SLIDE 1
- Characterization of CCD based shear
systematics
- Systematics suppression via ISR and
- bserving strategy
- Validation via simulations
- Dither schemes and ComCam validation
Correcting sensor based PSF ellipticity Tony Tyson Steps - - PowerPoint PPT Presentation
Correcting sensor based PSF ellipticity Tony Tyson Steps - - PowerPoint PPT Presentation
Correcting sensor based PSF ellipticity Tony Tyson Steps Characterization of CCD based shear systematics Systematics suppression via ISR and observing strategy Validation via simulations Dither schemes and ComCam validation
SLIDE 2
SLIDE 3
SRD goals for shear systematics reduction
SLIDE 4
Brighter-fatter xy assymetry
Craig Lage 2018
SLIDE 5
In some ITL segments
Serial register deferred charge
Craig Lage 2018
SLIDE 6
In some ITL segments
Serial register deferred charge
Andrew Bradshaw 2018
SLIDE 7
Don’t average down like root 1/N_fields. Suppress by factor of 30 via two steps:
- Pixel pipeline processing correction
- Camera rotation dithering
CCD B-F & serial anisotropies
SLIDE 8
Application of ISR kernel correction
ISR and residuals
Andrew Bradshaw 2018
SLIDE 9
Shear systematic imprinted on sky
100 rotation dithers James Jee + TT 2015 WL Workshop
SLIDE 10
Shear systematic imprinted on sky
Science-Driven Optimization of the LSST Observing Strategy
1708.04058 Ch9 Josh Meyers & TT
SLIDE 11
- Need uniform distribution of PSF ellipticity over
all visits to a field
- Requires camera rotator span -90 to +90 deg
- But not uniformly! Weather, seeing variations.
- Sets Observatory Scheduler requirements
- Validate dithering scheme early with ComCam