def ignore_epochs(dset):
"""Edits data based on data quality
Args:
dset: A Dataset containing model data.
Returns:
Array containing False for observations to throw away
"""
intervals = config.tech[_SECTION].intervals.as_list(split_re=", *")
keep_idx = np.ones(dset.num_obs, dtype=bool)
for interval in intervals:
interval = interval.split()
start_time = Time(" ".join(interval[-4:-2]), scale="utc", fmt="iso")
end_time = Time(" ".join(interval[-2:]), scale="utc", fmt="iso")
# station name may contain spaces
station = " ".join(interval[:-4])
remove_idx = np.logical_and(start_time < dset.time,
dset.time < end_time)
if len(interval) == 5:
if "/" in station:
remove_idx = dset.filter(baseline=station, idx=remove_idx)
else:
remove_idx = dset.filter(station=station, idx=remove_idx)
keep_idx = np.logical_and(keep_idx, np.logical_not(remove_idx))
return keep_idx
def _calculate_pos_trs(self, site):
"""Calculate positions for the given time epochs
The positions are calculated as simple linear offsets based on the reference epoch. Makes sure to pick out the
correct time interval to use.
Args:
key: Key saying which site to calculate position for, type might depend on the Trf.
Returns:
Array: Positions, one 3-vector for each time epoch.
"""
station_info = self.data[site]
ref_epoch = Time(float(station_info["ref_epoch"]),
fmt="decimalyear",
scale="utc")
pos = np.full((self.time.size, 3), fill_value=np.nan)
ref_pos = np.array(station_info["pos"])
ref_vel = np.array(station_info["vel"])
interval_years = (self.time - ref_epoch).jd * Unit.day2julian_years
pos[:, :] = ref_pos + interval_years[:, None] * ref_vel[None, :]
ell = ellipsoid.get("GRS80")
pos_trs = Position(pos, system="trs", ellipsoid=ell, time=self.time)
return np.squeeze(pos_trs)
def _calculate_pos_trs(self, site):
"""Calculate positions for the given time epochs
The positions are calculated as simple linear offsets based on the reference epoch.
Args:
site (String): Key saying which site to calculate position for.
Returns:
Array: Positions, one 3-vector for each time epoch.
"""
station_info = self.data[site]
ref_epoch = Time(station_info["ref_epoch"], scale="utc", fmt="datetime")
pos = np.zeros((self.time.size, 3))
for pv in station_info["pos_vel"].values():
idx = np.logical_and(self.time.utc.datetime >= pv["start"], self.time.utc.datetime < pv["end"])
if idx.size == 1:
idx = np.array([idx])
if not any(idx):
continue
ref_pos = np.array([pv["STAX"], pv["STAY"], pv["STAZ"]])
ref_vel = np.array([pv["VELX"], pv["VELY"], pv["VELZ"]])
interval_years = (self.time - ref_epoch).jd * Unit.day2julian_years
if isinstance(interval_years, float):
interval_years = np.array([interval_years])
pos[idx, :] = ref_pos + interval_years[idx, None] * ref_vel[None, :]
ell = ellipsoid.get(config.tech.reference_ellipsoid.str.upper())
pos_trs = Position(pos, system="trs", ellipsoid=ell, time=self.time)
return np.squeeze(pos_trs)
def _check_last_epoch_sample_point(dset, precise, epoch_interval):
"""Keep last observation epoch depending on existing precise orbit sample points
Precise orbit sample points are needed to carry out interpolation of precise orbits for the last observation
epochs. If no precise orbit sample point is available after the last satellite observation epochs, then this
epochs will be removed for this satellite.
The time difference between the last observation epochs and the next precise orbit sample point is determined. 'Last
observation epoch' + 'sampling rate' is chosen as reference time for the selection of the nearest orbit sample
point, which corresponds normally to 0:00 GPS time. If the time difference exceeds the following intervall, then the
observation epochs are rejected:
-(precise orbit epoch interval + 1) < time difference < 0
Args:
dset (Dataset): A Dataset containing model data.
dset_idx (numpy.ndarray): Array containing False for observations to throw away. The array is returned by
function `ignore_unavailable_orbit_satellites()`, which deletes unavailable
apriori orbit satellites.
precise (PreciseOrbit): Precise orbit object with precise orbit information.
epoch_interval (float): Epoch interval of precise orbit sample points
Returns:
tuple: Tuple with array containing False for last observations to throw away and indices indicating last
observation epoch.
"""
sampling_rate = config.tech.sampling_rate.float
# Get indices for last observation epochs
last_idx = -1
last_epoch_idx = np.ones(dset.num_obs, dtype=bool)
last_epoch_idx = (dset.time.gps.mjd >= dset.time.gps.mjd[last_idx] -
(epoch_interval - sampling_rate) * Unit.second2day)
# Get set with satellite and time entries for getting corresponding precise orbit sample points
# Note: Sample point reference time is 'last observation epoch' + 'sampling rate', which corresponds normally to
# 0:00 GPS time.
satellites = dset.satellite[last_epoch_idx]
time = Time(val=dset.time.gps.datetime[last_idx],
fmt="datetime",
scale=dset.time.scale) + TimeDelta(
sampling_rate, fmt="seconds", scale=dset.time.scale)
precise_idx = precise._get_nearest_sample_point(satellites, time)
# Keep observations epochs, where a precise orbit sample point exists after the last observation epoch
diff_time = (dset.time.gps.mjd[last_epoch_idx] -
precise.dset_edit.time.gps.mjd[precise_idx]) * Unit.day2second
keep_idx = np.logical_and(diff_time > -(epoch_interval + 1), diff_time < 0)
removed_entries = "DEBUG: ".join([
f"{s} {t.strftime(' %Y-%m-%d %H:%M:%S (GPS)')}, dt = {dt:8.2f} s ({-(epoch_interval + 1)} < dt < 0)\n"
for s, t, dt in zip(
satellites[np.logical_not(keep_idx)],
dset.time.gps.datetime[last_epoch_idx][np.logical_not(keep_idx)],
diff_time[np.logical_not(keep_idx)],
)
])
log.debug(f"Following last epoch entries are removed: \n{removed_entries}")
return keep_idx, last_epoch_idx
def date_vars(date):
"""Construct a dict of date variables
From a given date, construct a dict containing all relevant date variables. This dict can be used to for instance
replace variables in file names.
Examples:
>>> from datetime import date
>>> date_vars = date_vars(date(2009, 11, 2))
>>> sorted(date_vars.items()) # doctest: +NORMALIZE_WHITESPACE
[('MMM', 'NOV'), ('ce', '20'), ('d', '2'), ('dd', '02'), ('dow', '1'), ('doy', '306'), ('gpsweek', '1556'),
('m', '11'), ('mm', '11'), ('mmm', 'nov'), ('yy', '09'), ('yyyy', '2009')]
Args:
date (Date/Datetime): The date.
Returns:
Dict: Dictionary with date variables for the given date.
"""
if date is None:
return dict()
# Import Time locally to avoid circular imports
from where.data.time import Time
month = [
"jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct",
"nov", "dec"
]
# Create the dict of date variables
try:
gpsweek = str(
int(
Time(date.strftime("%Y-%m-%d %H:%M:%S"),
fmt="iso",
scale="utc").gps.gps_ws.week))
except ValueError:
# gps-scale is not defined for 1970-01-01, which is used by timeseries
gpsweek = ""
return dict(
date=date.strftime("%Y%m%d"),
yyyy=date.strftime("%Y"),
ce=date.strftime("%Y")[:2],
yy=date.strftime("%y"),
m=str(date.month),
mm=date.strftime("%m"),
mmm=month[date.month - 1].lower(),
MMM=month[date.month - 1].upper(),
d=str(date.day),
dd=date.strftime("%d"),
hh=date.strftime("%H"),
doy=date.strftime("%j"),
dow=date.strftime("%w"),
gpsweek=gpsweek,
)
def remove_low_frequency_tides(self):
"""Remove the effect of low frequency tides.
Tidal variations in the Earth's rotation with periods from 5 days to 18.6 years is present in the UT1-UTC time
series as described in the IERS Conventions 2010 chapter 8.1. To improve the interpolation of the UT1-UTC time
series this effect can be removed. In that case the effect needs to be added again to the final interpolated
values.
"""
for mjd in self.data.keys():
t = Time(mjd, fmt="mjd", scale="utc")
self.data[mjd]["ut1_utc"] -= iers.rg_zont2(t)[0]
def calculate_leap_second_offset(self):
"""Calculate leap second offsets for each day
Use the difference between UTC and TAI as a proxy for the leap second offset. The leap second offset is
calculated and stored to the EOP data-dictionary. This is used to correct for the leap second jumps when
interpolating the UT1 - UTC values.
"""
days = Time(np.array(list(self.data.keys())), fmt="mjd", scale="utc")
leap_offset = np.round((days.utc.mjd - days.tai.mjd) * Unit.day2seconds)
daily_offset = {int(d): lo for d, lo in zip(days.mjd, leap_offset)}
for d, lo in daily_offset.items():
self.data[d]["leap_offset"] = lo
def _check_first_epoch_sample_point(dset: "Dataset", precise, epoch_interval):
"""Keep first observation epoch depending on existing precise orbit sample points
Precise orbit sample points are needed to carry out interpolation of precise orbits for the first observation
epoch. If no precise orbit sample point is available before the first satellite observation epoch, then this
epoch will be removed for this satellite.
Args:
dset (Dataset): A Dataset containing model data.
dset_idx (numpy.ndarray): Array containing False for observations to throw away. The array is returned by
function `ignore_unavailable_orbit_satellites()`, which deletes unavailable
apriori orbit satellites.
precise (PreciseOrbit): Precise orbit object with precise orbit information.
epoch_interval (float): Epoch interval of precise orbit sample points
Returns:
tuple: Tuple with array containing False for first observations to throw away and indices indicating first
observation epoch.
"""
# Get indices for first observation epochs
first_idx = 0
first_epoch_idx = np.ones(dset.num_obs, dtype=bool)
first_epoch_idx = dset.time.gps.mjd == dset.time.gps.mjd[first_idx]
# Get set with satellite and time entries for getting corresponding precise orbit sample points
satellites = dset.satellite[first_epoch_idx]
time = Time(val=dset.time.gps.datetime[first_epoch_idx],
fmt="datetime",
scale=dset.time.scale) - TimeDelta(
epoch_interval, fmt="seconds", scale=dset.time.scale)
precise_idx = precise._get_nearest_sample_point(satellites, time)
# Keep observations epochs, where a precise orbit sample point exists before the first observation epoch
diff_time = (dset.time.gps.mjd[first_epoch_idx] -
precise.dset_edit.time.gps.mjd[precise_idx]) * Unit.day2second
keep_idx = np.logical_and(diff_time < (epoch_interval + 1), diff_time > 0)
removed_entries = "DEBUG: ".join([
f"{s} {t.strftime(' %Y-%m-%d %H:%M:%S (GPS)')}, dt = {dt:8.2f} s (0 < dt < {epoch_interval + 1})\n"
for s, t, dt in zip(
satellites[np.logical_not(keep_idx)],
dset.time.gps.datetime[first_epoch_idx][np.logical_not(keep_idx)],
diff_time[np.logical_not(keep_idx)],
)
])
log.info(
f"Following first epoch entries are removed: \nDEBUG: {removed_entries}"
)
return keep_idx, first_epoch_idx
def parse_clock_breaks(dset, clock_breaks):
"""Parses the clock breaks string from the edit file
Examples:
> parse_clock_breaks(dset, '')
(OrderedDict(), 0)
> parse_clock_breaks(dset, 'SVETLOE 2015/01/23 05:36:00,
SVETLOE 2015/01/23 16:53:00,
SVETLOE 2015/01/23 12:30:00')
(OrderedDict([(5, [106560.0, 131400.0, 147180.0])]), 3)
Args:
dset: A Dataset containing model data.
clock_breaks_str: A string with clock break information
Returns:
OrderedDict with clock breaks and total number of clock breaks
"""
# Parse clock breaks from file and store in the station_breaks dictionary
station_breaks = {
s: [min(dset.time.utc), max(dset.time.utc) + TimeDelta(1, fmt="seconds", scale="utc")]
for s in dset.unique("station")
}
if clock_breaks:
log.info(f"Applying clock breaks: {', '.join(clock_breaks)}")
for cb in clock_breaks:
# Station names may contain spaces
cb = cb.split()
cb_date = cb[-2:]
cb_station = " ".join(cb[:-2])
# cb_station, *cb_date = cb.split()
cb_time = Time(" ".join(cb_date), scale="utc", fmt="iso")
if cb_station not in station_breaks:
log.warn(
f"Station {cb_station} with clock break unknown. Available options are {', '.join(station_breaks)}"
)
continue
station_breaks[cb_station].append(cb_time)
dset.meta.add_event(cb_time, "clock_break", cb_station)
# Convert the station_breaks dict to lists of (station, (time_start, time_end))-tuples
stations = list()
time_intervals = list()
for station in sorted(station_breaks.keys(), key=lambda s: (len(station_breaks[s]), s), reverse=True):
station_times = sorted(station_breaks[station])
for t_start, t_end in zip(station_times[:-1], station_times[1:]):
stations.append(station)
time_intervals.append((t_start, t_end))
return stations, time_intervals
def parse_clock_breaks(dset):
"""Parses the clock breaks string from the edit file
Args:
dset: A Dataset containing model data.
clock_breaks_str: A string with clock break information
Returns:
OrderedDict with clock breaks and total number of clock breaks
"""
station_breaks = {
s: [min(dset.time.utc), max(dset.time.utc) + TimeDelta(1, fmt="seconds", scale="utc")]
for s in dset.unique("station")
}
clock_breaks = config.tech.get("clock_breaks", section=MODEL).as_list(split_re=", *")
if clock_breaks:
log.info(f"Applying clock breaks: {', '.join(clock_breaks)}")
for cb in clock_breaks:
# Station names may contain spaces
cb = cb.split()
cb_date = cb[-2:]
cb_station = " ".join(cb[:-2])
cb_time = Time(" ".join(cb_date), scale="utc", fmt="iso")
if cb_station not in station_breaks:
log.warn(
f"Station {cb_station} with clock break unknown. Available options are {', '.join(station_breaks)}"
)
continue
station_breaks[cb_station].append(cb_time)
dset.meta.add_event(cb_time, "clock_break", cb_station)
# Convert the station_breaks dict to lists of (station, (time_start, time_end))-tuples
stations = list()
time_intervals = list()
for station in sorted(station_breaks.keys(), key=lambda s: (len(station_breaks[s]), s), reverse=True):
station_times = sorted(station_breaks[station])
for t_start, t_end in zip(station_times[:-1], station_times[1:]):
stations.append(station)
time_intervals.append((t_start, t_end))
return stations, time_intervals
def ignore_observation(dset):
"""Removes given observations
Args:
dset: A Dataset containing model data.
Returns:
Array containing False for observations to throw away
"""
observations = config.tech[_SECTION].observations.as_list(split_re=", *")
keep_idx = np.ones(dset.num_obs, dtype=bool)
for observation in observations:
date, time, *stations = observation.split()
epoch = Time(f"{date} {time}", scale="utc", fmt="iso")
stations = (" ".join(stations)).split(
"/") # station names may contain spaces, split at slash instead
remove_idx = dset.time.utc.iso == epoch.utc.iso
for station in stations:
remove_idx = dset.filter(station=station, idx=remove_idx)
keep_idx[remove_idx] = False
return keep_idx
def detect_clockbreaks(dset):
"""Try to detect a clock break
The suspected clock breaks are added to the dataset as events. They will not be corrected automatically.
TODO: Clean up code / better variable names, remove "magic" numbers, possibly put settings in config?
Handle gaps in observations better, these are often misinterpreted as clock breaks
These might be made faster by using a filter to test all observations at the same time?
Args:
dset (Dataset): Information about model run.
"""
log.info("Looking for clock breaks")
clock_breaks = list()
order_of_polynomial = config.tech.get("order_of_polynomial", section="vlbi_clock_poly", default=2).int
for station in dset.unique("station"):
# Merge together data where station is station 1 and station 2
idx_1 = dset.filter(station_1=station)
idx_2 = dset.filter(station_2=station)
time = np.hstack((dset.time.utc.mjd[idx_1], dset.time.utc.mjd[idx_2])) - dset.time.utc.mjd[0]
residual = np.hstack((dset.residual[idx_1], -dset.residual[idx_2]))
# Make sure data are chronological
idx_sort = np.argsort(time)
time = time[idx_sort]
residual = residual[idx_sort]
# Add fields to dset for debug
idx_site = np.hstack((np.where(idx_1)[0], np.where(idx_2)[0]))[idx_sort]
dset.add_float(f"cb_{station}_residual", np.zeros(dset.num_obs), write_level="operational")
dset[f"cb_{station}_residual"][idx_site] = residual
dset.add_float(f"cb_{station}_value", np.zeros(dset.num_obs), write_level="detail")
dset.add_float(f"cb_{station}_limit", np.zeros(dset.num_obs), write_level="detail")
dset.add_float(f"cb_{station}_pred", np.zeros(dset.num_obs), write_level="detail")
dset.add_float(f"cb_{station}_ratio", np.zeros(dset.num_obs), write_level="detail")
# Test each observation for clock break
start_obs = 0
for obs in range(len(time) - 25):
if obs - start_obs < 25: # Need some observations to do polyfit
continue
# Fit a polynomial to the given data
idx_fit = slice(np.maximum(start_obs, obs - 500), obs) # Possibly better to limit on time instead of obs?
p = np.polyfit(time[idx_fit], residual[idx_fit], order_of_polynomial) # Same degree as clock correction
poly = np.polyval(p, time[idx_fit])
res = residual[idx_fit] - poly
std_lim = 2 * np.std(res) * (1 + 4 * np.exp(-10 * ((obs - np.maximum(start_obs, obs - 500)) / 500) ** 2))
# Gives higher limit when there are fewer observations in res
# Test next observations
model = np.polyval(
p, time[obs + 1 : obs + 26]
) # Use many (=25) observations to avoid problems with outliers
obs_res = residual[obs + 1 : obs + 26]
dset[f"cb_{station}_value"][idx_site[obs]] = np.min(np.abs(obs_res - model))
dset[f"cb_{station}_limit"][idx_site[obs]] = std_lim
dset[f"cb_{station}_pred"][idx_site[obs]] = model[0]
dset[f"cb_{station}_ratio"][idx_site[obs]] = np.min(np.abs(obs_res - model)) / std_lim
# Register possible clock break
if np.all(np.abs(obs_res - model) > std_lim):
start_obs = np.min(np.where(time > time[obs])[0]) # Next epoch with observations
time_cb = Time(dset.time.utc.mjd[0] + (time[obs] + time[start_obs]) / 2, fmt="mjd", scale="utc")
clock_breaks.append((np.min(np.abs(obs_res - model)) / std_lim, time_cb, station))
# Only actually add the biggest clock breaks, because big clock breaks creates smaller false clock breaks
ratio_lim = max(cb[0] for cb in clock_breaks) / 3 if clock_breaks else 1
for ratio, time, station in clock_breaks:
if ratio > ratio_lim:
dset.meta.add_event(time, "suspected_clock_break", station)
cb_time = time.datetime.strftime(config.FMT_datetime)
stars = "*" * int(np.ceil(np.log2(ratio)))
log.check(f"Found possible clock break for {station} at {cb_time} ({stars})")
def setUp(self):
# TODO: Configuration has to be defined? How? where.set_config(2016, 3, 1, 'gps')?
time = Time(2457448.5, fmt="jd", scale="tdb") # Julian Day in TDB time scale
self.eph = apriori.get("ephemerides", time=time, ephemerides="de430")
def setUp(self):
"""
The first test set up is based on the bc_velo.c program, which is published in :cite:`remondi2004` and
following RINEX navigation file sample:
/* Sample Broadcast Message in unit of radians, seconds, meters.
20 01 7 23 2 0 0.0 -.857324339449D-04 -.272848410532D-11 .000000000000D+00
.200000000000D+02 .886875000000D+02 .465376527657D-08 .105827953357D+01
.457651913166D-05 .223578442819D-02 .177137553692D-05 .515379589081D+04
.936000000000D+05 .651925802231D-07 .164046615454D+01 -.856816768646D-07
.961685061380D+00 .344968750000D+03 .206374037770D+01 -.856928551657D-08
.342514267094D-09 .000000000000D+00 .112400000000D+04 .000000000000D+00
.200000000000D+01 .000000000000D+00 -.651925802231D-08 .276000000000D+03
.865800000000D+05 .000000000000D+00 .000000000000D+00 .000000000000D+00
*/
The second test set up compares results from Where against gLAB solution for satellite G20 and epoch
2016-03-01 00:00:00.0.
/* Sample Broadcast Message in unit of radians, seconds, meters for satellite G20 and
/ epoch 2016-03-01 00:00:00.0
20 16 3 1 0 0 0.0 0.396233052015D-03 0.261479726760D-11 0.000000000000D+00
0.100000000000D+02-0.231562500000D+02 0.530236372187D-08 0.253477496869D+00
-0.111199915409D-05 0.483385741245D-02 0.810064375401D-05 0.515369705963D+04
0.172800000000D+06-0.141561031342D-06 0.304306271006D+00 0.372529029846D-08
0.926615731710D+00 0.207250000000D+03 0.133849764271D+01-0.843427989304D-08
-0.164292557730D-09 0.100000000000D+01 0.188600000000D+04 0.000000000000D+00
0.200000000000D+01 0.000000000000D+00-0.838190317154D-08 0.100000000000D+02
0.172770000000D+06 0.400000000000D+01 0.000000000000D+00 0.000000000000D+00
The second test set up compares results from Where against gLAB solution for satellite E11 and epoch
2016-03-01 00:00:00.0.
/* Sample Broadcast Message in unit of radians, seconds, meters for satellite E11 and
/ epoch 2016-03-01 00:00:00.0
E11 2016 03 01 00 00 00 6.643886445090e-05 1.097077984014e-11 0.000000000000e+00
3.200000000000e+01-3.243750000000e+01 3.015839907552e-09 2.397505637802e+00
-1.462176442146e-06 3.306962316856e-04 8.240342140198e-06 5.440621692657e+03
1.728000000000e+05 9.313225746155e-09-1.259905024101e+00 5.960464477539e-08
9.679475503522e-01 1.663125000000e+02-6.590241211713e-01-5.572732126661e-09
2.775115594704e-10 2.580000000000e+02 1.886000000000e+03
3.120000000000e+00 0.000000000000e+00-2.328306436539e-08 0.000000000000e+00
1.735000000000e+05
"""
# Get GNSS ephemeris data for testing
if TEST == "test_1":
file_key = "test_apriori_orbit_broadcast_1"
year = 2001
month = 7
day = 23
hour = 2
minute = 0
second = 0.0
satellite = "G20"
self.system = "G" # GNSS identifier
# Satellite transmission time
self.t_sat = 86400.00
elif TEST == "test_2":
file_key = "test_apriori_orbit_broadcast_2"
year = 2016
month = 3
day = 1
hour = 0
minute = 0
second = 0.0
satellite = "G20"
self.system = "G" # GNSS identifier
# Satellite transmission time
self.t_sat = 172799.92312317
elif TEST == "test_3":
file_key = "test_apriori_orbit_broadcast_3"
year = 2016
month = 3
day = 1
hour = 0
minute = 0
second = 0.0
satellite = "E11"
self.system = "E" # GNSS identifier
# Satellite transmission time
self.t_sat = 173699.999
rundate = datetime(year, month, day, hour, minute)
time = Time(
[("{year}-{month:02d}-{day:02d}T{hour:02d}:{minute:02d}:{second:010.7f}"
"".format(year=year,
month=month,
day=day,
hour=hour,
minute=minute,
second=second))],
fmt="isot",
scale="gps",
)
self.brdc = apriori.get(
"orbit",
apriori_orbit="broadcast",
rundate=rundate,
time=time,
satellite=tuple({satellite}),
system=tuple({self.system}),
station="test",
file_key=file_key,
)
self.idx = 0 # Broadcast ephemeris index
def _calculate_pos_trs(self, site):
"""Calculate positions for the given time epochs
The positions are calculated as simple linear offsets based on the reference epoch. If there is a post-seismic
deformations model for a station the motion due to that model is added to the linear velocity model. Makes sure
to pick out the correct time interval to use.
Args:
site (String): Key saying which site to calculate position for.
Returns:
Array: Positions, one 3-vector for each time epoch.
"""
station_info = self.data[site]
ref_epoch = Time(station_info["ref_epoch"],
scale="utc",
fmt="datetime")
pos = np.zeros((self.time.size, 3))
for pv in station_info["pos_vel"].values():
idx = np.logical_and(self.time.utc.datetime >= pv["start"],
self.time.utc.datetime < pv["end"])
if idx.ndim == 0:
idx = np.array([idx])
if not any(idx):
continue
ref_pos = np.array([pv["STAX"], pv["STAY"], pv["STAZ"]])
ref_vel = np.array([pv["VELX"], pv["VELY"], pv["VELZ"]])
interval_years = (self.time - ref_epoch).jd * Unit.day2julian_years
if isinstance(interval_years, float):
interval_years = np.array([interval_years])
pos[idx, :] = ref_pos + interval_years[idx,
None] * ref_vel[None, :]
ell = ellipsoid.get(config.tech.reference_ellipsoid.str.upper())
pos_trs = Position(np.squeeze(pos),
system="trs",
ellipsoid=ell,
time=self.time)
# Post-seismic deformations, see Appendix C in :cite:'itrf2014'
if "psd" in station_info:
psd = station_info["psd"]
denu = dict(H=np.zeros(self.time.size),
E=np.zeros(self.time.size),
N=np.zeros(self.time.size))
for param in psd.values():
t_0 = Time(param["epoch"], fmt="datetime", scale="utc")
delta_t = (self.time - t_0).jd * Unit.day2julian_years
if isinstance(delta_t, float):
delta_t = np.array([delta_t])
idx = delta_t > 0
for L in "ENH":
aexp = np.array(param.get("AEXP_" + L, list()))
texp = np.array(param.get("TEXP_" + L, list()))
for a, t in zip(aexp, texp):
denu[L][idx] += a * (1 - np.exp(-delta_t[idx] / t))
alog = np.array(param.get("ALOG_" + L, list()))
tlog = np.array(param.get("TLOG_" + L, list()))
for a, t in zip(alog, tlog):
denu[L][idx] += a * np.log(1 + delta_t[idx] / t)
denu = np.vstack((denu["E"], denu["N"], denu["H"])).T
pos_delta = PositionDelta(np.squeeze(denu),
system="enu",
ellipsoid=ell,
ref_pos=pos_trs,
time=self.time)
pos_trs += pos_delta.trs
return np.squeeze(pos_trs)
def _get_time(dset):
"""Determine time field
"""
# TODO hjegei: Workaround -> better would it be if Time object can handle gpsweek as input format!!!
jd_day, jd_frac = gnss.gpssec2jd(dset.gpsweek, dset.gpssec)
return Time(val=jd_day, val2=jd_frac, fmt="jd", scale="gps")
def calculate(stage, dset):
"""
Integrate differential equation of motion of the satellite
Args:
stage: Name of current stage
dset: Dataset containing the data
"""
iterations = config.tech.iterations.int
# Run models adjusting station positions
site.calculate_site("site", dset)
delta_pos = site.add("site", dset)
dset.site_pos[:] = (dset.site_pos.gcrs + delta_pos[0].gcrs).trs
dset.add_float("obs",
val=dset.time_of_flight * constant.c / 2,
unit="meter")
dset.add_float("calc", np.zeros(dset.num_obs), unit="meter")
dset.add_float("residual", np.zeros(dset.num_obs), unit="meter")
dset.add_float("up_leg", np.zeros(dset.num_obs), unit="second")
dset.add_posvel("sat_pos",
np.zeros((dset.num_obs, 6)),
system="gcrs",
time=dset.time)
arc_length = config.tech.arc_length.float
dset.site_pos.other = dset.sat_pos
# First guess for up_leg:
dset.up_leg[:] = dset.time_of_flight / 2
for iter_num in itertools.count(start=1):
log.blank()
log.info(f"Calculating model corrections for iteration {iter_num}")
sat_time_list = dset.obs_time + dset.time_bias + dset.up_leg
apriori_orbit_provider = config.tech.apriori_orbit.str
sat_name = dset.vars["sat_name"]
rundate = dset.analysis["rundate"]
if apriori_orbit_provider:
version = config.tech.apriori_orbit_version.str
log.info(
f"Using external orbits from {apriori_orbit_provider}, version {version}"
)
apriori_orbit = apriori.get(
"orbit",
rundate=rundate + timedelta(days=arc_length),
time=None,
day_offset=6,
satellite=sat_name,
apriori_orbit="slr",
file_key="slr_external_orbits",
)
dset_external = apriori_orbit._read(dset, apriori_orbit_provider,
version)
sat_pos = dset_external.sat_pos.gcrs_pos
t_sec = TimeDelta(
dset_external.time -
Time(datetime(rundate.year, rundate.month, rundate.day),
scale="utc",
fmt="datetime"),
fmt="seconds",
)
t_sec = t_sec.value
else:
sat_pos, sat_vel, t_sec = orbit.calculate_orbit(
datetime(rundate.year, rundate.month, rundate.day),
sat_name,
sat_time_list,
return_full_table=True)
sat_pos_ip, sat_vel_ip = interpolation.interpolate_with_derivative(
np.array(t_sec),
sat_pos,
sat_time_list,
kind="interpolated_univariate_spline")
dset.sat_pos.gcrs[:] = np.concatenate((sat_pos_ip, sat_vel_ip), axis=1)
delay.calculate_delay("kinematic_models", dset)
# We observe the time when an observation is done, and the time of flight of the laser pulse. We estimate
# the up-leg time with Newton's method applied to the equation (8.84) of :cite:'beutler2005' Gerhard Beutler:
# Methods of Celestial Mechanics, Vol I., 2005.
for j in range(0, 4):
reflect_time = dset.time + TimeDelta(
dset.time_bias + dset.up_leg, fmt="seconds", scale="utc")
site_pos_reflect_time = (rotation.trs2gcrs(reflect_time)
@ dset.site_pos.trs.val[:, :, None])[:, :,
0]
sta_sat_vector = dset.sat_pos.gcrs.pos.val - site_pos_reflect_time
unit_vector = sta_sat_vector / np.linalg.norm(sta_sat_vector,
axis=1)[:, None]
rho12 = (np.linalg.norm(sta_sat_vector, axis=1) +
delay.add("kinematic_models", dset)) / constant.c
correction = (-dset.up_leg + rho12) / (
np.ones(dset.num_obs) - np.sum(
unit_vector / constant.c * dset.sat_pos.vel.val, axis=1))
dset.up_leg[:] += correction
sat_time_list = dset.obs_time + dset.time_bias + dset.up_leg
sat_pos_ip, sat_vel_ip = interpolation.interpolate_with_derivative(
np.array(t_sec),
sat_pos,
sat_time_list,
kind="interpolated_univariate_spline")
dset.sat_pos.gcrs[:] = np.concatenate((sat_pos_ip, sat_vel_ip),
axis=1)
delay.calculate_delay("satellite_models", dset)
dset.calc[:] = delay.add("satellite_models", dset)
dset.residual[:] = dset.obs - dset.calc
log.info(
f"{dset.num_obs} observations, residual = {dset.rms('residual'):.4f}"
)
if not apriori_orbit_provider:
orbit.update_orbit(sat_name, dset.site_pos.gcrs, dset.sat_pos.pos,
dset.sat_pos.vel, dset.residual, dset.bin_rms)
dset.write_as(stage=stage, label=iter_num, sat_name=sat_name)
if iter_num >= iterations:
break
def data_handling(dset):
"""Edits data based on SLR handling file
Args:
dset: A Dataset containing model data.
Returns:
Array containing False for observations to throw away
"""
handling = apriori.get("slr_handling_file", time=dset.time)
for station in dset.unique("station"):
# Estimate range bias E
intervals = handling.get(station, {}).get("E", [])
for interval, info in intervals:
start_x, end_x = interval
int_idx = dset.filter(station=station) & (
dset.time.datetime >= start_x) & (dset.time.datetime <= end_x)
if np.any(int_idx):
log.info(
f"ILRS handling: Will estimate range bias for station {station} in interval {start_x}-{end_x} in estimate stage"
)
dset.estimate_range[:] = np.logical_or(int_idx,
dset.estimate_range)
# Apply range bias R
intervals = handling.get(station, {}).get("R", [])
for interval, info in intervals:
start_x, end_x = interval
int_idx = dset.filter(station=station) & (
dset.time.datetime >= start_x) & (dset.time.datetime <= end_x)
if np.any(int_idx):
log.info(
f"ILRS handling: Applying range bias for station {station} in interval {start_x}-{end_x}"
)
RB = info["e_value"]
if info["unit"] == "mm":
dset.range_bias[:] += int_idx * RB * Unit.mm2m
elif info["unit"] == "ms":
dset.range_bias[:] += int_idx * RB * Unit.millisec2seconds * constant.c
else:
log.fatal(
"Unknown unit on ILRS Data handling file for range bias applied"
)
# Estimate time bias U
intervals = handling.get(station, {}).get("U", [])
for interval, info in intervals:
start_x, end_x = interval
int_idx = dset.filter(station=station) & (
dset.time.datetime >= start_x) & (dset.time.datetime <= end_x)
if np.any(int_idx):
log.info(
f"ILRS handling: Will estimate time bias for station {station} in interval {start_x}-{end_x} in estimate stage"
)
dset.estimate_time[:] = np.logical_or(int_idx,
dset.estimate_time)
# Apply time bias T
intervals = handling.get(station, {}).get("T", [])
for interval, info in intervals:
start_x, end_x = interval
int_idx = dset.filter(station=station) & (
dset.time.datetime >= start_x) & (dset.time.datetime <= end_x)
if np.any(int_idx):
log.info(
f"ILRS handling: Applying time bias for station {station} in interval {start_x}-{end_x}"
)
t_midInterval = Time(start_x + 1 / 2 * (end_x - start_x),
fmt="datetime",
scale="utc")
TB = info["e_value"]
drift = info["e_rate"]
if info["unit"] == "us":
time_drifted = (dset.time.datetime -
t_midInterval).jd * drift
dset.time_bias[:] += int_idx * (
-np.repeat(TB, dset.num_obs) -
time_drifted) * Unit.microsec2sec
else:
log.fatal(
"Unknown unit on ILRS Data handling file for time bias applied"
)
# Apply pressure bias P
intervals = handling.get(station, {}).get("P", [])
for interval, info in intervals:
start_x, end_x = interval
int_idx = dset.filter(station=station) & (
dset.time.datetime >= start_x) & (dset.time.datetime <= end_x)
if np.any(int_idx):
log.info(
f"ILRS handling: Applying pressure bias for station {station} in interval {start_x}-{end_x}"
)
PB = info["e_value"]
if info["unit"] == "mB":
dset.pressure[:] += int_idx * PB
else:
log.fatal(
"Unknown unit on ILRS Data handling file for pressure bias applied"
)
# Target signature bias C
intervals = handling.get(station, {}).get("C", [])
for interval, info in intervals:
start_x, end_x = interval
int_idx = dset.filter(station=station) & (
dset.time.datetime >= start_x) & (dset.time.datetime <= end_x)
if np.any(int_idx):
log.fatal(
f"ILRS handling: TODO: Implement target signature bias!")