ICID 12 => LONG_DARK_UNBINNED_SHORTDURATION

Illumination:

  • Dark.

Purpose:

  • Unbinned long-duration dark measurement.
  • Determination / monitoring of pixel dark current.
  • Monitoring of bad and dead detector pixels.

Location:

  • Eclipse side of the orbit.

Usage:

  • From launch onwards, once per day.
  • As a result of an anomaly in the Folding Mirror Mechanism (FMM) no ICID 12 measurements were performed from 28 February 2006 up to (including) 11 June 2006, with only one measurement at 6 June 2006. After this period the anomaly was resolved and the regular measurement schedule of one measurement per day was resumed.

Description:

Unbinned long-duration dark calibration measurement. These unbinned measurements are well suited to determine / monitor the unbinned detector bad and dead pixels and the dark current of the individual pixels. The ICID 12 measurements are the long-duration dark measurements with a comparatively short exposure time. The measurements are used together with the long-duration dark measurements with a comparatively long exposure time of ICID 13. On 9 March 2005 (orbit number 3457) 2 more long-duration unbinned dark measurements were added: ICIDs 141 and 142. These are similar to ICIDs 12 and 13, but they have lower electronic gain factors to avoid potential saturation. ICID 103 is an unbinned long-duration dark measurement with an intermediate exposure time. This ICID 103 was added to the daily measurement scenario on 9 March 2005 (orbit number 3458) in order to study the proton radiation effects in the South Atlantic Anomaly (SAA) in the vicinity of Brazil. The dark measurements of ICID 12 are performed with the Folding Mirror Mechanism (FMM) in the position that blocks the Earth optical path. The dark measurements are stored in the level-1b calibration data product.