A cross-calibration approach for polarisation-sensitive detectors in CMB experiments: application to LiteBIRD's polarisation angle calibration

@misc{novelli2026crosscalibration,
  title = {{A cross-calibration approach for polarisation-sensitive detectors in CMB experiments: application to LiteBIRD's polarisation angle calibration}},
  author = {A. Novelli and F. Piacentini and S. Micheli and E. Allys and A. Anand and J. Aumont and A. J. Banday and R. B. Barreiro and N. Bartolo and S. Basak and A. Basyrov and A. Besnard and D. Blinov and M. Bortolami and T. Brinckmann and F. Cacciotti and E. Calabrese and P. Campeti and A. Carones and F. Carralot and F. J. Casas and J. Chandran and K. Cheung and M. Citran and L. Clermont and F. Columbro and A. Coppolecchia and F. Cuttaia and P. de Bernardis and T. de Haan and E. de la Hoz and M. De Lucia and P. Diego-Palazuelos and H. K. Eriksen and F. Finelli and C. Franceschet and U. Fuskeland and G. Galloni and M. Galloway and M. Gerbino and M. Gervasi and R. T. Génova-Santos and T. Ghigna and S. Giardiello and C. Gimeno-Amo and A. Gruppuso and M. Hazumi and S. Henrot-Versillé and L. T. Hergt and E. Hivon and H. Ishino and K. Kohri and L. Lamagna and M. Lattanzi and C. Leloup and F. Levrier and A. I. Lonappan and M. López-Caniego and G. Luzzi and J. Macias-Perez},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2606.23207},
  eprint = {2606.23207},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2606.23207},
}

TY  - UNPB
TI  - A cross-calibration approach for polarisation-sensitive detectors in CMB experiments: application to LiteBIRD's polarisation angle calibration
AU  - A. Novelli
AU  - F. Piacentini
AU  - S. Micheli
AU  - E. Allys
AU  - A. Anand
AU  - J. Aumont
AU  - A. J. Banday
AU  - R. B. Barreiro
AU  - N. Bartolo
AU  - S. Basak
AU  - A. Basyrov
AU  - A. Besnard
AU  - D. Blinov
AU  - M. Bortolami
AU  - T. Brinckmann
AU  - F. Cacciotti
AU  - E. Calabrese
AU  - P. Campeti
AU  - A. Carones
AU  - F. Carralot
AU  - F. J. Casas
AU  - J. Chandran
AU  - K. Cheung
AU  - M. Citran
AU  - L. Clermont
AU  - F. Columbro
AU  - A. Coppolecchia
AU  - F. Cuttaia
AU  - P. de Bernardis
AU  - T. de Haan
AU  - E. de la Hoz
AU  - M. De Lucia
AU  - P. Diego-Palazuelos
AU  - H. K. Eriksen
AU  - F. Finelli
AU  - C. Franceschet
AU  - U. Fuskeland
AU  - G. Galloni
AU  - M. Galloway
AU  - M. Gerbino
AU  - M. Gervasi
AU  - R. T. Génova-Santos
AU  - T. Ghigna
AU  - S. Giardiello
AU  - C. Gimeno-Amo
AU  - A. Gruppuso
AU  - M. Hazumi
AU  - S. Henrot-Versillé
AU  - L. T. Hergt
AU  - E. Hivon
AU  - H. Ishino
AU  - K. Kohri
AU  - L. Lamagna
AU  - M. Lattanzi
AU  - C. Leloup
AU  - F. Levrier
AU  - A. I. Lonappan
AU  - M. López-Caniego
AU  - G. Luzzi
AU  - J. Macias-Perez
PY  - 2026
DA  - 2026/10/18
PB  - arXiv
DO  - 10.48550/arxiv.2606.23207
UR  - https://arxiv.org/abs/2606.23207
AB  - We present a cross-calibration algorithm that determines the relative calibration of detectors within the same frequency band of a CMB experiment. The method iteratively compares single-detector maps with frequency-band maps, and it can be applied to any calibration parameter that can be corrected through reprocessing of the instrument's data at the map level. This allows for validation and correction of calibration both before and after observations. We validate the pipeline by calibrating the polarisation angle of simulated sky maps from the upcoming \textit{LiteBIRD} experiment. The cross-calibration algorithm has been tested both in the case of random miscalibration of each individual detector and in the case of rotation of entire detector wafers. In both cases, the cross-calibration algorithm converges to the correct value and we are able to identify and correct relative miscalibrations in the polarisation angle of each detector with arcminute precision. Absolute calibration can then be addressed either through ground-based measurements, or through the E-B nulling technique. To assess compliance with \textit{LiteBIRD}'s systematics budget, we propagate the residual miscalibration uncertainties through component separation and tensor-to-scalar ratio (r) estimation pipelines using both parametric (\texttt{FgBuster}) and blind (\texttt{HILC}) methods. In both cases, the induced bias on r remains well below the \textit{LiteBIRD} maximum budget for systematics of δr < 6.5×10^−6. This confirms that the cross-calibration method presented is suited for use in modern high-precision CMB experiments.
ER  -