def test_era_inverse(self):
# Check a full forward/inverse cycle
dt = datetime(2016, 4, 3, 2, 1, 0)
t1 = ctime.datetime_to_unix(dt)
era = ctime.unix_to_era(t1)
t2 = ctime.era_to_unix(era, t1 - 3600.0)
# Should be accurate at the 1 ms level
self.assertAlmostEqual(t1, t2, 3)
# Check a full forward/inverse cycle over a leap second boundary
dt = datetime(2009, 1, 1, 3, 0, 0)
t1 = ctime.datetime_to_unix(dt)
era = ctime.unix_to_era(t1)
t2 = ctime.era_to_unix(era, t1 - 6 * 3600.0)
# Should be accurate at the 10 ms level
self.assertAlmostEqual(t1, t2, 2)
def test_era_inverse(self):
# Check a full forward/inverse cycle
dt = datetime(2016, 4, 3, 2, 1, 0)
t1 = ctime.datetime_to_unix(dt)
era = ctime.unix_to_era(t1)
t2 = ctime.era_to_unix(era, t1 - 3600.0)
# Should be accurate at the 1 ms level
self.assertAlmostEqual(t1, t2, 3)
# Check a full forward/inverse cycle over a leap second boundary
dt = datetime(2009, 1, 1, 3, 0, 0)
t1 = ctime.datetime_to_unix(dt)
era = ctime.unix_to_era(t1)
t2 = ctime.era_to_unix(era, t1 - 6 * 3600.0)
# Should be accurate at the 10 ms level
self.assertAlmostEqual(t1, t2, 2)
def test_era_known(self):
# Check an ERA calculated by caput.time against one calculated by
# http://dc.zah.uni-heidelberg.de/apfs/times/q/form (note the latter
# uses UT1, so we have maximum precision of 1s)
dt = datetime(2016, 4, 3, 2, 1, 0)
t1 = ctime.datetime_to_unix(dt)
era1 = ctime.unix_to_era(t1)
era2 = 221.0 + (52.0 + 50.828 / 60.0) / 60.0
self.assertAlmostEqual(era1, era2, 3)
# Test another one
dt = datetime(2001, 2, 3, 4, 5, 6)
t1 = ctime.datetime_to_unix(dt)
era1 = ctime.unix_to_era(t1)
era2 = 194.0 + (40.0 + 11.549 / 60.0) / 60.0
self.assertAlmostEqual(era1, era2, 3)
def test_era_known(self):
# Check an ERA calculated by caput.time against one calculated by
# http://dc.zah.uni-heidelberg.de/apfs/times/q/form (note the latter
# uses UT1, so we have maximum precision of 1s)
dt = datetime(2016, 4, 3, 2, 1, 0)
t1 = ctime.datetime_to_unix(dt)
era1 = ctime.unix_to_era(t1)
era2 = 221.0 + (52.0 + 50.828 / 60.0) / 60.0
self.assertAlmostEqual(era1, era2, 3)
# Test another one
dt = datetime(2001, 2, 3, 4, 5, 6)
t1 = ctime.datetime_to_unix(dt)
era1 = ctime.unix_to_era(t1)
era2 = 194.0 + (40.0 + 11.549 / 60.0) / 60.0
self.assertAlmostEqual(era1, era2, 3)
def sun_coord(unix_time, deg=True):
date = ephemeris.ensure_unix(np.atleast_1d(unix_time))
skyfield_time = ephemeris.unix_to_skyfield_time(date)
ntime = date.size
coord = np.zeros((ntime, 4), dtype=np.float32)
planets = skyfield.api.load('de421.bsp')
sun = planets['sun']
observer = ephemeris._get_chime().skyfield_obs()
apparent = observer.at(skyfield_time).observe(sun).apparent()
radec = apparent.radec(epoch=skyfield_time)
coord[:, 0] = radec[0].radians
coord[:, 1] = radec[1].radians
altaz = apparent.altaz()
coord[:, 2] = altaz[0].radians
coord[:, 3] = altaz[1].radians
# Correct RA from equinox to CIRS coords using
# the equation of the origins
era = np.radians(ctime.unix_to_era(date))
gast = 2 * np.pi * skyfield_time.gast / 24.0
coord[:, 0] = coord[:, 0] + (era - gast)
# Convert to hour angle
coord[:, 0] = _correct_phase_wrap(coord[:, 0] -
np.radians(ephemeris.lsa(date)))
if deg:
coord = np.degrees(coord)
return coord
def parse_ant_logs(cls, logs, return_post_report_params=False):
"""
Unzip and parse .ANT log file output by nsched for John Galt Telescope
observations
Parameters
----------
logs : list of strings
.ZIP filenames. Each .ZIP archive should include a .ANT file and
a .POST_REPORT file. This method unzips the archive, uses
`parse_post_report` to read the .POST_REPORT file and extract
the CHIME sidereal day corresponding to the DRAO sidereal day,
and then reads the lines in the .ANT file to obtain the pointing
history of the Galt Telescope during this observation.
(The DRAO sidereal day is days since the clock in Ev Sheehan's
office at DRAO was reset. This clock is typically only reset every
few years, but it does not correspond to any defined date, so the
date must be figured out from the .POST_REPORT file, which reports
both the DRAO sidereal day and the UTC date and time.
Known reset dates: 2017-11-21, 2019-3-10)
Returns
-------
if output_params == False:
ant_data: A dictionary consisting of lists containing the LST,
hour angle, RA, and dec (all as Skyfield Angle objects),
CHIME sidereal day, and DRAO sidereal day.
if output_params == True
output_params: dictionary returned by `parse_post_report`
and
ant_data: described above
Files
-----
the .ANT and .POST_REPORT files in the input .zip archive are
extracted into /tmp/26mlog/<loginname>/
"""
from skyfield.positionlib import Angle
from caput import time as ctime
DRAO_lon = ephemeris.CHIMELONGITUDE * 24.0 / 360.0
def sidlst_to_csd(sid, lst, sid_ref, t_ref):
"""
Convert an integer DRAO sidereal day and LST to a float
CHIME sidereal day
Parameters
----------
sid : int
DRAO sidereal day
lst : float, in hours
local sidereal time
sid_ref : int
DRAO sidereal day at the reference time t_ref
t_ref : skyfield time object, Julian days
Reference time
Returns
-------
output : float
CHIME sidereal day
"""
csd_ref = int(
ephemeris.csd(ephemeris.datetime_to_unix(
t_ref.utc_datetime())))
csd = sid - sid_ref + csd_ref
return csd + lst / ephemeris.SIDEREAL_S / 24.0
ant_data_list = []
post_report_list = []
for log in logs:
doobs = True
filename = log.split("/")[-1]
basedir = "/tmp/26mlog/{}/".format(os.getlogin())
basename, extension = filename.split(".")
post_report_file = basename + ".POST_REPORT"
ant_file = basename + ".ANT"
if extension == "zip":
try:
zipfile.ZipFile(log).extract(post_report_file,
path=basedir)
except:
print(
"Failed to extract {} into {}. Moving right along...".
format(post_report_file, basedir))
doobs = False
try:
zipfile.ZipFile(log).extract(ant_file, path=basedir)
except:
print(
"Failed to extract {} into {}. Moving right along...".
format(ant_file, basedir))
doobs = False
if doobs:
try:
post_report_params = cls.parse_post_report(
basedir + post_report_file)
with open(os.path.join(basedir, ant_file), "r") as f:
lines = [line for line in f]
ant_data = {"sid": np.array([])}
lsth = []
lstm = []
lsts = []
hah = []
ham = []
has = []
decd = []
decm = []
decs = []
for l in lines:
arr = l.split()
try:
lst_hms = [float(x) for x in arr[2].split(":")]
# do last element first: if this is going to
# crash because a line in the log is incomplete,
# we don't want it to append to any of the lists
decs.append(float(arr[8].replace('"', "")))
decm.append(float(arr[7].replace("'", "")))
decd.append(float(arr[6].replace("D", "")))
has.append(float(arr[5].replace("S", "")))
ham.append(float(arr[4].replace("M", "")))
hah.append(float(arr[3].replace("H", "")))
lsts.append(float(lst_hms[2]))
lstm.append(float(lst_hms[1]))
lsth.append(float(lst_hms[0]))
ant_data["sid"] = np.append(
ant_data["sid"], int(arr[1]))
except:
print("Failed in file {} for line \n{}".format(
ant_file, l))
if len(ant_data["sid"]) != len(decs):
print("WARNING: mismatch in list lengths.")
ant_data["lst"] = Angle(hours=(lsth, lstm, lsts))
ha = Angle(hours=(hah, ham, has))
dec = Angle(degrees=(decd, decm, decs))
ant_data["ha"] = Angle(
radians=ha.radians -
ephemeris.galt_pointing_model_ha(ha, dec).radians,
preference="hours",
)
ant_data["dec_cirs"] = Angle(
radians=dec.radians -
ephemeris.galt_pointing_model_dec(ha, dec).radians,
preference="degrees",
)
ant_data["csd"] = sidlst_to_csd(
np.array(ant_data["sid"]),
ant_data["lst"].hours,
post_report_params["SID"],
post_report_params["start_time"],
)
ant_data["t"] = ephemeris.unix_to_skyfield_time(
ephemeris.csd_to_unix(ant_data["csd"]))
# Correct RA from equinox to CIRS coords (both in radians)
era = np.radians(
ctime.unix_to_era(ephemeris.ensure_unix(
ant_data["t"])))
gast = ant_data["t"].gast * 2 * np.pi / 24.0
ant_data["ra_cirs"] = Angle(
radians=ant_data["lst"].radians -
ant_data["ha"].radians + (era - gast),
preference="hours",
)
obs = ephemeris.Star_cirs(
ra=ant_data["ra_cirs"],
dec=ant_data["dec_cirs"],
epoch=ant_data["t"],
)
ant_data["ra"] = obs.ra
ant_data["dec"] = obs.dec
ant_data_list.append(ant_data)
post_report_list.append(post_report_params)
except:
print("Parsing {} failed".format(post_report_file))
if return_post_report_params:
return post_report_list, ant_data_list
return ant_data