SerialTrap¶

class lsst.ip.isr.SerialTrap(size, emission_time, pixel, trap_type, coeffs)¶

Represents a serial register trap.

Parameters:

size : float: Size of the charge trap, in electrons.
emission_time : float: Trap emission time constant, in inverse transfers.
pixel : int: Serial pixel location of the trap, including the prescan.
trap_type : str: Type of trap capture to use. Should be one of linear, logistic, or spline.
coeffs : list [float]: Coefficients for the capture process. Linear traps need one coefficient, logistic traps need two, and spline based traps need to have an even number of coefficients that can be split into their spline locations and values.

Raises:

Attributes Summary

`trap_array`
`trapped_charge`

Methods Summary

`capture`(pixel_signals)	Trap capture function.
`initialize`(ny, nx, prescan_width)	Initialize trapping arrays for simulated readout.
`release_charge`()	Release charge through exponential decay.
`trap_charge`(free_charge)	Perform charge capture using a logistic function.

Attributes Documentation

Methods Documentation

capture(pixel_signals)¶

Trap capture function.

Parameters:	pixel_signals : `list` [`float`] Input pixel values.
Returns:	captured_charge : `list` [`float`] Amount of charge captured from each pixel.
Raises:	RuntimeError Raised if the trap type is invalid.

initialize(ny, nx, prescan_width)¶

Initialize trapping arrays for simulated readout.

Parameters:	ny : `int` Number of rows to simulate. nx : `int` Number of columns to simulate. prescan_width : `int` Additional transfers due to prescan.
Raises:	ValueError Raised if the trap falls outside of the image.

release_charge()¶

Release charge through exponential decay.

Returns:	released_charge : `float` Charge released.

trap_charge(free_charge)¶

Perform charge capture using a logistic function.

Parameters:	free_charge : `float` Charge available to be trapped.
Returns:	captured_charge : `float` Amount of charge actually trapped.