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TMT Imaging ETC (under construction)

For details of the calculation, see TMT ETC Readme page.
Please direct the enquiries about TMT ETC to mariko.kubo_at_nao.ac.jp (change _at_ to @).
Basic parameters of TMT first generation instruments (imaging mode)
Wavelength coverage (μm) 0.8 – 2.4 0.31 - 1.0 0.95 - 2.45
Field of view 17".2 x 17".2 8'.3 x 3'.0 2' x 2'
Detector Hawaii-4RG
(4K x 4K pix)
Unreleased Hawaii-2RG
(2K x 2K pix)
Pixel scale (mas/pix) 4 52 60
Typical FWHM of PSF (mas) 8 with AO
600 w/o AO
800 8 with AO
600 w/o AO
Read out noise
(electrons/pixel in rms)
2 3 15
Dark current (electrons/sec/pixel) 0.002 0.0003 0.01?
Total throughput (%) ~44-52 with AO ~27 ~30-40 with AO

Source Geometry:
Aperture radius to calculate S/N = FWHM x
Extract square region of size = x arcsecond2

Point Spread Function:
Seeing size: mas

Target Brightness:
= mag for point source
= mag/arcsecond2 for extended source

Sky Condition:
Observatory Site:
Lunar Phase Angle: degree
Angular distance between moon and target: degree

System Configuration:
Use instrument parameters for
Telescope Diameter: m
Pixel scale: mas/pixel
Read out noise: electrons/pixel in rms
Dark current: electrons/sec/pixel
Total efficiency: including both optics efficiency and instrumental quantum efficiency

Output Format:
second on source x frames