chandra_aca.dark_subtract¶
- chandra_aca.dark_subtract.get_aca_images_bgd_sub(img_table, t_ccd_vals, img_dark, tccd_dark)[source]¶
Get the background subtracted ACA images.
- Parameters:
- img_tableastropy.table.Table
Table of ACA images with columns ‘IMG’, ‘IMGROW0_8X8’, ‘IMGCOL0_8X8’, ‘INTEG’.
- t_ccd_valsnp.array
CCD temperature values at the times of the ACA images (deg C).
- img_darknp.array
Dark calibration image. Must be 1024x1024 (e-/s).
- tccd_darkfloat
Reference temperature of the dark calibration image (deg C).
- Returns:
- tuple (imgs_bgsub, imgs_dark)
- imgs_bgsubnp.array
Background subtracted ACA images (DN).
- imgs_darknp.array
Dark current images (DN).
- chandra_aca.dark_subtract.get_dark_backgrounds(raw_dark_img, imgrow0, imgcol0, size=8)[source]¶
Get dark background cutouts at a set of ACA image positions.
- Parameters:
- raw_dark_imgnp.array
Dark calibration image.
- imgrow0np.array (int)
Row of ACA image.
- imgcol0np.array (int)
Column of ACA image.
- sizeint, optional
Size of ACA image (default=8).
- Returns:
- imgs_darknp.array (len(imgrow0), size, size)
Dark backgrounds for image locations sampled from raw_dark_img (e-/s). Pixels outside raw_dark_img are set to 0.0.
- chandra_aca.dark_subtract.get_dark_current_imgs(img_table, img_dark, tccd_dark, t_ccds)[source]¶
Get the scaled dark current values for a table of ACA images.
This scales the dark current to the appropriate temperature and integration time, returning the dark current in DN matching the ACA images in img_table.
- Parameters:
- img_tableastropy.table.Table
Table of ACA images with columns ‘IMG’, ‘IMGROW0_8X8’, ‘IMGCOL0_8X8’, ‘INTEG’.
- img_dark1024x1024 array
Dark calibration image.
- tccd_darkfloat
Reference temperature of the dark calibration image.
- t_ccdsarray
Cheta temperature values at the times of img_table.
- Returns:
- imgs_darknp.array (len(img_table), 8, 8)
Temperature scaled dark current for each ACA image in img_table (DN).
- chandra_aca.dark_subtract.get_tccd_data(times, smooth_window=30, median_window=3, source='maude', maude_channel=None)[source]¶
Get the CCD temperature for given times and interpolate and smooth.
This is a light wrapper around cheta.fetch_sci.Msid(“aacccdpt”, start, stop) to handle an option to use the maude data source in an explicit way.
- Parameters:
- times: np.array (float)
Sampling times for CCD temperature data (CXC seconds).
- sourcestr, optional
Source of CCD temperature data (‘maude’ (default) or ‘cxc’ for cheta archive).
- median_windowint, optional
Median filter window to remove outliers (default=3).
- smooth_windowint, optional
Smooth data using a hanning window of this length in samples (default=30).
- maude_channelstr, optional
Maude channel to use (default is flight).
- Returns:
- valsnp.array
CCD temperature values.