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Table 1
List of known instrumental systematic effects in Planck-LFI.
| Effect | Source | Control/removal | Reference |
|
|
|||
| Effects independent of sky signal | |||
| White noise correlation | Phase switch imbalance ................. | Diode weighting ................. | 3.1.1 |
| 1/f noise ................. | RF amplifiers ................. | Pseudo-correlation and destriping ................. | 3.1.1 |
| Bias fluctuations | RF amplifiers, back-end electronics | Pseudo-correlation and destriping | 3.1.3 |
| Thermal fluctuations | 4 K, 20 K and 300 K thermal stages | Calibration, destriping | 3.1.2, 4.2.1 |
| 1 Hz spikes | Back-end electronics | Template fitting and removal | 3.1.4, 4.2.3 |
| Effects dependent on the sky signal | |||
| Main beam ellipticity | Main beams | Accounted for in window function | Planck Collaboration IV (2014) |
| Intermediate sidelobes | Optical response at angles | Masking of Galaxy and point | Not treated in this release |
| pick-up | < 5° from the main beam | sources | |
| Far sidelobes pick-up | Main and sub-reflector spillovers | Model sidelobes removed from timelines | 3.2.1, 4.3.1 |
| (not implemented in this release) | |||
| Bandpass asymmetries | Differential orthomode transducer | Spurious polarisation removal | Planck Collaboration II (2014) |
| and receiver bandpass response | |||
| Analogue-to-digital | Back-end analogue-to-digital | Template fitting and removal | 3.2.2, 4.3.2 |
| converter non linearity | converter | Planck Collaboration II (2014) | |
| Imperfect photometric | Sidelobe pick-up, radiometer noise | Calibration using the 4 K reference | 3.2.3, 4.3.3, |
| calibration | temperature changes and other | load voltage output | Planck Collaboration V (2014) |
| non-idealities | |||
| Pointing ................. | Uncertainties in pointing reconstru- | Negligible impact on temperature ................. | 3.3, 4.4 |
| ction, thermal changes affecting | anisotropy measurements | ||
| focal plane geometry | |||
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