Difference between revisions of "HFI-Validation"

From Planck Legacy Archive Wiki
Jump to: navigation, search
(Expected systematics and tests (bottom-up approach))
Line 30: Line 30:
 
* Saturation - While this is mostly an issue only for Jupiter observations, it should be remembered that the HFI detectors cannot observe arbitrarily bright objects. This is discussed in [[#Saturation|the section below on saturation]].
 
* Saturation - While this is mostly an issue only for Jupiter observations, it should be remembered that the HFI detectors cannot observe arbitrarily bright objects. This is discussed in [[#Saturation|the section below on saturation]].
  
 +
<!--
 
==Generic approach to systematics==
 
==Generic approach to systematics==
  
Line 191: Line 192:
 
We have used the SEB tool (standing for Simulation of Electronics and Bolometer) to simulate the response of the Readout Electronics Chain at a very high sampling, to mimic the high frequency behavior of the chain and investigate sub-period effects.
 
We have used the SEB tool (standing for Simulation of Electronics and Bolometer) to simulate the response of the Readout Electronics Chain at a very high sampling, to mimic the high frequency behavior of the chain and investigate sub-period effects.
 
It has been shown by this kind of simulations that the saturation of the ADC starts to appear if the signal is more then 7*10^5 - 8*10^5 ADU. Hence the variation of the gain, due to the saturation of the ADC, has an impact only when crossing Jupiter for SWB353GHz and SWB857GHz bolometers. This effect can be neglected.
 
It has been shown by this kind of simulations that the saturation of the ADC starts to appear if the signal is more then 7*10^5 - 8*10^5 ADU. Hence the variation of the gain, due to the saturation of the ADC, has an impact only when crossing Jupiter for SWB353GHz and SWB857GHz bolometers. This effect can be neglected.
 +
 +
-->
  
 
==References==
 
==References==

Revision as of 16:41, 29 January 2015


The HFI validation is mostly modular. That is, each part of the pipeline, be it timeline processing, map-making, or any other, validates the results of its work at each step of the processing, looking specifically for known issues. In addition, we do additional validation with an eye towards overall system integrity by looking at generic differences between sets of maps, in which most problems will become apparent, whether known or not. Both these are described below.

Expected systematics and tests (bottom-up approach)[edit]

Like all experiments, Planck/HFI had a number of "issues" which it needed to track and verify were not compromising the data. While these are discussed in appropriate sections, here we gather them together to give brief summaries of the issues and refer the reader to the appropriate section for more details.


References[edit]

(Planck) High Frequency Instrument

random telegraphic signal

Cosmic Microwave background

analog to digital converter