layer. The ensemble is then placed in a standard lens holder.

IRAN figure 8..JPG (13.86 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:21 上传

Fig. 8. Mechanical support of the mini-lenses.

Our first task, before we could work properly with the interferometric bench, was to qualify the mini-lenses. These lenses are indeed prototypes and likely to suffer from various optical aberrations. We then realised a test bench (Fig. 9) in which the lenses are placed onto a transparent microscope parallel glass plate and illuminated by a collimated 35 mm diameter laser beam. The glass plate can hold up to 5 lenses. In the focal plane (see Fig. 10), we observe the Airy disk of the lens, as well as its geometrical shadow. The center of this shadow gives the position of the optical axis.

IRAN figure 9..JPG (20.09 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:23 上传

Fig. 9. This is the design of the set up for testing the lenses. As seen from the side i.e the microscope plate holding the lenses, and the 45 degrees titled mirrors are parallel to the test bench.

The selection identifies three main features for each lens :

• the shape of the Airy pattern
• the displacement of the center of the Airy pattern with respect to the center of the optical axis of the lens (tilt introduced on the wavefront by the lens)
• The defocus

We selected the 7 best lenses for the IRAN bench.

IRAN figure 10..JPG (38.26 KB, 下载次数: 1)

下载附件 保存到相册

2012-2-25 07:25 上传

Fig. 10. Sample of images of the diffraction pattern given by the mini-lenses during the test. The large circle is the image of the beam. The small circle at the center is the relevant image of the lens under test. The small intense spot in the middle is the Airy pattern. Here we have presented 3 cases, both images A and C show clearly a tilt effect of the lens as can be concluded from the de-centered Airy disk. The position of the Airy pattern is almost at the edge of the geometrical image of the lens in image A and is not centered well enough in the geometrical image of the lens in image C. Image B is the good case.

5. THE FIRST RESULTS

The first experimental results will be divided in two parts. The results obtained in the image plane P1. And the PSID images obtained on the CCD in the pupil plane P2. Indeed, the characteristics of the images of the image plane and their quality are related to the quality of the beam, the optics as well as the bench alignment itself. In the image plane P1, and despite all the care we have put in choosing the lenses, even the best one of them still exhibit a slight small tilt effect (see Fig. 11). We are expecting these small optical aberrations, that do not seem to be leading to catastrophic results in the image plane, to completely distort the PSID. Indeed, the PSID, leaving apart the achromatic function pupil developed in equation 3, is basically an interfering image. And the latter, in the optical range is very delicate and is busted as soon as we have small phase shifts or different optical paths between the different combined beams.

IRAN figure 11..JPG (17.07 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 07:28 上传

Fig. 11. Theory versus Experiment : Intensity distribution in P1. The left plot represents numerical simulations obtained for the same optical characteristics of our bench. The right plot on the other hand is the experimental image. Both images are very similar. The Airy pattern in the experimental one are almost co-centric.

IRAN figure 12..JPG (28.86 KB, 下载次数: 0)

下载附件 保存到相册

2012-2-25 07:29 上传

Fig. 12. Theory versus Experiment : Intensity in the pupil plane. The left plot is a numerical simulation of the PSID we are supposed to obtain with our test bench. The experimental image (right) of the pupil plane was obtained using the test bench as described in Fig. 4. As a matter of fact the image was taken right after doing the lenses' selection test, the test bench was then free of C6 telescopes (see Fig. 9). Thus the PSID seems to be multiplied by an nonhomogeneous diffraction pattern that is the result of an uncontrolled, or well calibrated, propagation of the light (absence of the telescopes) on one hand and definitely a poor precision in the placement of the different optics in the exact planes. The tiny peak at the center of the PSID, representing the image of a point is still missing in the experimental result due to the problems noted above.

6. CONCLUSION & DISCUSSION

Although the experiment is still young, the first results seem promising. The image of the image plane is rather reassuring since it is the key of obtaining good quality interferences images. Despite the poor quality of the pupil plane, we do believe that reinserting the telescopes will produce a much better fringed pupil image. And if this is true (still to be seen) then we are close to achieving one goal the test bench was designed for. However we are far from being done. We still have to validate the object-image convolution relation as an immediate second step. We would also like to image different sources, extended, polychromatic in order to test the robustness of the IRAN beam recombination concept.

REFERENCES

[1] Labeyrie A., 1996, A&A Suppl. 118, 517.
[2] Vakili F., Aristidi E., Abe L. and Lopez B., 2004 A&A, 421, 174
[3] Abe L., 2004, Proc, SPIE. Volume 5491 : New Frontiers in Stellar Interferometry, p.1519-1527.
[4] Michelson A. A., 1920, ApJ 51, 257.
[5] Goodman J.W., 1996, Introduction to Fourier Optics, Mc Graw-Hill Science.
[6] Vakili F. al., 2004, Proc, SPIE. Volume 5491 : New Frontiers in Stellar Interferometry, p.1580-1586.
[7] Gillet, S., Riaud, P., Lardiere O., Dejonghe J., Schmitt J., Arnold L., Boccaletti A., Horville D., Labeyrie, A., 2003, A&A 400, 393


来源：
http://www.eso.org/sci/libraries/SPIE2008/7013-139.pdf
相关网页：
http://www.chimiefs.ulg.ac.be/SRSL/newSRSL/modules/FCKeditor/upload/File/74_1_2_3/Schmider-Vakili%20p73-78.pdf

---

相关帖子
• 伊朗将进行二零一二年第二届伊朗国际微纳卫星比赛
• 【图】伊朗科学家首次成功研制出新型全可见光谱隐形伪装
• 伊朗科学家发明新型纳米碳管能源：能量相当于锂离子电池四倍• 伊朗科学家研制出世界上最小的室温纳米激光装置
• 伊朗航天局『Pars二号』五米分辨率监视卫星首次亮相【视频】
• 热烈预祝伊朗与朝鲜实现孙悟空千年飞天梦想圆满成功！

---

鄙视LZ，每次发帖都拖个臭尾巴，看着就恶心！

{:soso_e111:}

尼米兹 发表于 2012-2-25 09:51
鄙视LZ，每次发帖都拖个臭尾巴，看着就恶心！

MahmoudClone 2012-2-25 10:13
到底是什么意思？好多会员都加个“相关帖子”（已减少到六个连接，没比其他会员更多）{:soso_e135:}

MahmoudClone  2012-2-25 10:20
尼米兹怎么又变成游击队员呢？

emellzzq   2012-2-25 10:22
如果发现有“加个‘相关帖子’”的情况，你可以点右下方的举报。你自己不要学。大家想看更多的话，自己会通过原文的地址去看。马上把你这些帖子里的“相关帖子”都编辑掉。

MahmoudClone  2012-2-25 10:28
到底有没有这样的一条规定吗？连接请给一下。

emellzzq   2012-2-25 10:32
管理处理由第一条就是广告信息，如果不是你的内容里真有货，我早就通知超版直接灭了这广告ID了。

MahmoudClone 2012-2-25 10:42
不过，本人从来没看到其他会员因为加上六个‘相关帖子’连接被尼米兹骂鄙视LZ，也更没看到任何一个会员因为加上六个‘相关帖子’连接被扣过分两次！
这种行为正明明显的歧视！

{:soso_e111:}

emellzzq   2012-2-25 11:32
如果你认为我处理不当，可以到站务版申斥。

MahmoudClone 2012-2-25 11:27 对 尼米兹 关于你在“伊朗宣布取得重大新光学科技成果”的帖子
加上六个‘相关帖子’连接的会员特别多，本人只是看到之后才模仿这种做法！
本人从来没看到其他会员因为加上六个‘相关帖子’连接被尼米兹骂，简直就是鸡蛋挑骨头！
这种行为正明明显的歧视！

MahmoudClone 2012-2-25 11:43 对 尼米兹
鄙视LZ，每次发帖都拖个臭尾巴，看着就恶心！
平时看着别的会员加‘相关帖子’为什么不恶心呢？为什么不举报呢？

MahmoudClone 2012-2-25 11:53 对 尼米兹
尼米兹怎么今天突然变成游击队员呢？

专门搞个电视台，24小时播放对国际空间站的监视，让全球人民信服才是

PT：惭愧，俺要求太高了，只要求国际空间站过境时候播放监控画面即可

专门搞个电视台，24小时播放对国际空间站的监视，让全球人民信服才是

PT：惭愧，俺要求太高了，只要求国际空间站过境时候播放监控画面即可

看来波斯比3哥还能吹，这样的地摊小报也敢上啦忽悠？

后面那两个施卡明明是星特朗的镜子么........还是20cm的，我也有。

真是文化和民族性格不同，中国人的低调是不会开发布会宣传这个的。