Systems engineering for the preliminary design of the Thirty Meter Telescope

Angeli, George Z.; Roberts, Scott; Vogiatzis, Konstantinos

doi:10.1117/12.787220

Cited by 17 publications

(17 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this paper, we find that the multiplicative feature is valid within a few percentages (within 2% for independent errors) when the science loss of all combined errors is smaller than 15% (i.e., the combined PSSN is larger than 85%). Since TMT has a requirement that the telescope should not introduce more than a 20% loss of science (the goal of the TMT that seeing-limited performance of the telescope achieves 80% of that of a perfect telescope is in terms of "science performance ratio," and its corresponding goal in terms of PSSN is around 0.85 [1,2]), we believe that this metric is useful for optical designing and budgeting errors of large, groundbased telescopes such as TMT.…”

Section: Discussionmentioning

confidence: 99%

“…The optical performance of an extremely large astronomical telescope, such as the Thirty Meter Telescope (TMT), is a major concern for the astronomers and engineers developing these next generation, ground based facilities [1,2]. While the design should be guided by the optimization of this performance, performance degradation should also be allocated among the various components of the observatory, i.e., an error budget should be established.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of normalized point source sensitivity as a performance metric for large telescopes

et al. 2009

View full text Add to dashboard Cite

We investigate a new metric, the normalized point source sensitivity (PSSN), for characterizing the seeing-limited performance of large telescopes. As the PSSN metric is directly related to the photometric error of background limited observations, it represents the efficiency loss in telescope observing time. The PSSN metric properly accounts for the optical consequences of wave front spatial frequency distributions due to different error sources, which differentiates from traditional metrics such as the 80% encircled energy diameter and the central intensity ratio. We analytically show that multiplication of individual PSSN values due to individual errors is a good approximation for the total PSSN when various errors are considered simultaneously. We also numerically confirm this feature for Zernike aberrations as well as for the numerous error sources considered in the error budget of the Thirty Meter Telescope (TMT) using a ray optics simulator. Additionally, we discuss other pertinent features of the PSSN, including its relations to Zernike aberration, RMS wave front error, and central intensity ratio.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of normalized point source sensitivity as a performance metric for large telescopes

et al. 2009

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4] It is known that this metric is directly related to the photometric error of background limited observations so that it accurately represents the efficiency loss of science due to increased telescope observing time. 4,5 The PSSN metric also properly accounts for the consequences of different spatial frequency distributions for various wavefront error sources, which makes it superior to traditional metrics such as the root mean square of the wavefront error (RMS WFE) for estimating seeing-limited errors.…”

Section: Introductionmentioning

confidence: 99%

Normalized point source sensitivity for off-axis optical performance evaluation of the Thirty Meter Telescope

et al. 2010

View full text Add to dashboard Cite

The Normalized Point Source Sensitivity (PSSN) has previously been defined and analyzed as an On-Axis seeing-limited telescope performance metric. In this paper, we expand the scope of the PSSN definition to include Off-Axis field of view (FoV) points and apply this generalized metric for performance evaluation of the Thirty Meter Telescope (TMT). We first propose various possible choices for the PSSN definition and select one as our baseline. We show that our baseline metric has useful properties including the multiplicative feature even when considering Off-Axis FoV points, which has proven to be useful for optimizing the telescope error budget. Various TMT optical errors are considered for the performance evaluation including segment alignment and phasing, segment surface figures, temperature, and gravity, whose On-Axis PSSN values have previously been published by our group.

show abstract

“…The PSSN is a recently developed performance metric that has been adopted for the Thirty Meter Telescope (TMT) and European Extremely Large Telescope for their error budgeting and performance evaluation [1][2][3][4]. This metric is directly related to the photometric error of background-limited observations so that it accurately represents the efficiency loss of science due to increased telescope observing time [5,6].…”

Section: Introductionmentioning

confidence: 99%

Estimation of normalized point-source sensitivity of segment surface specifications for extremely large telescopes

et al. 2013

View full text Add to dashboard Cite

We present a method which estimates the normalized point-source sensitivity (PSSN) of a segmented telescope when only information from a single segment surface is known. The estimation principle is based on a statistical approach with an assumption that all segment surfaces have the same power spectral density (PSD) as the given segment surface. As presented in this paper, the PSSN based on this statistical approach represents a worst-case scenario among statistical random realizations of telescopes when all segment surfaces have the same PSD. Therefore, this method, which we call the vendor table, is expected to be useful for individual segment specification such as the segment polishing specification. The specification based on the vendor table can be directly related to a science metric such as PSSN and provides the mirror vendors significant flexibility by specifying a single overall PSSN value for them to meet. We build a vendor table for the Thirty Meter Telescope (TMT) and test it using multiple mirror samples from various mirror vendors to prove its practical utility. Accordingly, TMT has a plan to adopt this vendor table for its M1 segment final mirror polishing requirement.

show abstract

Systems engineering for the preliminary design of the Thirty Meter Telescope

Cited by 17 publications

References 12 publications

Analysis of normalized point source sensitivity as a performance metric for large telescopes

Analysis of normalized point source sensitivity as a performance metric for large telescopes

Normalized point source sensitivity for off-axis optical performance evaluation of the Thirty Meter Telescope

Estimation of normalized point-source sensitivity of segment surface specifications for extremely large telescopes

Contact Info

Product

Resources

About