degradation¶
- aiapy.calibrate.degradation(channel: Unit('Angstrom'), obstime, correction_table=None, calibration_version=None)[source]¶
Correction to account for time-dependent degradation of the instrument.
The correction factor to account for the time-varying degradation of the telescopes is given by a normalization to the calibration epoch closest to
obstime
and an interpolation within that epoch toobstime
,\[\frac{A_{eff}(t_{e})}{A_{eff}(t_0)}(1 + p_1\delta t + p_2\delta t^2 + p_3\delta t^3)\]where \(A_{eff}(t_e)\) is the effective area calculated at the calibration epoch for
obstime
, \(A_{eff}(t_0)\) is the effective area at the first calibration epoch (i.e. at launch), \(p_1,p_2,p_3\) are the interpolation coefficients for theobstime
epoch, and \(\delta t\) is the difference between the start time of the epoch andobstime
. All calibration terms are taken from theaia.response
series in JSOC or read from the table input by the user.Note
This function is adapted directly from the aia_bp_corrections.pro routine in SolarSoft.
- Parameters:
channel (
Quantity
) –obstime (
Time
) –correction_table (
Table
orstr
, optional) – Table of correction parameters or path to correction table file. If not specified, it will be queried from JSOC. Seeaiapy.calibrate.util.get_correction_table
for more information. If you are processing many images, it is recommended to read the correction table once and pass it with this argument to avoid multiple redundant network calls.calibration_version (
int
, optional) – The version of the calibration to use when calculating the degradation. By default, this is the most recent version available from JSOC. If you are using a specific calibration response file, you may need to specify this according to the version in that file.
See also
degradation
,aiapy.calibrate.get_correction_table
,aiapy.response.Channel.wavelength_response
,aiapy.response.Channel.eve_correction