httm.data_structures.electron_flux_converter

This module contains data structures for dealing with converting electron flux images to raw images.

class SingleCCDElectronFluxConverter[source]

An immutable object for managing a transformation from a electron flux FITS image into a simulated raw image.

Parameters:
class SingleCCDElectronFluxConverterFlags[source]

Flags indicating which raw transformations have been performed.

Parameters:
  • smear_rows_present (bool) – Flag indicating whether there is data in the smear rows. Default: False
  • shot_noise_present (bool) – Flag indicating whether shot noise is present. Default: False
  • blooming_present (bool) – Flag indicating whether blooming has been simulated. Default: False
  • readout_noise_present (bool) – Flag indicating whether readout noise is present. Default: False
  • undershoot_present (bool) – Flag indicating whether undershoot is present or otherwise compensated for. Default: False
  • start_of_line_ringing_present (bool) – Flag indicating whether start of line ringing is present or otherwise compensated for. Default: False
  • pattern_noise_present (bool) – Flag indicating whether pattern noise is present or otherwise compensated for. Default: False
  • baseline_present (bool) – Flag indicating whether a baseline electron count is present or otherwise compensated for. Default: False
  • in_adu (bool) – Flag indicating whether the data is in Analogue to Digital Converter Units or otherwise in electron counts. Default: False
class SingleCCDElectronFluxConverterParameters[source]

Converter parameters for converting a electron flux FITS image into a simulated raw FITS image.

Constructed using electron_flux_converter_from_fits() or electron_flux_converter_from_hdulist().

Parameters:
  • number_of_slices (int) – The number of slices to use in the transformation, either 1 or 4. Default: 4
  • camera_number (int) – The number of the camera that took the image. For real images, the serial number 0-31 of the FPE interface board is used. Default: -1
  • ccd_number (int) – The number of the CCD that took the image. Default: -1
  • number_of_exposures (int) – The number of frames stacked in the image. Default: 1
  • video_scales (tuple of float objects, must have one for each slice) – The video scaling constants, for converting back and forth between Analogue to Digital Converter Units (ADU) to electron counts. These have units of electrons per ADU. Default: (5.5, 5.5, 5.5, 5.5)
  • readout_noise_parameters (tuple of float objects, must have one for each slice) – The video readout noise standard deviation in electrons. Corresponds to fluctuations in electron counts for completely dark pixel data. Default: (9.5, 9.5, 9.5, 9.5)
  • early_dark_pixel_columns (int) – Count of columns of pixels that have never traversed the image area or frame store, and thus were never exposed to light. Read before the image pixels in the row, these are where most of the start of line ringing may be seen. Default: 11
  • late_dark_pixel_columns (int) – Count of columns of pixels that have never traversed the image area or frame store, and thus were never exposed to light. Read after the image pixels in a row. Default: 11
  • final_dark_pixel_rows (int) – Count of rows of pixels that have traversed the frame store area, but not the image area, and thus were never exposed to light. Default: 10
  • smear_rows (int) – Count of rows of pixels that have traversed the imaging area during frame transfer, but have zero exposure to light otherwise. These are for estimating the effect of smear on the imaging pixels. Default: 10
  • random_seed (int) – The pseudo random number generator seed. The default value of -1 creates a seed from the system clock. Default: -1
  • full_well (float) – The expected maximum number of electrons that a pixel can hold. Default: 170000.0
  • blooming_threshold (float) – The expected maximum number of electrons before a pixel blooms. Default: 140000.0
  • gain_loss (float) – The relative decrease in video gain over the total ADC range. This is the parameter of the non-linearity model. This is sometimes referred to as compression in electrical engineering literature. Default: 0.01
  • undershoot_parameter (float) – The deficit in a pixel value relative to the value of its preceding pixel. This is a ratio and dimensionless. The electronics have a slight memory of the signal level which cause the pixel following a bright pixel to appear slightly darker that it should. Default: 0.0013
  • single_frame_baseline_adus (float) – The mean ADU for a pixel with zero electrons for a single simulated frame exposure, per slice. Default: (6000.0, 6000.0, 6000.0, 6000.0)
  • single_frame_baseline_adu_drift_term (float) – Standard deviation of a random number added to the single frame baseline adu parameter per simulated frame (same for all slices). Default: 0.0
  • smear_ratio (float) – The time that a charge packet spends in transit through each imaging pixel that it does not nominally belong to, relative to the time it spends in the pixel it does nominally belong to. Used for simulating smear rows. Default: 4.84836e-06
  • clip_level_adu (int) – The level in ADU where the CCD or the electronics will clip the video. The default is the maximum the Analogue to Digital Converter (ADC) can deliver. Default: 65535
  • start_of_line_ringing (str) – A vector to be read from an npz file, to be added to each row in of a slice, representing the repeatable change in the video baseline caused by the disturbance in the data acquisition rhythm between rows. Units of the array are electrons. Default: built-in default_start_of_line_ringing.npz
  • pattern_noise (str) – A matrix to be read from a FITS file (either uncompressed or compressed with gzip, bzip2, or pkzip), representing the repeatable change in the video baseline caused by the disturbance in the data acquisition rhythm between frames. Organized as a RAW FFI (including dark pixels and smear rows), in Analogue to Digital Converter Units (ADU). Default: built-in simulated_pattern_noise.fits