1.108. mkSidebandGain

Full Name: herschel.hifi.pipeline.generic.MkSidebandGainTask
Alias: mkSidebandGain
Type: Java Task - Java Task
Import: from herschel.hifi.pipeline.generic import MkSidebandGainTask
Category

HIFI/Pipeline/Level 2 Pipeline

Description

Creates an interpolator for computing the IF- and LO-frequency dependent sideband gains ratios.

The output is specified as an interface type (only the interface is needed by the {@link DoSidebandGainTask}-task). This will allow to include different implementations and provide the means to have them easily configured.

Example

Example 1: In HIPE
from herschel.hifi.pipeline.generic import MkSidebandGain
mkSidebandGain = MkSidebandGain()
gains = mkSidebandGain(htp=htp, shape=shapes)
gains = mkSidebandGain(htp=htp, method='level', level=levels)

API details

Properties

HifiTimelineProduct htp [INPUT, MANDATORY, default=no default value]

The input {@link HifiTimelineProduct} which is used to look up the detector band and the startDate of the observation. This is information is needed to look up the associated information from the 'level' and 'shape' calibration products passed as input parameters to the task (and typically retrieved from the calibration tree).

CalSidebandCoeff cal [OUTPUT, MANDATORY, default=no default value]

Helper object that is provided as output and allows to compute the sideband gains ratios. This object is passed as input parameter to the {@link DoSidebandGainTask}-task.

String method [INPUT, MANDATORY, default=no default value]

Two methods are available at the moment:

  • 'level': It is assumed that sideband gains do not vary across the IF frequency band but only have a LO dependent level. The levels are specified for selected LO frequency in the calibration table "sidebandGainLO-H" or "sidebandGainLO-V" (if "cal" is set) or in the table passed as "level" parameter. A linear interpolation scheme is adopted for intermediated LO frequencies. The calculation is delegated to {@link LevelCalSidebandCoeffImpl}.

  • 'shape': For selected LO frequencies suitable polynomial functions define the IF frequency dependency of the sideband gains. The coefficients for these functions are found in the calibration table "sidebandGainIF-H" or "sidebandGainIF-V" (if "cal" is set) or in the table passed as "shape" parameter. For intermediate LO frequencies the values defined by these polynomials are linearly interpolated (actually, truncuated linear). Method delegates to {@link PolynomialCalSidebandCoeffImpl}.

MapContext calibration [INPUT, OPTIONAL, default=no default value]

Reference to the calibration tree from which suitable tables for computing sideband gains are obtained.

GenericPipelineContext level [INPUT, OPTIONAL, default=no default value]

Calibration product that contains tables with the LO dependent gains coefficients level. Different tables correspond to different observation times (the observations have been taken at). This allows to account for potential instrument drifts.

GenericPipelineContext shape [INPUT, OPTIONAL, default=no default value]

The calibration product that contains tables with the polynomial coefficients to describe for selected LO frequencies the IF dependency of the gains coefficients. Different tables correspond to different observation times (the observations have been taken at). This allows to account for potential instrument drifts.

PipelineConfiguration params [INPUT, OPTIONAL, default=no default value]

Pipeline configuration parameters that can be passed to the task.

Boolean ignore [INPUT, OPTIONAL, default=no default value]

If set to True task is not executed.

See also

History

  • 2011-07-11 - Melchior: History added.
  • 2011-08-14 - Melchior: Renamed to MkSidebandGainTask.
  • 2013-10-21 - Melchior: Polynomial sideband gains (first version)
  • 2014-02-28 - Melchior: Polynomial sideband gains (second version)