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Table 1
List of known instrumental systematic effects in Planck-LFI.
| Effect | Source | Control/Removal | Reference |
| Effects independent of the sky signal (temperature and polarization) | |||
| White noise correlation | Phase switch imbalance | Diode weighting | Planck Collaboration III (2014) |
| 1/f noise | RF amplifiers | Pseudo-correlation and destriping | Planck Collaboration III (2014) |
| Bias fluctuations | RF amplifiers, back-end electronics | Pseudo-correlation and destriping | Sect. 3.2.5 |
| Thermal fluctuations | 4-K, 20-K and 300-K thermal stages | Calibration, destriping | Sect. 3.2.4 |
| 1-Hz spikes | Back-end electronics | Template fitting and removal | Sect. 3.2.6 |
| Effects dependent on the sky signal (temperature and polarization) | |||
| Main beam ellipticity | Main beams | Accounted for in window function | Planck Collaboration III (2016) |
| Near sidelobe | Optical response at angles <5° | Masking of Galaxy and point sources | Planck Collaboration II (2016), |
| pickup | from the main beam | Sects. 2.1.2, 3.2.1 | |
| Far sidelobe pickup | Main and sub-reflector spillover | Model sidelobes removed from timelines | Sects. 2.1.1, 3.2.1 |
| Analogue-to-digital | Back-end analogue-to-digital | Template fitting and removal | Sect. 3.2.3 |
| converter nonlinearity | converter | ||
| Imperfect photometric | Sidelobe pickup, radiometer noise | Adaptive smoothing algorithm using 4π | Planck Collaboration II (2016), |
| calibration | temperature changes, and other | beam, 4-K reference load voltage output, | Sects. 2.2, 3.2.2 |
| non-idealities | temperature sensor data | ||
| Pointing | Uncertainties in pointing reconstru- | Negligible impact on anisotropy | Sects. 2.1, 3.2.1 |
| ction, thermal changes affecting | measurements | ||
| focal plane geometry | |||
| Effects specifically impacting polarization | |||
| Bandpass asymmetries | Differential orthomode transducer | Spurious polarization removal | Sect. 2.3 |
| and receiver bandpass response | |||
| Polarization angle | Uncertainty in the polarization | Negligible impact | Sects. 2.1.3, 3.2.1 |
| uncertainty | angle in-flight measurement | ||
| Orthomode transducer | Imperfect polarization separation | Negligible impact | Leahy et al. (2010) |
| cross-polarization | |||
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