Star sensors are an essential instrument used to determine the attitude of satellites by identifying the stars in the field of view. The high cost and large sizes of commercially available star sensors pose challenges for small satellite missions. We at the Indian Institute of Astrophysics have developed a low-cost star sensor, StarberrySense, based on the Raspberry Pi as the main controller and built from commercial off-the-shelf components. The StarberrySense was flown on the PS4 experimental orbital platform module of the Polar Satellite Launch Vehicle C-55 by the Indian Space Research Organization. This work describes the flight hardware, environmental tests in preparation for the flight, and in-orbit performance of our StarberrySense.
{"title":"Low-cost Raspberry Pi star sensor for small satellites. II: StarberrySense flight and in-orbit performance","authors":"Bharat Chandra P., Binukumar G. Nair, Shubhangi Jain, Shubham Jankiram Ghatul, Mahesh Babu S., Rekhesh Mohan, Margarita Safonova, Jayant Murthy","doi":"10.1117/1.jatis.10.2.026002","DOIUrl":"https://doi.org/10.1117/1.jatis.10.2.026002","url":null,"abstract":"Star sensors are an essential instrument used to determine the attitude of satellites by identifying the stars in the field of view. The high cost and large sizes of commercially available star sensors pose challenges for small satellite missions. We at the Indian Institute of Astrophysics have developed a low-cost star sensor, StarberrySense, based on the Raspberry Pi as the main controller and built from commercial off-the-shelf components. The StarberrySense was flown on the PS4 experimental orbital platform module of the Polar Satellite Launch Vehicle C-55 by the Indian Space Research Organization. This work describes the flight hardware, environmental tests in preparation for the flight, and in-orbit performance of our StarberrySense.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140805618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Integral field spectroscopy (IFS) is an observational method for obtaining spatially resolved spectra over a specific field of view (FoV) in a single exposure. In recent years, near-infrared IFS has gained importance in observing objects with strong dust attenuation or at a high redshift. One limitation of existing near-infrared IFS instruments is their relatively small FoV, less than 100 arcsec2, compared with optical instruments. Therefore, we developed a near-infrared (0.9 to 2.5 μm) image-slicer type integral field unit (IFU) with a larger FoV of 13.5×10.4 arcsec2 by matching a slice width to a typical seeing size of 0.4 arcsec. The IFU has a compact optical design utilizing off-axis ellipsoidal mirrors to reduce aberrations. Complex optical elements were fabricated using an ultra-precision cutting machine to achieve root mean square surface roughness of less than 10 nm and a P-V shape error of less than 300 nm. The ultra-precision machining can also simplify the alignment procedures. The on-sky performance evaluation confirmed that the image quality and the throughput of the IFU were as designed. In conclusion, we successfully developed a compact IFU utilizing an ultra-precision cutting technique, almost fulfilling the requirements.
{"title":"Development of a near-infrared wide-field integral field unit by ultra-precision diamond cutting","authors":"Kosuke Kushibiki, Shinobu Ozaki, Masahiro Takeda, Takuya Hosobata, Yutaka Yamagata, Shinya Morita, Toshihiro Tsuzuki, Keiichi Nakagawa, Takao Saiki, Yutaka Ohtake, Kenji Mitsui, Hirofumi Okita, Yutaro Kitagawa, Yukihiro Kono, Kentaro Motohara, Hidenori Takahashi, Masahiro Konishi, Natsuko Kato, Shuhei Koyama, Nuo Chen","doi":"10.1117/1.jatis.10.1.015004","DOIUrl":"https://doi.org/10.1117/1.jatis.10.1.015004","url":null,"abstract":"Integral field spectroscopy (IFS) is an observational method for obtaining spatially resolved spectra over a specific field of view (FoV) in a single exposure. In recent years, near-infrared IFS has gained importance in observing objects with strong dust attenuation or at a high redshift. One limitation of existing near-infrared IFS instruments is their relatively small FoV, less than 100 arcsec2, compared with optical instruments. Therefore, we developed a near-infrared (0.9 to 2.5 μm) image-slicer type integral field unit (IFU) with a larger FoV of 13.5×10.4 arcsec2 by matching a slice width to a typical seeing size of 0.4 arcsec. The IFU has a compact optical design utilizing off-axis ellipsoidal mirrors to reduce aberrations. Complex optical elements were fabricated using an ultra-precision cutting machine to achieve root mean square surface roughness of less than 10 nm and a P-V shape error of less than 300 nm. The ultra-precision machining can also simplify the alignment procedures. The on-sky performance evaluation confirmed that the image quality and the throughput of the IFU were as designed. In conclusion, we successfully developed a compact IFU utilizing an ultra-precision cutting technique, almost fulfilling the requirements.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140026558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1117/1.jatis.10.1.019801
Susan F. Redmond, Leonid Pogorelyuk, Laurent Pueyo, Emiel Por, James Noss, Scott D. Will, Iva Laginja, Keira Brooks, Matthew Maclay, J. Fowler, N. Jeremy Kasdin, Marshall D. Perrin, Rémi Soummer
Erratum corrects errors on Figs. 4 and 5.
勘误更正了图 4 和图 5 中的错误。
{"title":"Implementation of a dark zone maintenance algorithm for speckle drift correction in a high contrast space coronagraph (Erratum)","authors":"Susan F. Redmond, Leonid Pogorelyuk, Laurent Pueyo, Emiel Por, James Noss, Scott D. Will, Iva Laginja, Keira Brooks, Matthew Maclay, J. Fowler, N. Jeremy Kasdin, Marshall D. Perrin, Rémi Soummer","doi":"10.1117/1.jatis.10.1.019801","DOIUrl":"https://doi.org/10.1117/1.jatis.10.1.019801","url":null,"abstract":"Erratum corrects errors on Figs. 4 and 5.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140026560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Prototype Segmented Mirror Telescope is a 1.3 m aperture, seven segment telescope, being developed as a technology demonstrator for India’s large optical-IR telescope project. For this segmented mirror telescope, a Shack Hartmann sensor based alignment device has been designed and developed. The device not only precisely captures the segment misalignment but also measures the segment focus error with an accuracy of a few microns and hence helps in the tip-tilt correction and co-focusing of the mirror segments. The device is designed to work primarily in two different modes: the Shack–Hartmann mode and the imaging mode. After completion of the alignment procedure, the final image quality can be checked in the imaging mode. The device is designed in such a way that it also has a provision to conduct the Keck kind of phasing experiment with one pair of mirror segments. To make the device cost effective, only off-the-shelf components are used. The optical design and opto-mechanical analysis of the device were carried out using Zemax and SolidWorks software. Then, the device was realized and its extensive testing was carried out in the laboratory. Here, we have presented the details of the opto-mechanical design and analysis as well as the preliminary results of performance tests conducted in the laboratory.
{"title":"Development of an alignment device for the Prototype Segmented Mirror Telescope","authors":"Radhika Dharmadhikari, Padmakar Parihar, Mohammed Muthahar Rafeeq Ahmed, Govinda Koravangala Venkatapathaiah, Madan Mohan Kemkar, Himanshu Kunjam","doi":"10.1117/1.jatis.10.1.019002","DOIUrl":"https://doi.org/10.1117/1.jatis.10.1.019002","url":null,"abstract":"The Prototype Segmented Mirror Telescope is a 1.3 m aperture, seven segment telescope, being developed as a technology demonstrator for India’s large optical-IR telescope project. For this segmented mirror telescope, a Shack Hartmann sensor based alignment device has been designed and developed. The device not only precisely captures the segment misalignment but also measures the segment focus error with an accuracy of a few microns and hence helps in the tip-tilt correction and co-focusing of the mirror segments. The device is designed to work primarily in two different modes: the Shack–Hartmann mode and the imaging mode. After completion of the alignment procedure, the final image quality can be checked in the imaging mode. The device is designed in such a way that it also has a provision to conduct the Keck kind of phasing experiment with one pair of mirror segments. To make the device cost effective, only off-the-shelf components are used. The optical design and opto-mechanical analysis of the device were carried out using Zemax and SolidWorks software. Then, the device was realized and its extensive testing was carried out in the laboratory. Here, we have presented the details of the opto-mechanical design and analysis as well as the preliminary results of performance tests conducted in the laboratory.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140037049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1117/1.jatis.10.1.014006
Jeremy J. Drake, Simon R. Bandler, Marco Barbera, Enrico Bozzo, William R. Dunn, Cecilia Garraffo, Thomas Gauron, Ludovic Genolet, Janice Houston, Richard L. Kelley, Caroline A. Kilbourne, Ralph P. Kraft, Maurice A. Leutenegger, Ugo Lo Cicero, Seán C. McEntee, Daniel J. Patnaude
The Line Emission Mapper X-ray Probe-class mission concept is based on a microcalorimeter array tuned to energies in the range 0.1 to 2 keV. The study of cosmic ecosystems defines the directed portion of the Line Emission Mapper (LEM) mission, thus LEM has been optimized for observations of diffuse X-ray-emitting gas, largely with very low surface brightness. To broaden the range of targets that general observers can study with LEM, we have investigated the particular needs for UV/optical bright stars and solar-system objects. X-ray microcalorimeters are susceptible to degraded energy resolution that can result from thermal noise from residual UV, optical, and IR radiation. Using the present baseline design of the microcalorimeter thermal filters, we compute the UV-IR loading expected from bright stars over the effective temperature range 3500 to 39,000 K and from solar-system objects. The dominant leak of out-of-band energy is in the far-UV around 1500 Å, with a secondary peak of throughput around 4000 Å. For stars with magnitudes V<10 and for all solar-system planets as well as the Moon, the loading is significant, indicating that additional UV/optical blocking is essential if bright objects are to be observed. We have investigated the efficacy of several filter options for optical-blocking filters on the LEM filter wheel, demonstrating that new technology development is not necessary to open up many of these classes of objects to investigation with the high spectral resolution of LEM.
线发射绘图仪 X 射线探测器级飞行任务的概念是基于一个微量热计阵列，其能量范围为 0.1 至 2 千伏。对宇宙生态系统的研究确定了线发射绘图仪（LEM）任务的定向部分，因此 LEM 已针对观测漫射 X 射线发射气体进行了优化，这些气体大多表面亮度很低。为了扩大普通观测者可以利用 LEM 研究的目标范围，我们对紫外线/光学明亮恒星和太阳系天体的特殊需求进行了调查。X 射线微量热仪容易受到能量分辨率下降的影响，而能量分辨率下降可能是由于残余紫外线、光学和红外辐射的热噪声造成的。利用微量热计热滤波器的现有基线设计，我们计算了有效温度范围在 3500 至 39,000 K 之间的明亮恒星和太阳系天体的紫外-红外负载。带外能量的主要泄漏在 1500 Å 左右的远紫外波段，4000 Å 左右是吞吐量的次高峰。对于星等 V<10 的恒星和所有太阳系行星以及月球来说，带外能量泄漏非常严重，这表明如果要观测明亮的天体，额外的紫外线/光学阻挡是必不可少的。我们研究了 LEM 滤光片轮上几种光学阻挡滤光片的功效，证明不需要开发新的技术，就可以利用 LEM 的高光谱分辨率对许多这类天体进行观测。
{"title":"Extending the high-resolution X-ray spectroscopy of Line Emission Mapper to UV/optically-bright sources","authors":"Jeremy J. Drake, Simon R. Bandler, Marco Barbera, Enrico Bozzo, William R. Dunn, Cecilia Garraffo, Thomas Gauron, Ludovic Genolet, Janice Houston, Richard L. Kelley, Caroline A. Kilbourne, Ralph P. Kraft, Maurice A. Leutenegger, Ugo Lo Cicero, Seán C. McEntee, Daniel J. Patnaude","doi":"10.1117/1.jatis.10.1.014006","DOIUrl":"https://doi.org/10.1117/1.jatis.10.1.014006","url":null,"abstract":"The Line Emission Mapper X-ray Probe-class mission concept is based on a microcalorimeter array tuned to energies in the range 0.1 to 2 keV. The study of cosmic ecosystems defines the directed portion of the Line Emission Mapper (LEM) mission, thus LEM has been optimized for observations of diffuse X-ray-emitting gas, largely with very low surface brightness. To broaden the range of targets that general observers can study with LEM, we have investigated the particular needs for UV/optical bright stars and solar-system objects. X-ray microcalorimeters are susceptible to degraded energy resolution that can result from thermal noise from residual UV, optical, and IR radiation. Using the present baseline design of the microcalorimeter thermal filters, we compute the UV-IR loading expected from bright stars over the effective temperature range 3500 to 39,000 K and from solar-system objects. The dominant leak of out-of-band energy is in the far-UV around 1500 Å, with a secondary peak of throughput around 4000 Å. For stars with magnitudes V<10 and for all solar-system planets as well as the Moon, the loading is significant, indicating that additional UV/optical blocking is essential if bright objects are to be observed. We have investigated the efficacy of several filter options for optical-blocking filters on the LEM filter wheel, demonstrating that new technology development is not necessary to open up many of these classes of objects to investigation with the high spectral resolution of LEM.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140148009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1117/1.jatis.10.1.015003
Philippa Molyneux, Todd Veach, Michael Davis, Gregory Fletcher, Jerry Goldstein
We present extreme ultraviolet (EUV) transmission measurements of two thin-film filters designed to obtain improved images of plasmaspheric He+, and the first global images of O+/O++ in the dense oxygen torus. Compared to previous He+ 30.4 nm imaging that used an Al filter, we show that a combined Al+C filter achieves superior rejection of 58.4 nm background from neutral helium (He I). We show that an indium filter provides both the required transmission at 83.4 nm and adequate rejection of brighter He I (58.4 nm) and H I (121.6 nm) background emissions. We find that the In transmission at 58.4 nm is a factor of ∼16 lower than predicted based on optical constants that rely on interpolations at λ<68 nm. We show that the observed lower 58.4 nm transmission is consistent with alternative optical constants derived from previous lab measurements.
{"title":"New extreme ultraviolet transmission measurements of two thin-film filters for imaging of plasmaspheric cold ions","authors":"Philippa Molyneux, Todd Veach, Michael Davis, Gregory Fletcher, Jerry Goldstein","doi":"10.1117/1.jatis.10.1.015003","DOIUrl":"https://doi.org/10.1117/1.jatis.10.1.015003","url":null,"abstract":"We present extreme ultraviolet (EUV) transmission measurements of two thin-film filters designed to obtain improved images of plasmaspheric He+, and the first global images of O+/O++ in the dense oxygen torus. Compared to previous He+ 30.4 nm imaging that used an Al filter, we show that a combined Al+C filter achieves superior rejection of 58.4 nm background from neutral helium (He I). We show that an indium filter provides both the required transmission at 83.4 nm and adequate rejection of brighter He I (58.4 nm) and H I (121.6 nm) background emissions. We find that the In transmission at 58.4 nm is a factor of ∼16 lower than predicted based on optical constants that rely on interpolations at λ<68 nm. We show that the observed lower 58.4 nm transmission is consistent with alternative optical constants derived from previous lab measurements.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140026157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1117/1.jatis.10.1.014004
Xing Fu, Yu Lei, Hua Li, Kewei E., Peng Wang, Junpeng Liu, Yuliang Shen, Dongguang Wang
Accurate infrared magnetic system (AIMS) is a ground-based solar telescope with the effective aperture of 1 m. The system has complex optical path and contains multiple aspherical mirrors. Since some mirrors are anisotropic in space, parallel light undergoes complex spatial reflection after passing through the optical pupil. It is also required that part of the optical axis coincides with the mechanical rotation axis. The system is difficult to align. This article proposes two innovative alignment methods. First, a modularized alignment method is presented. Each module is individually assembled with optical reference reserved. System integration can be completed through optical reference of each module. Second, computer-aided alignment technology is adopted to achieve perfect wavefront. By perturbing the secondary mirror (M2), the influence of M2 position on the wavefront is measured and the mathematical relationship is obtained. Based on the measured wavefront data, the least squares method is used to calculate the M2 alignment and multiple adjustments have been made to M2. The final system wavefront has reached RMS=0.12 λ@632.8 nm. Through observations of stars and sunspots, it has been demonstrated that the optical system has good wavefront quality. The observed sunspot is clear with the penumbral and umbra discernible. The proposed method has been verified and provides an effective alignment solution for complex off-axis telescope with large aperture.
{"title":"Optical alignment technology for 1-meter accurate infrared magnetic system telescope","authors":"Xing Fu, Yu Lei, Hua Li, Kewei E., Peng Wang, Junpeng Liu, Yuliang Shen, Dongguang Wang","doi":"10.1117/1.jatis.10.1.014004","DOIUrl":"https://doi.org/10.1117/1.jatis.10.1.014004","url":null,"abstract":"Accurate infrared magnetic system (AIMS) is a ground-based solar telescope with the effective aperture of 1 m. The system has complex optical path and contains multiple aspherical mirrors. Since some mirrors are anisotropic in space, parallel light undergoes complex spatial reflection after passing through the optical pupil. It is also required that part of the optical axis coincides with the mechanical rotation axis. The system is difficult to align. This article proposes two innovative alignment methods. First, a modularized alignment method is presented. Each module is individually assembled with optical reference reserved. System integration can be completed through optical reference of each module. Second, computer-aided alignment technology is adopted to achieve perfect wavefront. By perturbing the secondary mirror (M2), the influence of M2 position on the wavefront is measured and the mathematical relationship is obtained. Based on the measured wavefront data, the least squares method is used to calculate the M2 alignment and multiple adjustments have been made to M2. The final system wavefront has reached RMS=0.12 λ@632.8 nm. Through observations of stars and sunspots, it has been demonstrated that the optical system has good wavefront quality. The observed sunspot is clear with the penumbral and umbra discernible. The proposed method has been verified and provides an effective alignment solution for complex off-axis telescope with large aperture.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140072573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1117/1.jatis.10.1.011209
Jonathan W. Arenberg, Tiffany Glassman, Elysia Starr, Reem Hejal, Till Liepmann, Charles Atkinson, Nina Altshuler, Annetta Luevano, Marc Roth, Perry Knollenberg
We formulate the lessons Northrop Grumman personnel have learned from their work on development of the James Webb Space Telescope. These lessons are strategic in nature and bear on the common behavior during development of all large complex systems, such as astrophysics missions, also known colloquially as Flagships. To justify the expense, a Flagship must be a large leap in scientific capability, demanding new architectures and technologies coupled with an intolerance to risk. We define “The Problem of Newness” based on our experience and data from Webb’s development. This unseen hand was present during Webb, and it is only in retrospect that we have been able to define it and present it as a lesson for the future. Future missions, Flagships in particular, should recognize the challenge of newness as a natural consequence of development and take steps to minimize its impact.
{"title":"Designing a new, large, complex observatory: learning the strategic lesson of newness from our experience on the James Webb Space Telescope","authors":"Jonathan W. Arenberg, Tiffany Glassman, Elysia Starr, Reem Hejal, Till Liepmann, Charles Atkinson, Nina Altshuler, Annetta Luevano, Marc Roth, Perry Knollenberg","doi":"10.1117/1.jatis.10.1.011209","DOIUrl":"https://doi.org/10.1117/1.jatis.10.1.011209","url":null,"abstract":"We formulate the lessons Northrop Grumman personnel have learned from their work on development of the James Webb Space Telescope. These lessons are strategic in nature and bear on the common behavior during development of all large complex systems, such as astrophysics missions, also known colloquially as Flagships. To justify the expense, a Flagship must be a large leap in scientific capability, demanding new architectures and technologies coupled with an intolerance to risk. We define “The Problem of Newness” based on our experience and data from Webb’s development. This unseen hand was present during Webb, and it is only in retrospect that we have been able to define it and present it as a lesson for the future. Future missions, Flagships in particular, should recognize the challenge of newness as a natural consequence of development and take steps to minimize its impact.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140148153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1117/1.jatis.10.1.014005
Christopher C. Stark, Natasha Latouf, Avi M. Mandell, Amber Young
A primary scientific goal of the future Habitable Worlds Observatory will be the direct detection and characterization of Earth-like planets. Estimates of the exoplanet yields for this concept will help guide mission design through detailed trade studies. It is therefore critical that yield estimation codes optimally adapt observations to the mission’s performance parameters to ensure accurate trade studies. To aid in this, we implement wavelength optimization in yield calculations for the first time, allowing the yield code to determine the ideal detection and characterization bandpasses. We use this capability to confirm the observational wavelength assumptions made for the large UV/Optical/IR surveyor, design B (LUVOIR-B) study, namely that the optimum detection wavelength is 500 nm for the majority of targets and the optimum wavelength to detect water is near 1000 nm, given LUVOIR-B’s assumed instrument performance parameters. We show that including the wavelength-dependent albedo of an Earth twin as a prior provides no significant benefit to the yields of exoEarth candidates and caution against tuning observations to modern Earth twins. We also show that coronagraphs whose inner working angles are similar to step functions may benefit from wavelength optimization and demonstrate how wavelength-dependent instrument performance can impact the optimum wavelengths for detection and characterization. The optimization methods we implement automate wavelength selection and remove uncertainties regarding these choices, helping to adapt the observations to the instrument’s performance parameters.
{"title":"Optimized bandpasses for the Habitable Worlds Observatory’s exoEarth survey","authors":"Christopher C. Stark, Natasha Latouf, Avi M. Mandell, Amber Young","doi":"10.1117/1.jatis.10.1.014005","DOIUrl":"https://doi.org/10.1117/1.jatis.10.1.014005","url":null,"abstract":"A primary scientific goal of the future Habitable Worlds Observatory will be the direct detection and characterization of Earth-like planets. Estimates of the exoplanet yields for this concept will help guide mission design through detailed trade studies. It is therefore critical that yield estimation codes optimally adapt observations to the mission’s performance parameters to ensure accurate trade studies. To aid in this, we implement wavelength optimization in yield calculations for the first time, allowing the yield code to determine the ideal detection and characterization bandpasses. We use this capability to confirm the observational wavelength assumptions made for the large UV/Optical/IR surveyor, design B (LUVOIR-B) study, namely that the optimum detection wavelength is 500 nm for the majority of targets and the optimum wavelength to detect water is near 1000 nm, given LUVOIR-B’s assumed instrument performance parameters. We show that including the wavelength-dependent albedo of an Earth twin as a prior provides no significant benefit to the yields of exoEarth candidates and caution against tuning observations to modern Earth twins. We also show that coronagraphs whose inner working angles are similar to step functions may benefit from wavelength optimization and demonstrate how wavelength-dependent instrument performance can impact the optimum wavelengths for detection and characterization. The optimization methods we implement automate wavelength selection and remove uncertainties regarding these choices, helping to adapt the observations to the instrument’s performance parameters.","PeriodicalId":54342,"journal":{"name":"Journal of Astronomical Telescopes Instruments and Systems","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140126555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-01DOI: 10.1117/1.jatis.10.1.018005
Vinooja Thurairethinam, Giorgio Savini, Gary Hawkins, Paolo Chioetto
Dichroic beamsplitters, or dichroics, rely on the optical interference that occurs within thin-film layers to ensure the separation of the transmission and reflection of selective wavelengths of an incident beam of light at a given angle of incidence. Utilized within the optical systems of numerous space telescopes, they act to separate the incoming light spectrally and spatially into various channels. As space missions increasingly demand simultaneous observations across wavebands spanning extreme wavelength ranges, the necessity for exceedingly complex broadband dichroics has emerged. Subsequently, the uncertainties pertaining to their optical performance have also become more intricate. We use transmission line modeling to evaluate the spectral performance of multilayer coatings deposited on a substrate material for given thicknesses, materials, angles of incidence, and polarization. A dichroic recipe in line with the typical specifications and requirements of a dichroic is designed with the aid of a Monte Carlo simulation. The tolerances of the coating performance to systematic and random uncertainties from the manufacturing process, as well as from environmental changes in space, are studied. With the aid of accurate manufacturing recipes and uncertainty amplitudes from commercial manufacturers, this tool can predict variations in the optical performance that result from the propagation of each of these uncertainties for various hypothetical scenarios and systematic effects.
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