API and Modules

RECTE module

ramp effect model

Version 1.0.0: published version

Version 0.1: Adapted original IDL code (From D. Apai) to python by Yifan Zhou

RECTE.RECTE(cRates, tExp, exptime=180, trap_pop_s=0, trap_pop_f=0, dTrap_s=0, dTrap_f=0, dt0=0, lost=0, mode='scanning')[source]

This function calculates HST/WFC3/IR ramp effect profile based on the charge trapping explanation developed in Zhou et al. (2017).

param cRates:intrinsic count rate of each exposures, unit: e/s
type cRates:numpy.array
param tExp:time stamps for the exposures, unit: seconds
type tExp:numpy.array
param exptime:(default 180 seconds) exposure time
type exptime:numpy.array or float
param trap_pop_s:
 (default 0) number of occupied slow population charge traps before the very beginning of the observation
type trap_pop_s:
 float or numpy.array
param trap_pop_f:
 (default 0) number of occupied fast population charge traps before the very beginning of the observation
type trap_pop_f:
 float or numpy.array
param dTrap_s:(default [0]) number of additional charges trapped by slow population traps during earth occultation
type dTrap_s:float or numpy.array
param dTrap_f:(default [0]) number of additional charges trapped by fast population traps during earth occultation
type dTrap_f:float or numpy.array
param dt0:(default 0) exposure time before the very beginning of the observation. It could be due to guidence adjustment
type dt0:float
param lost:(default 0, no lost) fraction of trapped electrons that are not eventually detected
type lost:float
param mode:(default scanning, scanning or staring, or others), for scanning mode observation , the pixel no longer receive photons during the overhead time, in staring mode, the pixel keps receiving elctrons
type mode:string
returns:observed counts
rtype:numpy.array
Example:

see Examples and Cookbook

RECTECorrector module

RECTECorrector.RECTECorrector1(t, orbits, orbits_transit, counts, p, expTime, include_transit=False)[source]

correct the ackbar model for one directional scan observations

Parameters:
  • t – time stamps of the exposures
  • orbits – orbit number of the exposures
  • orbits_transit – orbits in which transits/eclipses occur
  • counts – observed counts
  • p – Parameters objects to fit
  • expTime – exposure time
Returns:

RECTE profile for correciting the light curve, best fit

count rate array, ackbar output, slope :rtype: tuple of four numpy array

RECTECorrector.RECTECorrector2(t, orbits, orbits_transit, counts, p, expTime, scanDirect)[source]

correct the ackbar model for one directional scan observations

Parameters:
  • t – time stamps of the exposures
  • orbits – orbit number of the exposures
  • orbits_transit – orbits in which transits/eclipses occur
  • counts – observed counts
  • p – Parameters objects to fit
  • expTime – exposure time
  • scanDirect – scan direction (0 or 1) for each exposure
Returns:

RECTE profile for correciting the light curve, best fit

count rate array, ackbar output, slope :rtype: tuple of four numpy array

RECTECorrector.rampProfile(crate, slope, dTrap_s, dTrap_f, trap_pop_s, trap_pop_f, tExp, expTime)[source]

Ramp profile for single directional scan

And RECTE model parameters: number of traps, trapping coeeficient and trap life time

Parameters:
  • crate – average count rate in electron/second
  • slope – visit-long slope
  • dTrap_s – extra trapped slow charges between orbits
  • dTrap_f – extra trapped fast charges between orbits
  • trap_pop_s – initially trapped slow charges
  • trap_pop_f – initially trapped fast charges
  • tExp – beginning of each exposure
  • expTime – exposure time
Returns:

observed counts
Return type:

numpy.array
RECTECorrector.rampProfile2(crate1, slope1, crate2, slope2, dTrap_s, dTrap_f, trap_pop_s, trap_pop_f, tExp, expTime, scanDirect)[source]

Ramp profile for bi-directional scan And ackbar model

Parameters:
  • crate1 – average count rate in electron/second for the upward direction
  • slope1 – visit-long slope for upward direction
  • crate2 – average count rate in electron/second for downward direction
  • slope2 – visit-long slope for downward direction
  • dTrap_s – extra trapped slow charges between orbits
  • dTrap_f – extra trapped fast charges between orbits
  • trap_pop_s – initially trapped slow charges
  • trap_pop_f – initially trapped fast charges
  • tExp – beginning of each exposure
  • expTime – exposure time
  • scanDirect – scan direction (0 or 1) for each exposure
Returns:

observed counts
Return type:

numpy.array