WISE Flight System Idiosyncracies Relevant to Data Processing
                     Frank Masci, v. 2.1, 01/01/2010


Both pre-flight expectations from ground characterization, speculations, and 
post-flight findings are listed below. There is a code at the end of each 
item to indicate its origin:

 [P] = pre-flight finding or expectation
 [F] = confirmed post-flight or new finding
 [S] = pure speculation or unknown
 [P,F] = both [P] and [F] above

A pictorial gallery of detector idiosyncrasies is posted here.

This document is organized as follows:

  A. Detector/Electronic Properties
  B. Image/Optical-System Properties
  C. Spacecraft Maneuver/PCS Features


A. Detector/Electronic Properties
---------------------------------

(1) Detector Bad Pixels
    - W1/2 bad pixels evolve with thermal cycles [P,F]
    - bad-pixel transients in general: timescales, stability? [P]
    - popcorn noise? [P]
    - Build up of low/high response pixels in W3/4 as a result of radiation 
      damage (e.g., SAA passages) [S]

(2) Detector (fixed frequency / variable phase) pattern noise - all bands:
    - Odd/Even column (amplifier-dependent) patterns in W1/2? [P,F]
    - Corrugation patterns? [P,F]

(3) Si:As Detector Banding
    - DC level shifts in rows/cols at hot pixels in W3, W4 (banding) [P,F]

(4) Detector Linearity - surprisingly large [P]

(5) Latents:
    - Suppression following anneals [P,F]
    - Parent source color dependence? [S]
    - Parent source flux dependence, including saturation? [P,F]
    - Cosmic ray latents - yes: IOC analysis => saturated cores of
      CR hits give latents in subsequent frame only [F]

(6) Post anneal behavior:
    - exponential decay of response proportional to temperature 
      decay and stabilizing after about 15 minutes? [P]
    - drifts in response as temperature settles over about 3 
      hours [P]
    - unexplained upward response drift in W3 (2% in 2 hours) in 
      one MIC-2 test? [P]
    - Dark/Response settling [S] 
    - temperature equilibration following anneals [P,F]

(7) W3/4 droop:
    - dependence on amplifier quadrant? [P,F]
    - dependence with "bad-pixel banding" region [P,F]
    - non-saturating and/or just saturating signals? [P]
    - gain or offset effect? [S]

(8) Saturation induced idiosyncrasies:
    - dark rings and their decay (all bands), quadrant dependence? [P]
    - column pulldown [S]
    - muxbleed [S]

(9) Output channel temporal variations/noise:
    - e.g., ch.14 in w1 L0's; ch.15 in w2 L0's following
      IOC dark and read-noise analysis [P,F]

(10) High energy cosmic rays appearing extended and source-like
     - secondary showers [F]
     - frequency of occurence? [S]
     - impact on single frame source extraction? [S]


B. Image/Optical-System Properties
----------------------------------

(1) Discrepancy between predicted and measured RSR [S]

(2) PSF focal-plane position dependence due to
    - FOV distortion [P,F]
    - aberrations [S]
    - scan mirror non-linearity [S]

(3) Ghosting - in W3/4 seen in MIC2 and flight data [P,F]

(4) stray light (as seen in MIC2 droop test) [P,F?]

(5) glints [F]

(5) Source halos from internal self-reflections? [S]

(6) W3/4 measles, in MIC2 only? [P,F]

(7) Dust specs on any optical elements, including scan mirror? [S]

(8) Low-frequency responsivity variations, throughput stability? [S]


Spacecraft Maneuver/PCS Features
--------------------------------

(1) Spacecraft drifts during scans and frame exposures: 
    - impacts on image quality, PSF? [S]

(2) Spacecraft drift/settling following maneuvers, and mid-scan [P,F]