Glossary#
Within coronagraphs.py#
Variable Name |
Length |
Unit |
Meaning |
User Editable |
|---|---|---|---|---|
Istar |
[npix, npix] |
Dimensionless |
Star intensity distribution (on-axis PSF) |
No |
noisefloor |
[npix, npix] |
Dimensionless |
Noise floor of the coronagraph |
No |
photometric_aperture_radius |
Scalar |
λ/D |
Photometric aperture radius |
Yes |
psf_trunc_ratio |
Scalar |
Dimensionless |
truncate the off-axis PSF at a threshold (thresh = psf_trunc_ratio * max(off-axis PSF)) |
Yes |
photometric_aperture_throughput |
[npix, npix, npsfratios] |
Dimensionless |
fraction of light entering the coronagraph that ends up within the photometric core of the off-axis (planet) PSF assuming perfectly reflecting/transmitting optics, where the core is the solid angle area |
No |
omega_lod |
[npix, npix, npsfratios] |
(λ/D)² |
Solid angle of the photometric aperture |
No |
skytrans |
[npix, npix] |
Dimensionless |
Sky transmission; the coronagraph’s performance when observing an infinitely extended source |
No |
pixscale |
Scalar |
λ/D |
Pixel scale of the coronagraph model |
No |
npix |
Scalar |
Dimensionless |
length of one side of the coronagraph model images (assuming a square) |
No |
xcenter |
Scalar |
Pixel |
X-coordinate of the image center |
No |
ycenter |
Scalar |
Pixel |
Y-coordinate of the image center |
No |
bandwidth |
Scalar |
Dimensionless |
Fractional bandwidth of coronagraph |
Yes |
stellar_radius |
Scalar |
R_sun |
stellar radius in solar radii |
Yes |
stellar_angular_diameter_arcsec |
Scalar |
arcsec |
angular diameter of the star |
No |
npsfratios |
Scalar |
Dimensionless |
Number of PSF truncation ratios (default 1) |
No |
nrolls |
Scalar |
Dimensionless |
Number of roll angles performed |
Yes |
nchannels |
Scalar |
Dimensionless |
Number of channels in coronagraph |
Yes |
minimum_IWA |
Scalar |
λ/D |
Minimum Inner Working Angle |
Yes |
maximum_OWA |
Scalar |
λ/D |
Maximum Outer Working Angle |
Yes |
coronagraph_optical_throughput |
[nlambda] |
Dimensionless |
Throughput for all coronagraph optics |
Yes |
coronagraph_spectral_resolution |
Scalar |
Dimensionless |
Spectral resolution of the coronagraph |
Yes |
contrast |
Scalar |
Dimensionless |
Noise floor contrast of coronagraph |
Yes |
noisefloor_factor |
Scalar |
Dimensionless |
Systematic noise floor factor |
Yes |
noisefloor_PPF |
Scalar |
Dimensionless |
Noise floor post-processing factor |
Yes |
Tcore |
Scalar |
Dimensionless |
Core throughput of coronagraph (used in ToyModel only, or if photometric_aperture_radius is specified for omega_lod calculation) |
Yes |
TLyot |
Scalar |
Dimensionless |
Lyot transmission of the coronagraph (used in ToyModel only) |
Yes |
PSFpeak |
Scalar |
Dimensionless |
Peak value of the off-axis PSF |
No |
A note on calculating omega_lod:#
The photometric aperture omega_lod can be calculated via two methods, and the user should specify
either the psf_trunc_ratio or photometric_aperture_radius parameters to do so.
photometric_aperture_radiussimply sets a radius for the photometric aperture, such thatomega_lod = \pi * (photometric_aperture_radius * (lambda/D))^2, whereomega_lodis the solid angle of the photometric aperture.In contrast,
psf_trunc_ratiois a more complex way of calculating the photometric aperture solid angleomega_lod, necessary because the off-axis PSF is not always going to be a perfect circle, and can be misshapen. In principle, this method takes an off-axis PSF and calculatesomega_lodas all pixels in the PSF that are above the thresholdpsf_trunc_ratio * max(off-axis PSF), accounting for imperfect PSF shapes. Note: If the off-axis PSF shape is a perfect airy disk, thenpsf_trunc_ratiois simply1 - photometric_aperture_radius.Finally,
photometric_aperture_throughputis an entirely different, but related, parameter, not to be confused with the two parameters above. This parameter is essentially the core throughput of the off-axis PSF. In other words, this is the fraction of light entering the coronagraph that ends up within the photometric core of the off-axis (planet) PSF assuming perfectly reflecting/transmitting optics, where the core is the solid angle areaomega_lodand is set by eitherpsf_trunc_ratioorphotometric_aperture_radius.
Within telescopes.py#
Variable Name |
Length |
Unit |
Meaning |
User Editable |
|---|---|---|---|---|
diameter |
Scalar |
m |
Circumscribed diameter of telescope aperture |
Yes |
Area |
Scalar |
m^2 |
Effective collecting area of telescope |
No |
unobscured_area |
Scalar |
Dimensionless |
Unobscured area percentage |
Yes |
toverhead_fixed |
Scalar |
Time |
Fixed overhead time |
Yes |
toverhead_multi |
Scalar |
Dimensionless |
Multiplicative overhead time |
Yes |
telescope_optical_throughput |
[nlambda] |
Dimensionless |
Optical throughput of telescope |
Yes |
temperature |
Scalar |
Temperature |
Temperature of the warm optics |
Yes |
T_contamination |
Scalar |
Dimensionless |
Effective throughput factor for contamination |
Yes |
Within detectors.py#
Variable Name |
Length |
Unit |
Meaning |
User Editable |
|---|---|---|---|---|
pixscale_mas |
Scalar |
Milliarcsecond |
Detector pixel scale |
Yes |
npix_multiplier |
[nlambda] |
Dimensionless |
Number of detector pixels per image plane “pixel” |
Yes |
DC |
[nlambda] |
Electron / (Pixel * Second) |
Dark current |
Yes |
RN |
[nlambda] |
Electron / (Pixel * Read) |
Read noise |
Yes |
tread |
[nlambda] |
Second |
Read time |
Yes |
CIC |
[nlambda] |
Electron / (Pixel * Photon) |
Clock-induced charge |
Yes |
QE |
[nlambda] |
Electron / Photon |
Quantum efficiency of detector |
Yes |
dQE |
[nlambda] |
Dimensionless |
Effective QE due to degradation |
Yes |
Within observation.py#
Variable Name |
Length |
Unit |
Meaning |
User Editable |
|---|---|---|---|---|
wavelength |
[nlambda] |
um |
Observation wavelengths |
Yes |
SNR |
[nlambda] |
Dimensionless |
Signal-to-noise ratio |
Yes |
CRb_multiplier |
Scalar |
Dimensionless |
Factor to multiply assuming differential imaging to remove background |
Yes |
td_limit |
Scalar |
s |
Limit placed on exposure times |
No |
exptime |
[nlambda] |
s |
Exposure time for each wavelength |
No |
fullsnr |
[nlambda] |
Dimensionless |
Calculated SNR for each wavelength |
No |
observing_mode |
Scalar |
String |
Observing mode (e.g., ‘IMAGER’ or ‘IFS’) |
Yes |
Within astrophysical_scene.py#
Variable Name |
Length |
Unit |
Meaning |
User Editable |
|---|---|---|---|---|
dist |
Scalar |
pc |
Distance to star |
Yes |
vmag |
Scalar |
Magnitude |
Stellar magnitude at V band |
Yes |
mag |
[nlambda] |
Magnitude |
Stellar magnitude at desired wavelengths |
Yes |
stellar_angular_diameter_arcsec |
Scalar |
Arcsecond |
Angular diameter of star |
No |
nzodis |
Scalar |
Zodi |
Amount of exozodi around target star |
Yes |
ra |
Scalar |
Degree |
Right ascension of target star |
Yes |
dec |
Scalar |
Degree |
Declination of target star |
Yes |
semimajor_axis |
Scalar |
Astronomical Units |
Semimajor axis of the planet’s orbit (used to calculate separation; assumes face-on orbit) |
Yes |
separation |
Scalar |
Arcsecond |
Separation of planet |
Yes |
xp |
Scalar |
Arcsecond |
X-coordinate of planet (defaults to zero for now) |
No |
yp |
Scalar |
Arcsecond |
Y-coordinate of planet |
No |
deltamag |
[nlambda] |
Magnitude |
Magnitude difference between planet and host star |
Yes |
min_deltamag |
[nlambda] |
Magnitude |
Brightest planet to resolve at the IWA |
Yes |
F0V |
Scalar |
Photon / (s * cm² * nm) |
Flux zero point for V band |
Yes |
F0 |
[nlambda] |
Photon / (s * cm² * nm) |
Flux zero points for prescribed wavelengths |
Yes |
M_V |
Scalar |
Magnitude |
Absolute V band magnitude of target star |
No |
Fzodi_list |
[nlambda] |
Dimensionless |
Zodiacal light fluxes |
No |
Fexozodi_list |
[nlambda] |
Dimensionless |
Exozodiacal light fluxes |
No |
Fbinary_list |
[nlambda] |
Dimensionless |
Binary star fluxes |
No |
Fp_over_Fs |
[nlambda] |
Dimensionless |
Flux of planet relative to star |
Yes |
Fs_over_F0 |
[nlambda] |
Dimensionless |
Stellar flux relative to F0 |
No |
Within observatory.py#
Variable Name |
Length |
Unit |
Meaning |
User Editable |
|---|---|---|---|---|
optics_throughput |
[nlambda] |
Dimensionless |
Optical throughput of the entire system |
Yes* |
epswarmTrcold |
[nlambda] |
Dimensionless |
Warm emissivity * cold transmission factor |
Yes* |
total_throughput |
[nlambda] |
Dimensionless |
Total throughput including optics and detector |
No |
Within parse_input.py#
Variable Name |
Length |
Unit |
Meaning |
User Editable |
|---|---|---|---|---|
secondary_flag |
Scalar |
Boolean |
Flag for secondary variables |
Yes |
observatory_preset |
Scalar |
String |
Preset configuration for the observatory |
Yes |
telescope_type |
Scalar |
String |
Type of telescope to use |
Yes |
coronagraph_type |
Scalar |
String |
Type of coronagraph to use |
Yes |
detector_type |
Scalar |
String |
Type of detector to use |
Yes |
observing_mode |
Scalar |
String |
Observing mode (e.g., ‘IMAGER’ or ‘IFS’) |
Yes |
Within exposure_time_calculator.py#
Variable Name |
Length |
Unit |
Meaning |
User Editable |
|---|---|---|---|---|
deltalambda_nm |
Scalar |
nm |
Bandwidth for each wavelength |
No |
lod |
Scalar |
Dimensionless |
λ/D (wavelength / telescope diameter) |
No |
lod_rad |
Scalar |
Radian |
λ/D in radians |
No |
lod_arcsec |
Scalar |
Arcsecond |
λ/D in arcseconds |
No |
area_cm2 |
Scalar |
cm² |
Telescope collecting area |
No |
detpixscale_lod |
Scalar |
λ/D |
Detector pixel scale in λ/D units |
No |
stellar_diam_lod |
Scalar |
λ/D |
Stellar diameter in λ/D units |
No |
det_sep_pix |
Scalar |
Pixel |
Separation at IWA in pixels |
No |
det_sep |
Scalar |
Arcsecond |
Separation at IWA in arcseconds |
No |
det_Istar |
Scalar |
Dimensionless |
Max stellar intensity at IWA |
No |
det_skytrans |
Scalar |
Dimensionless |
Max sky transmission at IWA |
No |
det_photometric_aperture_throughput |
Scalar |
Dimensionless |
Max photometric aperture fraction at IWA |
No |
det_omega_lod |
Scalar |
(λ/D)² |
Solid angle corresponding to max photometric_aperture_throughput at IWA |
No |
det_npix |
Scalar |
Pixel |
Number of pixels in detector |
No |
CRp |
Scalar |
Electron/s |
Planet count rate |
No |
CRbs |
Scalar |
Electron/s |
Stellar leakage count rate |
No |
CRbz |
Scalar |
Electron/s |
Local zodiacal light count rate |
No |
CRbez |
Scalar |
Electron/s |
Exozodiacal light count rate |
No |
CRbbin |
Scalar |
Electron/s |
Binary star count rate |
No |
CRbth |
Scalar |
Electron/s |
Thermal background count rate |
No |
CRbd |
Scalar |
Electron/s |
Detector noise count rate |
No |
CRnf |
Scalar |
Electron/s |
Noise floor count rate |
No |
CRb |
Scalar |
Electron/s |
Total background count rate |
No |
t_photon_count |
Scalar |
s |
Photon counting time |
No |