"""Provisional DES instrument and observational settings.
See Optics and Observation Conditions spreadsheet at
https://docs.google.com/spreadsheets/d/1pMUB_OOZWwXON2dd5oP8PekhCT5MBBZJO1HV7IMZg4Y/edit?usp=sharing
for list of
sources.
"""
import lenstronomy.Util.util as util
__all__ = ["DES"]
g_band_obs = {
"exposure_time": 90.0,
"sky_brightness": 22.01,
"magnitude_zero_point": 26.58,
"num_exposures": 10,
"seeing": 1.12,
"psf_type": "GAUSSIAN",
}
r_band_obs = {
"exposure_time": 90.0,
"sky_brightness": 21.15,
"magnitude_zero_point": 26.78,
"num_exposures": 10,
"seeing": 0.96,
"psf_type": "GAUSSIAN",
}
i_band_obs = {
"exposure_time": 90.0,
"sky_brightness": 19.89,
"magnitude_zero_point": 26.75,
"num_exposures": 10,
"seeing": 0.88,
"psf_type": "GAUSSIAN",
}
z_band_obs = {
"exposure_time": 90.0,
"sky_brightness": 18.72,
"magnitude_zero_point": 26.48,
"num_exposures": 10,
"seeing": 0.84,
"psf_type": "GAUSSIAN",
}
Y_band_obs = {
"exposure_time": 45.0,
"sky_brightness": 17.96,
"magnitude_zero_point": 25.40,
"num_exposures": 10,
"seeing": 0.9,
"psf_type": "GAUSSIAN",
}
# - keyword exposure_time: exposure time per image (in seconds)
# - keyword sky_brightness: sky brightness (in magnitude per square arcseconds in units of electrons)
# - keyword magnitude_zero_point: magnitude in which 1 count (e-) per second per arcsecond square is registered
# - keyword num_exposures: number of exposures that are combined (depends on coadd_years)
# - keyword seeing: Full-Width-at-Half-Maximum (FWHM) of PSF
# - keyword psf_type: string, type of PSF ('GAUSSIAN' supported)
[docs]
class DES(object):
"""Class contains DES instrument and observation configurations."""
[docs]
def __init__(self, band="g", psf_type="GAUSSIAN", coadd_years=3):
"""
:param band: string, 'g', 'r', 'i', 'z', or 'Y' supported. Determines obs dictionary.
:param psf_type: string, type of PSF ('GAUSSIAN' supported).
:param coadd_years: int, number of years corresponding to num_exposures in obs dict. Currently supported: 1-6.
"""
if band == "g":
self.obs = g_band_obs
elif band == "r":
self.obs = r_band_obs
elif band == "i":
self.obs = i_band_obs
elif band == "z":
self.obs = z_band_obs
elif band == "Y":
self.obs = Y_band_obs
else:
raise ValueError(
"band %s not supported! Choose 'g', 'r', 'i', 'z', or 'Y'." % band
)
if psf_type != "GAUSSIAN":
raise ValueError("psf_type %s not supported!" % psf_type)
if coadd_years > 6 or coadd_years < 1:
raise ValueError(
" %s coadd_years not supported! Choose an integer between 1 and 6."
% coadd_years
)
elif coadd_years != 3:
self.obs["num_exposures"] = (coadd_years * 10) // 3
self.camera = {"read_noise": 7, "pixel_scale": 0.263, "ccd_gain": 4}
# - keyword read_noise: std of noise generated by read-out (in units of electrons)
# - keyword pixel_scale: scale (in arcseconds) of pixels
# - keyword ccd_gain: electrons/ADU (analog-to-digital unit)
[docs]
def kwargs_single_band(self):
"""
:return: merged kwargs from camera and obs dicts
"""
kwargs = util.merge_dicts(self.camera, self.obs)
return kwargs