Abstract The next generation of imaging surveys, including the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), Euclid, and the Nancy Grace Roman Space Telescope, will provide unprecedented constraints on cosmology using weak gravitational lensing. To fully exploit this statistical power, shear measurement methods must achieve sub-percent accuracy while mitigating systematic biases from noise, the point-spread function (PSF), blending, and shear-dependent detection. The analytical calibration framework (AnaCal) has demonstrated such accuracy but requires adding noise to images, reducing effective depth. We introduce Deep-Field Analytical Calibration (deep-fieldAnaCal), an extension of AnaCal that uses deep-field images to compute shear responses while preserving the statistical power of wide-field data. We validate deep-fieldAnaCal on isolated and blended galaxy image simulations with LSST-like conditions, finding it meets the stringent requirement of multiplicative bias |m| 3 × 10−3 at 99.7percnt confidence. Compared to standard AnaCal applied to wide-field images, deep-fieldAnaCal increases the effective galaxy number density from 17 to 30 arcmin−2 for simulated 10-year LSST data. With deep fields 10 × longer than the wide field, we find pixel noise variance in shear estimation is reduced by 30 % and overall uncertainty by ∼25 %. Finally, using the LSST Deep Drilling Fields strategy, we assess sample variance and find an equivalent calibration uncertainty of ≲ 0.3 %. These results demonstrate that deep-fieldAnaCal offers a promising path to achieve the required shear calibration for upcoming weak lensing surveys.
Park et al. (2026) studied this question.