def parse_baseline_clock_offsets(dset, baseline_clock_offsets, ref_clock):
"""Parsers and validate the baseline clock offsets from the configuration file and add them to list
Args:
dset: Dataset
bco: Baseline clock offsets detected automatically
Returns:
list: baselines to estimate baseline clock offsets for
"""
baselines = dset.unique("baseline")
man_bco = config.tech.get("baseline_clock_offsets", section=MODEL).list
for bl in man_bco:
if bl not in baselines:
log.warn(f"Baseline {bl} in baseline_clock_offsets is unknown. Available options are {', '.join(baselines)}")
else:
baseline_clock_offsets.add(bl)
for bl in list(baseline_clock_offsets):
if ref_clock in bl:
sta_1, _, sta_2 = bl.partition("/")
other_sta = sta_1 if sta_2 == ref_clock else sta_2
other_baselines = dset.unique("baseline", idx=dset.filter(station=other_sta))
if all([other_bl in baseline_clock_offsets for other_bl in other_baselines]):
# Remove the bco for the baseline to the reference clock of all other baselines
# for the same station is also estimated
baseline_clock_offsets.remove(bl)
store_bco = config.tech.get("store_bco", section=MODEL).bool
if store_bco:
rundate = dset.analysis["rundate"]
pipeline = dset.vars["pipeline"]
session = session=dset.vars["session"]
with config.update_tech_config(rundate, pipeline, session=session) as cfg:
cfg.update(MODEL, "baseline_clock_offsets",
", ".join(baseline_clock_offsets),
source=MODEL)
log.info(f"Estimating baseline clock offsets for: {', '.join(baseline_clock_offsets)}")
return baseline_clock_offsets
def calculate(rundate, session, prev_stage, stage):
"""Estimate model parameters
Args:
rundate (Datetime): The model run date.
session (String): Name of session.
prev_stage (String): Name of previous stage.
stage (String): Name of current stage.
"""
dset = data.Dataset(rundate,
tech=TECH,
stage=prev_stage,
dataset_name=session,
dataset_id="last")
dset.delete_from_file(stage=stage, dataset_id="all")
# Run models adjusting station positions
log.info("Calculating station displacements for {}", session)
models.calculate_site("pos_models", dset, shape=(6, ))
delta_pos = np.sum(dset.get_table("pos_models").reshape(
(dset.num_obs, -1, 6)),
axis=1)
gcrs_dpos_1 = delta_pos[:, :3]
gcrs_dvel_1 = (
dset.time.itrs2gcrs_dot
@ dset.site_pos_1.convert_gcrs_to_itrs(gcrs_dpos_1)[:, :, None])[:, :,
0]
dset.site_pos_1.add_to_gcrs(
np.concatenate((gcrs_dpos_1, gcrs_dvel_1), axis=1))
gcrs_dpos_2 = delta_pos[:, 3:]
gcrs_dvel_2 = (
dset.time.itrs2gcrs_dot
@ dset.site_pos_2.convert_gcrs_to_itrs(gcrs_dpos_2)[:, :, None])[:, :,
0]
dset.site_pos_2.add_to_gcrs(
np.concatenate((gcrs_dpos_2, gcrs_dvel_2), axis=1))
log.blank()
# Run models for each term of the observation equation
log.info("Calculating theoretical delays for {}", session)
models.calculate_delay("calc_models", dset)
dset.add_float("obs",
val=dset.observed_delay,
unit="meter",
write_level="operational")
dset.add_float("calc",
val=np.sum(dset.get_table("calc_models"), axis=1),
unit="meter",
write_level="operational")
dset.add_float("residual",
val=dset.obs - dset.calc,
unit="meter",
write_level="operational")
log.blank()
# Estimate clock polynomial
log.info("Calculating clock polynomials for {}", session)
max_iterations = config.tech.calculate_max_iterations.int
outlier_limit = config.tech.calculate_outlier_limit.float
store_outliers = config.tech.store_outliers.bool
for iter_num in itertools.count(start=1):
models.calculate_delay("correction_models", dset, dset)
dset.calc[:] = np.sum(np.hstack((dset.get_table("calc_models"),
dset.get_table("correction_models"))),
axis=1)
dset.residual[:] = dset.obs - dset.calc
rms = dset.rms("residual")
log.info("{}: {} observations, residual = {:.4f}", session,
dset.num_obs, rms)
# Store results
dset.write_as(stage=stage, dataset_id=iter_num - 1)
# Detect and remove extreme outliers
idx = np.abs(dset.residual) < outlier_limit * rms
if iter_num > max_iterations or idx.all():
break
if store_outliers:
bad_idx = np.logical_not(idx)
log.info(
f"Adding {np.sum(bad_idx)} observations to ignore_observation")
bad_obs = np.char.add(np.char.add(dset.time.utc.iso[bad_idx], " "),
dset.baseline[bad_idx]).tolist()
with config.update_tech_config(rundate, TECH, session) as cfg:
current = cfg.ignore_observation.observations.as_list(", *")
updated = ", ".join(sorted(current + bad_obs))
cfg.update("ignore_observation",
"observations",
updated,
source=util.get_program_name())
dset.subset(idx)
log.info("Removing {} observations with residuals bigger than {:.4f}",
sum(np.logical_not(idx)), outlier_limit * rms)
log.blank()
# Try to detect clock breaks
if config.tech.detect_clockbreaks.bool:
writers.write_one("vlbi_detect_clockbreaks", dset)
dset.write()
def update_dataset(self, dset, param_names, normal_idx, num_unknowns):
"""Update the given dataset with results from the filtering
Args:
dset (Dataset): The dataset.
param_names (List): Strings with names of parameters. Used to form field names.
normal_idx (Slice): Slice denoting which parameters should be used for the normal equations.
num_unknowns (Int): Number of unknowns.
"""
# Update dataset with state and estimation fields and calculate new residuals
self._add_fields(dset, param_names)
dset.residual[:] = dset.estimate - (dset.obs - dset.calc)
num_unknowns += dset.meta.get("num_clock_coeff", 0)
# Calculate normal equations, and add statistics about estimation to dataset
N, b = self._normal_equations(normal_idx, dset.num_obs - 1)
g = self.x_hat[dset.num_obs - 1, normal_idx, :]
deg_freedom = dset.num_obs - num_unknowns
v = dset.residual[:, None]
P = np.diag(1 / self.r[:dset.num_obs])
sq_sum_residuals = np.asscalar(v.T @ P @ v)
sq_sum_omc_terms = np.asscalar(2 * b.T @ g - g.T @ N @ g)
variance_factor = sq_sum_residuals / deg_freedom if deg_freedom != 0 else np.inf
log.info("Variance factor = {:.4f}, degrees of freedom = {:d}",
variance_factor, deg_freedom)
# Report and set analysis status if there are too few degrees of freedom
if deg_freedom < 1:
log.error(
f"Degrees of freedom is {deg_freedom} < 1. Estimate fewer parameters"
)
if dset.meta.get("analysis_status") == "unchecked":
dset.meta["analysis_status"] = "too few degrees of freedom"
# Update config
# with config.update_tech_config(dset.rundate, dset.vars["tech"], dset.vars["session"]) as cfg:
# cfg.update("analysis_status", "status", dset.meta["analysis_status"], source=__file__)
else:
if dset.meta.get(
"analysis_status") == "too few degrees of freedom":
dset.meta["analysis_status"] = "unchecked"
# Update config
# with config.update_tech_config(dset.rundate, dset.vars["tech"], dset.vars["session"]) as cfg:
# cfg.update("analysis_status", "status", dset.meta["analysis_status"], source=__file__)
# Report and set analysis status if there are too few stations
# TODO: if vlbi_site_pos in state_vector and num_stations < 3
estimate_site_pos = np.char.startswith(np.array(param_names),
"vlbi_site_pos").any()
if len(dset.unique("station")) < 3 and estimate_site_pos:
log.error(
f"Too few stations {len(dset.unique('station'))} < 3. Do not estimate station positions."
)
if dset.meta.get("analysis_status") == "unchecked":
dset.meta["analysis_status"] = "needs custom state vector"
elif len(dset.unique("station")) < 3 and estimate_site_pos:
if dset.meta.get("analysis_status") == "needs custom state vector":
dset.meta["analysis_status"] = "unchecked"
# Update config
with config.update_tech_config(dset.rundate, dset.vars["tech"],
dset.vars["session"]) as cfg:
cfg.update("analysis_status",
"status",
dset.meta.get("analysis_status", ""),
source=__file__)
# Add information to dset.meta
dset.add_to_meta("statistics", "number of observations", dset.num_obs)
dset.add_to_meta("statistics", "number of unknowns", num_unknowns)
dset.add_to_meta("statistics", "square sum of residuals",
sq_sum_residuals)
dset.add_to_meta("statistics", "degrees of freedom", deg_freedom)
dset.add_to_meta("statistics", "variance factor", variance_factor)
dset.add_to_meta("statistics", "weighted square sum of o-c",
sq_sum_residuals + sq_sum_omc_terms)
dset.add_to_meta("normal equation", "matrix", N.tolist())
dset.add_to_meta("normal equation", "vector", b[:, 0].tolist())
dset.add_to_meta("normal equation", "names", param_names[normal_idx])
dset.add_to_meta("normal equation", "unit", [
config.tech[f.split("-")[0]].unit.str
for f in param_names[normal_idx]
])
# TODO should this be here?
log.info("Solving normal equations")
names = dset.meta["normal equation"]["names"]
n = len(names)
d = np.zeros((n, 6))
stations = set()
reference_frame = config.tech.reference_frames.list[0]
from where import apriori
trf = apriori.get("trf",
time=dset.time.utc.mean,
reference_frames=reference_frame)
# thaller2008: eq 2.51 (skipping scale factor)
for idx, column in enumerate(names):
if "_site_pos-" not in column:
continue
station = column.split("-", maxsplit=1)[-1].rsplit("_",
maxsplit=1)[0]
site_id = dset.meta[station]["site_id"]
if site_id in trf:
x0, y0, z0 = trf[
site_id].pos.itrs # TODO: Take units into account
if column.endswith("_x"):
d[idx, :] = np.array([1, 0, 0, 0, z0, -y0])
if column.endswith("_y"):
d[idx, :] = np.array([0, 1, 0, -z0, 0, x0])
if column.endswith("_z"):
d[idx, :] = np.array([0, 0, 1, y0, -x0, 0])
stations.add(station)
log.info("Applying NNT/NNR with {} from {}", ", ".join(stations),
reference_frame.upper())
# thaller2008: eq 2.57
try:
H = np.linalg.inv(d.T @ d) @ d.T
except np.linalg.LinAlgError:
H = np.zeros((6, n))
sigmas = [0.0001] * 3 + [1.5e-11] * 3
# NNR to CRF
if "celestial_reference_frames" in config.tech.master_section:
celestial_reference_frame = config.tech.celestial_reference_frames.list[
0]
crf = apriori.get(
"crf",
celestial_reference_frames=celestial_reference_frame,
session=dset.dataset_name)
H2 = np.zeros((3, n))
for idx, column in enumerate(names):
if "_src_dir-" not in column:
continue
source = column.split("-", maxsplit=1)[-1].split("_")[0]
if source in crf:
ra = crf[source].pos.crs[0]
dec = crf[source].pos.crs[1]
if column.endswith("_ra"):
H2[0, idx] = -np.cos(ra) * np.sin(dec) * np.cos(dec)
H2[1, idx] = -np.sin(ra) * np.sin(dec) * np.cos(dec)
H2[2, idx] = np.cos(dec)**2
if column.endswith("_dec"):
H2[0, idx] = np.sin(ra)
H2[1, idx] = -np.cos(ra)
if H2.any():
log.info("Applying NNR constraint to {}",
celestial_reference_frame.upper())
# add NNR to CRF constraints
H = np.concatenate((H, H2))
sigmas = sigmas + [1e-6] * 3
# thaller2008: eq 2.45
P_h = np.diag(1 / np.array(sigmas)**2)
# thaller2008: eq 2.58
N_h = N + H.T @ P_h @ H
# solve neq
N_h_inv = np.linalg.inv(N_h)
x = N_h_inv @ b
# Covariance: thaller2008: eq 2.16
Q_xx = variance_factor**2 * N_h_inv
dset.add_to_meta("normal equation", "solution", x[:, 0].tolist())
dset.add_to_meta("normal equation", "covariance", Q_xx.tolist())
def calculate(stage, dset):
"""Estimate model parameters
Args:
rundate (Datetime): The model run date.
session (String): Name of session.
prev_stage (String): Name of previous stage.
stage (String): Name of current stage.
"""
# Run models adjusting station positions
log.info(f"Calculating station displacements")
site.calculate_site("site", dset)
delta_pos = site.add("site", dset)
dset.site_pos_1[:] = (dset.site_pos_1.gcrs + delta_pos[0].gcrs).trs
dset.site_pos_2[:] = (dset.site_pos_2.gcrs + delta_pos[1].gcrs).trs
log.blank()
# Run models for each term of the observation equation
log.info(f"Calculating theoretical delays")
delay.calculate_delay("delay", dset)
delta_delay = delay.add("delay", dset)
dset.add_float("obs",
val=dset.observed_delay,
unit="meter",
write_level="operational")
dset.add_float("calc",
val=delta_delay,
unit="meter",
write_level="operational")
dset.add_float("residual",
val=dset.obs - dset.calc,
unit="meter",
write_level="operational")
log.blank()
# Estimate clock polynomial
log.info(f"Calculating clock polynomials")
max_iterations = config.tech.calculate_max_iterations.int
outlier_limit = config.tech.calculate_outlier_limit.float
store_outliers = config.tech.store_outliers.bool
for iter_num in itertools.count(start=1):
delay.calculate_delay("delay_corr", dset, dset)
delta_correction = delay.add("delay_corr", dset)
dset.calc[:] = dset.calc + delta_correction
dset.residual[:] = dset.obs - dset.calc
rms = dset.rms("residual")
log.info(f"{dset.num_obs} observations, residual = {rms:.4f}")
# Store results
dset.write_as(stage=stage, label=iter_num - 1)
# Detect and remove extreme outliers
idx = np.abs(dset.residual) < outlier_limit * rms
if iter_num > max_iterations or idx.all():
break
if store_outliers:
bad_idx = np.logical_not(idx)
log.info(
f"Adding {np.sum(bad_idx)} observations to ignore_observation")
bad_obs = np.char.add(np.char.add(dset.time.utc.iso[bad_idx], " "),
dset.baseline[bad_idx]).tolist()
with config.update_tech_config(
dset.analysis["rundate"],
pipeline,
session=dset.vars["session"]) as cfg:
current = cfg.ignore_observation.observations.as_list(", *")
updated = ", ".join(sorted(current + bad_obs))
cfg.update("ignore_observation",
"observations",
updated,
source=util.get_program_name())
dset.subset(idx)
log.info(
f"Removing {sum(~idx)} observations with residuals bigger than {outlier_limit * rms}"
)
log.blank()
# Try to detect clock breaks
if config.tech.detect_clockbreaks.bool:
writers.write_one("vlbi_detect_clockbreaks", dset=dset)
dset.write()
def update_dataset(self, dset, param_names, normal_idx, num_unknowns):
"""Update the given dataset with results from the filtering
Args:
dset (Dataset): The dataset.
param_names (List): Strings with names of parameters. Used to form field names.
normal_idx (Slice): Slice denoting which parameters should be used for the normal equations.
num_unknowns (Int): Number of unknowns.
"""
# Update dataset with state and estimation fields and calculate new residuals
self._add_fields(dset, param_names)
dset.residual[:] = dset.est - (dset.obs - dset.calc)
num_unknowns += dset.meta.get("num_clock_coeff", 0)
# Calculate normal equations, and add statistics about estimation to dataset
N, b = self._normal_equations(normal_idx, dset.num_obs - 1)
g = self.x_hat[dset.num_obs - 1, normal_idx, :]
deg_freedom = dset.num_obs - num_unknowns
v = dset.residual[:, None]
P = np.diag(1 / self.r[:dset.num_obs])
sq_sum_residuals = np.asscalar(v.T @ P @ v)
sq_sum_omc_terms = np.asscalar(2 * b.T @ g - g.T @ N @ g)
variance_factor = sq_sum_residuals / deg_freedom if deg_freedom != 0 else np.inf
log.info(
f"Variance factor = {variance_factor:.4f}, degrees of freedom = {deg_freedom:d}"
)
# Report and set analysis status if there are too few degrees of freedom
if deg_freedom < 1:
log.error(
f"Degrees of freedom is {deg_freedom} < 1. Estimate fewer parameters"
)
if dset.meta.get("analysis_status") == "unchecked":
dset.meta["analysis_status"] = "too few degrees of freedom"
else:
if dset.meta.get(
"analysis_status") == "too few degrees of freedom":
dset.meta["analysis_status"] = "unchecked"
# Report and set analysis status if there are too few stations
# TODO: if vlbi_site_pos in state_vector and num_stations < 3
estimate_site_pos = np.char.startswith(
np.array(param_names, dtype=str), "vlbi_site_pos").any()
if len(dset.unique("station")) < 3 and estimate_site_pos:
log.warn(
f"Too few stations {len(dset.unique('station'))} < 3. Do not estimate station positions."
)
# if dset.meta.get("analysis_status") == "unchecked":
# dset.meta["analysis_status"] = "needs custom state vector"
elif len(dset.unique("station")) < 3 and estimate_site_pos:
if dset.meta.get("analysis_status") == "needs custom state vector":
dset.meta["analysis_status"] = "unchecked"
# Update config
cfg_vars = dset.vars.copy()
cfg_vars.pop("rundate")
with config.update_tech_config(dset.analysis["rundate"],
cfg_vars.pop("pipeline"),
**cfg_vars) as cfg:
cfg.update("analysis_status",
"status",
dset.meta.get("analysis_status", ""),
source=__file__)
# Add information to dset.meta
dset.meta.add("number of observations",
dset.num_obs,
section="statistics")
dset.meta.add("number of unknowns", num_unknowns, section="statistics")
dset.meta.add("square sum of residuals",
sq_sum_residuals,
section="statistics")
dset.meta.add("degrees of freedom", deg_freedom, section="statistics")
dset.meta.add("variance factor", variance_factor, section="statistics")
dset.meta.add("weighted square sum of o-c",
sq_sum_residuals + sq_sum_omc_terms,
section="statistics")
dset.meta.add("matrix", N.tolist(), section="normal equation")
dset.meta.add("vector", b[:, 0].tolist(), section="normal equation")
dset.meta.add("names",
param_names[normal_idx],
section="normal equation")
dset.meta.add("unit", [
config.tech[f.split("-")[0]].unit.str
for f in param_names[normal_idx]
],
section="normal equation")
def update_dataset(self, dset, param_names, normal_idx, num_unknowns):
"""Update the given dataset with results from the filtering
Args:
dset (Dataset): The dataset.
param_names (List): Strings with names of parameters. Used to form field names.
normal_idx (Slice): Slice denoting which parameters should be used for the normal equations.
num_unknowns (Int): Number of unknowns.
"""
# Update dataset with state and estimation fields and calculate new residuals
self._add_fields(dset, param_names)
dset.residual[:] = dset.est - (dset.obs - dset.calc)
num_unknowns += dset.meta.get("num_clock_coeff", 0)
# Calculate normal equations, and add statistics about estimation to dataset
N, b = self._normal_equations(normal_idx, dset.num_obs - 1)
g = self.x_hat[dset.num_obs - 1, normal_idx, :]
deg_freedom = dset.num_obs - num_unknowns
v = dset.residual[:, None]
P = np.diag(1 / self.r[:dset.num_obs])
sq_sum_residuals = np.asscalar(v.T @ P @ v)
sq_sum_omc_terms = np.asscalar(2 * b.T @ g - g.T @ N @ g)
variance_factor = sq_sum_residuals / deg_freedom if deg_freedom != 0 else np.inf
log.info(
f"Variance factor = {variance_factor:.4f}, degrees of freedom = {deg_freedom:d}"
)
# Report and set analysis status if there are too few degrees of freedom
if deg_freedom < 1:
log.error(
f"Degrees of freedom is {deg_freedom} < 1. Estimate fewer parameters"
)
if dset.meta.get("analysis_status") == "unchecked":
dset.meta["analysis_status"] = "too few degrees of freedom"
else:
if dset.meta.get(
"analysis_status") == "too few degrees of freedom":
dset.meta["analysis_status"] = "unchecked"
# Report and set analysis status if there are too few stations
# TODO: if vlbi_site_pos in state_vector and num_stations < 3
estimate_site_pos = np.char.startswith(
np.array(param_names, dtype=str), "vlbi_site_pos").any()
if len(dset.unique("station")) < 3 and estimate_site_pos:
log.warn(
f"Too few stations {len(dset.unique('station'))} < 3. Do not estimate station positions."
)
# if dset.meta.get("analysis_status") == "unchecked":
# dset.meta["analysis_status"] = "needs custom state vector"
elif len(dset.unique("station")) < 3 and estimate_site_pos:
if dset.meta.get("analysis_status") == "needs custom state vector":
dset.meta["analysis_status"] = "unchecked"
# Update config
cfg_vars = dset.vars.copy()
cfg_vars.pop("rundate")
with config.update_tech_config(dset.analysis["rundate"],
cfg_vars.pop("pipeline"),
**cfg_vars) as cfg:
cfg.update("analysis_status",
"status",
dset.meta.get("analysis_status", ""),
source=__file__)
# Add information to dset.meta
dset.meta.add("number of observations",
dset.num_obs,
section="statistics")
dset.meta.add("number of unknowns", num_unknowns, section="statistics")
dset.meta.add("square sum of residuals",
sq_sum_residuals,
section="statistics")
dset.meta.add("degrees of freedom", deg_freedom, section="statistics")
dset.meta.add("variance factor", variance_factor, section="statistics")
dset.meta.add("weighted square sum of o-c",
sq_sum_residuals + sq_sum_omc_terms,
section="statistics")
dset.meta.add("matrix", N.tolist(), section="normal equation")
dset.meta.add("vector", b[:, 0].tolist(), section="normal equation")
dset.meta.add("names",
param_names[normal_idx],
section="normal equation")
dset.meta.add("unit", [
config.tech[f.split("-")[0]].unit.str
for f in param_names[normal_idx]
],
section="normal equation")
# TODO should this be here?
log.info("Solving normal equations")
names = dset.meta["normal equation"]["names"]
n = len(names)
d = np.zeros((n, 6))
fix_param_weight = np.zeros(n)
H = np.zeros((6, n))
stations = set()
from where import apriori
reference_frame = config.tech.reference_frames.list[0]
trf = apriori.get("trf",
time=dset.time.utc.mean,
reference_frames=reference_frame)
# thaller2008: eq 2.51 (skipping scale factor)
for idx, column in enumerate(names):
if "_site_pos-" not in column:
continue
station = column.split("-", maxsplit=1)[-1].rsplit("_",
maxsplit=1)[0]
site_id = dset.meta[station]["site_id"]
if site_id in trf:
x0, y0, z0 = trf[site_id].pos.trs
if column.endswith("_x"):
d[idx, :] = np.array([1, 0, 0, 0, z0, -y0])
if column.endswith("_y"):
d[idx, :] = np.array([0, 1, 0, -z0, 0, x0])
if column.endswith("_z"):
d[idx, :] = np.array([0, 0, 1, y0, -x0, 0])
stations.add(station)
if len(stations) >= 3:
try:
# thaller2008: eq 2.57
H = np.linalg.inv(d.T @ d) @ d.T
log.info(
f"Applying NNT/NNR with {', '.join(stations)} from {reference_frame.upper()}"
)
except np.linalg.LinAlgError:
log.warn(f"Unable to invert matrix for NNR/NNT constraints")
else:
log.info(
f"Too few stations to use NNR/NNT contraints from {reference_frame.upper()}. Using absolute constraints for station positions."
)
# Too few stations to use NNT/NNR?
for idx, column in enumerate(names):
if "_site_pos-" not in column:
continue
station = column.split("-",
maxsplit=1)[-1].rsplit("_",
maxsplit=1)[0]
fix_param_weight[idx] = 1 / (1e-6)**2 # 1/meters**2
sigmas = [0.0001] * 3 + [1.5e-11] * 3
# NNR to CRF
if "celestial_reference_frames" in config.tech.master_section:
celestial_reference_frame = config.tech.celestial_reference_frames.list[
0]
crf = apriori.get(
"crf",
time=dset.time,
celestial_reference_frames=celestial_reference_frame)
H2 = np.zeros((3, n))
for idx, column in enumerate(names):
if "_src_dir-" not in column:
continue
source = column.split("-", maxsplit=1)[-1].split("_")[0]
if source in crf:
ra = crf[source].pos.right_ascension
dec = crf[source].pos.declination
if dset.num(source=source) < 5:
fix_param_weight[idx] = 1 / (1e-12)**2 # 1/radians**2
if column.endswith("_ra"):
log.info(
f"Too few observations for source {source}. Using absolute constraints for source positions."
)
continue
if column.endswith("_ra"):
H2[0, idx] = -np.cos(ra) * np.sin(dec) * np.cos(dec)
H2[1, idx] = -np.sin(ra) * np.sin(dec) * np.cos(dec)
H2[2, idx] = np.cos(dec)**2
if column.endswith("_dec"):
H2[0, idx] = np.sin(ra)
H2[1, idx] = -np.cos(ra)
if H2.any():
log.info(
f"Applying NNR constraint to {celestial_reference_frame.upper()}"
)
# add NNR to CRF constraints
H = np.concatenate((H, H2))
sigmas = sigmas + [1e-6] * 3
# thaller2008: eq 2.45
P_h = np.diag(1 / np.array(sigmas)**2)
# Free network constraints: thaller2008: eq 2.58
N_h = N + H.T @ P_h @ H
# Baselines with too few obs?
for idx, column in enumerate(names):
if "_baseline-" not in column:
continue
baseline = column.split("-", maxsplit=1)[-1].rsplit("_",
maxsplit=1)[0]
if dset.num(baseline=baseline) < 5:
fix_param_weight[idx] = 1 / (1e-6)**2 # 1/meters**2
log.info(
f"Too few observations for baseline {baseline}. Constrained to a priori value"
)
continue
# Absolute constraints (on sources with too few observations): thaller2008: eq.2.49
N_h += np.diag(fix_param_weight)
# solve neq
N_h_inv = np.linalg.inv(N_h)
x = N_h_inv @ b
# Covariance: thaller2008: eq 2.16
Q_xx = variance_factor**2 * N_h_inv
dset.meta.add("solution", x[:, 0].tolist(), section="normal equation")
dset.meta.add("covariance", Q_xx.tolist(), section="normal equation")
