System Performance Metrics and Current Performance Status George Angeli

Performance Metrics * Calibration update in-progress Updated estimates

Integrated Étendue − Basic definition − Extended definition Sensitivity Integrated étendue -Fill Factor (f F ) - accounts for losses in the field due to masks, bad pixels, charge stops -Sensitivity Factor (f S ) – accounts for sensitivity losses or gains due to throughput, image quality, read noise -Observing Efficiency Factor (f O ) – accounts for losses or gains in open shutter efficiency over the entire survey

Sensitivity Factor Not allocated - driven by allocable Technical Performance Metrics: – Image Quality – Throughput – Read noise For each band: Overall f s as time weighted sum Observing band (filter) Time Allocation e2v mAR Depth Margin over SRD Des. fSfS u band 6.7 % g band 9.7 % r band22.3 % i band22.3 % z band19.4 % y band19.4 % Overall 1.185

Evolution of Image Depth Reserve Reserve in LSR above SRD Minimum Specification See Chuck’s presentation for details Sensitivity factor relative to SRD minimum specs: P R O P O S E D

Image Depth Dependencies For each band: Image Quality Throughput and read noise r band Change since JIM Review

Image Quality Error Budget milliarcsecond (mas) Telescope reserve: 105 mas Camera reserve: 102 mas See Bo’s presentation for details of meeting this budget

Evolution of IQ System Reserve Charge diffusion contribution estimate reduced before FDR from 259 mas to 186 mas milliarcsecond (mas)

System Behavior PSF size and shape

Integrated System Model PSF size and shape Currently ZEMAX Preferably PhoSim

Deterministic effects – Optical design residual errors, – Diffraction effects due to the finite aperture and pupil obscuration, Deterministic effects randomized by environmental and operational parameters – Mirror support print through and lens gravitational deformations randomized through telescope zenith angle – Thermal deformations of optical surfaces and support structures randomized through ambient and local temperature Random processes – Dome and mirror seeing – Local actuator and sensor noise and drift (non-optical sensors) – Counting statistics – CCD sensor effects (solid state effects: diffusion, field dependencies, penetration depth, QE variations) – WFS measurement, estimation, and control errors – Material, fabrication, and installation errors; these become deterministic once the “as built” system is available Input Parameters (Perturbations)

FWHM across the field Ellipticity across the field Output Parameters (Metrics) Area weighted mean of 31 samples – Diffraction (FFT) PSF – Also track geometric PSF derived from spot RMS

Fiducial atmospheres (3) – Scaled to 0.44”, 0.6”, and 0.8” FWHM seeing on the aperture of LSST. Zenith angle range of 0˚- 65˚ – Statistical distribution derived from “standard” OpSim simulations. Temperature and pressure ranges as defined in the OSS as Normal Operating Conditions. – The temperature inside enclosed volumes, like the Camera, needs to be estimated from these environmental parameters. The expected temperature range of the detector, with assumed statistics Environmental Conditions

Transition the optical kernel to PhoSim Include missing instrumental perturbations – Most prominently sensor effects – In the process of implemented in PhoSim Improve AOS control laws and performance Establish a configuration adequate for science simulations – Linked or emulated AOS Future Work