synopsis: (1) reduction of statistical uncertainty by removing outliers, (2) increase of statistical uncertainty due to decrease of effective integration time.
limitations and applicability:
For measurements with less than 22 signals per chopper plateau or per
raster point the iterative method is not used, instead all signals with
V/s are removed.
description:
The distribution of a number of consecutive signals
(=local distribution) is analyzed and outliers are removed
according to a kappa-sigma criterion. This is repeated several times.
purpose correction:
Removal of signal glitches/outliers that are not recognized during
ramp deglitching (Sect. 3.4).
uncertainty/noise introduced:
None, reduces the statistical uncertainty.
auxillary data:
see Table 2
Parameter | Value | Description |
min_deglitch | 5 | minimum points to apply |
max_error | 1 V/s | maximum error allowed if number of |
points is less than min_deglitch | ||
n_iter | 2 | number of iterations of deglitch filter |
n_local | 20 | number of points in local distribution |
n_step | 1 | the number of points to move the `box' |
for the local distribution each time | ||
n_sigma | 3 | Rejection factor: number of standard |
deviations from local median. | ||
n_bad | 2 | number of times point has to be flagged |
as `bad' before it is rejected. |
Keyword(s):
MINDEG: | Min points for deglitcher | SPD header |
MAXERR: | Max error if points < MINDEG | SPD header |
NITERATE: | No. of iterations of deglitcher | SPD header |
NLOCAL: | No. of local points used by deglitcher | SPD header |
NSTEP: | Deglitcher step size | SPD header |
NSIGMA: | amount rms from local median | SPD header |
NBAD: | badness count limit | SPD header |
P??NSIG : | number of valid signals on plateau (??=P1,P2,P3,C1,C2) | (SPD record) |