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29 August 2022 An exposure time calculator for the Maunakea Spectroscopic Explorer
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Conference Poster
The Maunakea Spectroscopic Explorer (MSE) will convert the 3.6-m Canada-France-Hawaii Telescope (CFHT) into an 11.25-m primary aperture telescope with a 1.5 square degrees field-of-view at the prime focus. It will produce multi-object spectroscopy with a suite of low (R∼3,000), moderate (R∼6,000), and high (R∼40,000) spectral resolution spectrographs in optical and near-infrared bands that are capable of detecting over 4,000 objects per pointing. Generally, an exposure time calculator (ETC) should simulate a system performance by computing a signal-to-noise ratio (SNR) and exposure time based on parameters such as a target magnitude, a total throughput of the system, and sky conditions, etc. The ETC that we have developed for MSE has individual computation modes for SNR, exposure time, SNR as a function of AB magnitude, and SNR as a function of wavelength. The code is based on an agile development methodology and allows for a variety of user input. Users must select either LR, MR, or HR spectral resolution settings in order to pull the associated MSE instrument parameters. Additionally, users must specify the target and background sky magnitudes (and have the ability to alter the default airmass and water vapor values). The software is developed with Python 3.7, and Tkinter graphical user interface is implemented to facilitate cross-platform use. In this paper, we present the logic structure and various functionalities of our MSE-ETC, including a software design and a demonstration.
© (2022) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Tae-Geun Ji, Taeeun Kim, Changgon Kim, Hojae Ahn, Mingyeong Yang, Soojong Pak, Sungwook E. Hong, Jennifer E. Sobeck, Kei Szeto, Jennifer L. Marshall, and Christian Surace "An exposure time calculator for the Maunakea Spectroscopic Explorer", Proc. SPIE 12189, Software and Cyberinfrastructure for Astronomy VII, 121892N (29 August 2022);

Spectral resolution

Signal to noise ratio


Optical fibers

Data modeling



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