Module dark_models

Define models to represent the observed ACA CCD dark current distribution. Provide a function to degrade the CCD for a delta time.

Functions

[hide private]

broken_pow(pars, x)
Broken power-law.

source code

smooth_broken_pow(pars, x)
Smoothed broken power-law.

source code

smooth_twice_broken_pow(pars, x)
Smoothed broken power-law.

source code

zero_dark_ccd()

source code

pristine_ccd()
Generate and return a 'pristine' (zero-year) dark current map.

source code

nompars(dyear)
Return nominal degradation parameters for dyear interval

source code

degrade_ccd(dark, dyear)
Degrade CCD (dark current map) for dyear years.

source code

temp_scalefac(T_ccd)
Return the multiplicative scale factor to convert a CCD dark map from the nominal -19C temperature to the temperature T.

source code

Variables

[hide private]

dx = 0.1

sigma = 0.25

xg = array([-0.625, -0.525, -0.425, -0.325, -0.225, -0.125, -0...

yg = array([ 0.00707646, 0.01775689, 0.03796914, 0.06918429...

NPIX = 1048576

xall = array([ 2.12201845e+00, 2.38094387e+00, 2.67146296...

imin = 0

imax = 79

Function Details

[hide private]

broken_pow(pars, x)

source code

Broken power-law. Pars are same as bpl1d: 1: gamma1 2: gamma2 3: x_b (break point) 4: x_r (normalization reference point) 5: ampl1

smooth_broken_pow(pars, x)

source code

Smoothed broken power-law. Pars are same as bpl1d (NOT + gaussian sigma): 1: gamma1 2: gamma2 3: x_b (break point) 4: x_r (normalization reference point) 5: ampl1 # NOT 6: sigma (bins)

smooth_twice_broken_pow(pars, x)

source code

Smoothed broken power-law. Pars are same as bpl1d (NOT + gaussian sigma): 1: gamma1 2: gamma2 3: x_b (break point) 4: x_r (normalization reference point) 5: ampl1 # NOT 6: sigma (bins)

pristine_ccd()

source code

Generate and return a 'pristine' (zero-year) dark current map. This was empirically derived.

degrade_ccd(dark, dyear)

source code

Degrade CCD (dark current map) for dyear years. The input 'dark' map is updated in place.

temp_scalefac(T_ccd)

source code

Return the multiplicative scale factor to convert a CCD dark map from the nominal -19C temperature to the temperature T. Based on an overall reduction of 0.62 after changing from -15 to -19.

Variables Details

[hide private]

xg

Value:

array([-0.625, -0.525, -0.425, -0.325, -0.225, -0.125, -0.025,  0.075,
        0.175,  0.275,  0.375,  0.475,  0.575])

yg

Value:

array([ 0.00707646,  0.01775689,  0.03796914,  0.06918429,  0.10742295
,
        0.1421345 ,  0.16025621,  0.15397247,  0.126062  ,  0.08795047
,
        0.05228836,  0.02649017,  0.01143609])

xall

Value:

array([  2.12201845e+00,   2.38094387e+00,   2.67146296e+00,
         2.99743074e+00,   3.36317260e+00,   3.77354173e+00,
         4.23398345e+00,   4.75060757e+00,   5.33026936e+00,
         5.98066059e+00,   6.71041155e+00,   7.52920560e+00,
         8.44790763e+00,   9.47870826e+00,   1.06352856e+01,
         1.19329867e+01,   1.33890313e+01,   1.50227402e+01,
         1.68557917e+01,   1.89125094e+01,   2.12201845e+01,
         2.38094387e+01,   2.67146296e+01,   2.99743074e+01,
...