def test_sky_position(t1, t2):
pos1 = sun.sky_position(t1)
ra1 = sun.apparent_rightascension(t1)
dec1 = sun.apparent_declination(t1)
assert_quantity_allclose(pos1, (ra1, dec1))
pos2 = sun.sky_position(t2, equinox_of_date=False)
ra2 = sun.apparent_rightascension(t2, equinox_of_date=False)
dec2 = sun.apparent_declination(t2, equinox_of_date=False)
assert_quantity_allclose(pos2, (ra2, dec2))
def test_apparent_declination(t1, t2):
# Validate against a published value from the Astronomical Almanac (1992, C16)
assert_quantity_allclose(sun.apparent_declination(t1),
Angle('-7d47m01.7s'),
atol=0.05 * u.arcsec)
# Validate against a published value from the Astronomical Almanac (2013, C12)
assert_quantity_allclose(sun.apparent_declination(t2),
Angle('23d22m27.8s'),
atol=0.05 * u.arcsec)
def get_detector_sun_angles_for_date(date, file):
"""
get the GBM detector angles vs the sun as a function of time for a given
date
Parameters
----------
date : `astropy.time.Time`
A `~astropy.time.Time` object or other date format understood by the parse_time
function.
file : `str`
A filepath to a Fermi/LAT weekly pointing file (e.g. as obtained by the
download_weekly_pointing_file function).
"""
date = parse_time(date)
tran = TimeRange(date, date + TimeDelta(1 * u.day))
scx, scz, times = get_scx_scz_in_timerange(tran, file)
# retrieve the detector angle information in spacecraft coordinates
detectors = nai_detector_angles()
detector_to_sun_angles = []
# get the detector vs Sun angles for each t and store in a list of
# dictionaries.
for i in range(len(scx)):
detector_radecs = nai_detector_radecs(detectors, scx[i], scz[i],
times[i])
# this gets the sun position with RA in hours in decimal format
# (e.g. 4.3). DEC is already in degrees
sunpos_ra_not_in_deg = [
sun.apparent_rightascension(times[i]),
sun.apparent_declination(times[i])
]
# now Sun position with RA in degrees
sun_pos = [sunpos_ra_not_in_deg[0].to('deg'), sunpos_ra_not_in_deg[1]]
# now get the angle between each detector and the Sun
detector_to_sun_angles.append(
get_detector_separation_angles(detector_radecs, sun_pos))
# slice the list of dictionaries to get the angles for each detector in a
# list form
angles = OrderedDict()
key_list = [
'n0', 'n1', 'n2', 'n3', 'n4', 'n5', 'n6', 'n7', 'n8', 'n9', 'n10',
'n11', 'time'
]
for i in range(13):
if not key_list[i] == 'time':
angles[key_list[i]] = [
item[key_list[i]].value for item in detector_to_sun_angles
] * u.deg
else:
angles[key_list[i]] = [
item[key_list[i]] for item in detector_to_sun_angles
]
return angles
def get_detector_sun_angles_for_time(time, file):
"""
Get the GBM detector angles vs the Sun for a single time.
Parameters
----------
time : {parse_time_types}
A time specified as a parse_time-compatible
time string, number, or a datetime object.
file : `str`
A filepath to a Fermi/LAT weekly pointing file (e.g. as obtained by the
download_weekly_pointing_file function).
Returns
-------
`tuple`:
A tuple of all the detector angles.
"""
time = parse_time(time)
scx, scz, tt = get_scx_scz_at_time(time, file)
# retrieve the detector angle information in spacecraft coordinates
detectors = nai_detector_angles()
# get the detector pointings in RA/DEC given the input spacecraft x and z
# axes
detector_radecs = nai_detector_radecs(detectors, scx, scz, tt)
# this gets the sun position with RA in hours in decimal format (e.g. 4.3).
# DEC is already in degrees
sunpos_ra_not_in_deg = [
sun.apparent_rightascension(time),
sun.apparent_declination(time)
]
# now Sun position with RA in degrees
sun_pos = [sunpos_ra_not_in_deg[0].to('deg'), sunpos_ra_not_in_deg[1]]
# sun_pos = [(sunpos_ra_not_in_deg[0] / 24) * 360., sunpos_ra_not_in_deg[1]]
# now get the angle between each detector and the Sun
detector_to_sun_angles = (get_detector_separation_angles(
detector_radecs, sun_pos))
return detector_to_sun_angles
def test_apparent_declination_J2000(t1):
# Regression-only test
assert_quantity_allclose(sun.apparent_declination(t1,
equinox_of_date=False),
Angle('-7d49m13.1s'),
atol=0.05 * u.arcsec)
def get_detector_sun_angles_for_date(date, file):
"""
Get the GBM detector angles vs the Sun as a function of time for a given
date.
Parameters
----------
date : {parse_time_types}
A date specified as a parse_time-compatible
time string, number, or a datetime object.
file : `str`
A filepath to a Fermi/LAT weekly pointing file (e.g. as obtained by the
download_weekly_pointing_file function).
Returns
-------
`tuple`:
A tuple of all the detector angles.
"""
date = parse_time(date)
tran = TimeRange(date, date + TimeDelta(1 * u.day))
scx, scz, times = get_scx_scz_in_timerange(tran, file)
# retrieve the detector angle information in spacecraft coordinates
detectors = nai_detector_angles()
detector_to_sun_angles = []
# get the detector vs Sun angles for each t and store in a list of
# dictionaries.
for i in range(len(scx)):
detector_radecs = nai_detector_radecs(detectors, scx[i], scz[i],
times[i])
# this gets the sun position with RA in hours in decimal format
# (e.g. 4.3). DEC is already in degrees
sunpos_ra_not_in_deg = [
sun.apparent_rightascension(times[i]),
sun.apparent_declination(times[i]),
]
# now Sun position with RA in degrees
sun_pos = [sunpos_ra_not_in_deg[0].to("deg"), sunpos_ra_not_in_deg[1]]
# now get the angle between each detector and the Sun
detector_to_sun_angles.append(
get_detector_separation_angles(detector_radecs, sun_pos))
# slice the list of dictionaries to get the angles for each detector in a
# list form
angles = OrderedDict()
key_list = [
"n0",
"n1",
"n2",
"n3",
"n4",
"n5",
"n6",
"n7",
"n8",
"n9",
"n10",
"n11",
"time",
]
for i in range(13):
if not key_list[i] == "time":
angles[key_list[i]] = [
item[key_list[i]].value for item in detector_to_sun_angles
] * u.deg
else:
angles[key_list[i]] = [
item[key_list[i]] for item in detector_to_sun_angles
]
return angles
