class Laikad:
def __init__(self,
valid_const=("GPS", "GLONASS"),
auto_fetch_orbits=True,
auto_update=False,
valid_ephem_types=(EphemerisType.ULTRA_RAPID_ORBIT,
EphemerisType.NAV),
save_ephemeris=False,
use_qcom=False):
"""
valid_const: GNSS constellation which can be used
auto_fetch_orbits: If true fetch orbits from internet when needed
auto_update: If true download AstroDog will download all files needed. This can be ephemeris or correction data like ionosphere.
valid_ephem_types: Valid ephemeris types to be used by AstroDog
save_ephemeris: If true saves and loads nav and orbit ephemeris to cache.
"""
self.astro_dog = AstroDog(valid_const=valid_const,
auto_update=auto_update,
valid_ephem_types=valid_ephem_types,
clear_old_ephemeris=True,
cache_dir=DOWNLOADS_CACHE_FOLDER)
self.gnss_kf = GNSSKalman(GENERATED_DIR,
cython=True,
erratic_clock=use_qcom)
self.auto_fetch_orbits = auto_fetch_orbits
self.orbit_fetch_executor: Optional[ProcessPoolExecutor] = None
self.orbit_fetch_future: Optional[Future] = None
self.last_fetch_orbits_t = None
self.got_first_gnss_msg = False
self.last_cached_t = None
self.save_ephemeris = save_ephemeris
self.load_cache()
self.posfix_functions = {
constellation: get_posfix_sympy_fun(constellation)
for constellation in (ConstellationId.GPS, ConstellationId.GLONASS)
}
self.last_pos_fix = []
self.last_pos_residual = []
self.last_pos_fix_t = None
self.use_qcom = use_qcom
def load_cache(self):
if not self.save_ephemeris:
return
cache = Params().get(EPHEMERIS_CACHE)
if not cache:
return
try:
cache = json.loads(cache, object_hook=deserialize_hook)
self.astro_dog.add_orbits(cache['orbits'])
self.astro_dog.add_navs(cache['nav'])
self.last_fetch_orbits_t = cache['last_fetch_orbits_t']
except json.decoder.JSONDecodeError:
cloudlog.exception("Error parsing cache")
timestamp = self.last_fetch_orbits_t.as_datetime(
) if self.last_fetch_orbits_t is not None else 'Nan'
cloudlog.debug(
f"Loaded nav ({sum([len(v) for v in cache['nav']])}) and orbits ({sum([len(v) for v in cache['orbits']])}) cache with timestamp: {timestamp}. Unique orbit and nav sats: {list(cache['orbits'].keys())} {list(cache['nav'].keys())} "
+
f"With time range: {[f'{start.as_datetime()}, {end.as_datetime()}' for (start,end) in self.astro_dog.orbit_fetched_times._ranges]}"
)
def cache_ephemeris(self, t: GPSTime):
if self.save_ephemeris and (self.last_cached_t is None
or t - self.last_cached_t > SECS_IN_MIN):
put_nonblocking(
EPHEMERIS_CACHE,
json.dumps(
{
'version': CACHE_VERSION,
'last_fetch_orbits_t': self.last_fetch_orbits_t,
'orbits': self.astro_dog.orbits,
'nav': self.astro_dog.nav
},
cls=CacheSerializer))
cloudlog.debug("Cache saved")
self.last_cached_t = t
def get_est_pos(self, t, processed_measurements):
if self.last_pos_fix_t is None or abs(self.last_pos_fix_t - t) >= 2:
min_measurements = 6 if any(
p.constellation_id == ConstellationId.GLONASS
for p in processed_measurements) else 5
pos_fix, pos_fix_residual = calc_pos_fix_gauss_newton(
processed_measurements,
self.posfix_functions,
min_measurements=min_measurements)
if len(pos_fix) > 0:
self.last_pos_fix_t = t
residual_median = np.median(np.abs(pos_fix_residual))
if np.median(
np.abs(pos_fix_residual)) < POS_FIX_RESIDUAL_THRESHOLD:
cloudlog.debug(
f"Pos fix is within threshold with median: {residual_median.round()}"
)
self.last_pos_fix = pos_fix[:3]
self.last_pos_residual = pos_fix_residual
else:
cloudlog.debug(
f"Pos fix failed with median: {residual_median.round()}. All residuals: {np.round(pos_fix_residual)}"
)
return self.last_pos_fix
def is_good_report(self, gnss_msg):
if gnss_msg.which == 'drMeasurementReport' and self.use_qcom:
constellation_id = ConstellationId.from_qcom_source(
gnss_msg.drMeasurementReport.source)
# TODO support GLONASS
return constellation_id in [
ConstellationId.GPS, ConstellationId.SBAS
]
elif gnss_msg.which == 'measurementReport' and not self.use_qcom:
return True
else:
return False
def read_report(self, gnss_msg):
if self.use_qcom:
report = gnss_msg.drMeasurementReport
week = report.gpsWeek
tow = report.gpsMilliseconds / 1000.0
new_meas = read_raw_qcom(report)
else:
report = gnss_msg.measurementReport
week = report.gpsWeek
tow = report.rcvTow
new_meas = read_raw_ublox(report)
return week, tow, new_meas
def process_gnss_msg(self, gnss_msg, gnss_mono_time: int, block=False):
if self.is_good_report(gnss_msg):
week, tow, new_meas = self.read_report(gnss_msg)
t = gnss_mono_time * 1e-9
if week > 0:
self.got_first_gnss_msg = True
latest_msg_t = GPSTime(week, tow)
if self.auto_fetch_orbits:
self.fetch_orbits(latest_msg_t, block)
# Filter measurements with unexpected pseudoranges for GPS and GLONASS satellites
new_meas = [
m for m in new_meas if 1e7 < m.observables['C1C'] < 3e7
]
processed_measurements = process_measurements(
new_meas, self.astro_dog)
est_pos = self.get_est_pos(t, processed_measurements)
corrected_measurements = correct_measurements(
processed_measurements, est_pos,
self.astro_dog) if len(est_pos) > 0 else []
if gnss_mono_time % 10 == 0:
cloudlog.debug(
f"Measurements Incoming/Processed/Corrected: {len(new_meas), len(processed_measurements), len(corrected_measurements)}"
)
self.update_localizer(est_pos, t, corrected_measurements)
kf_valid = all(self.kf_valid(t))
ecef_pos = self.gnss_kf.x[GStates.ECEF_POS]
ecef_vel = self.gnss_kf.x[GStates.ECEF_VELOCITY]
p = self.gnss_kf.P.diagonal()
pos_std = np.sqrt(p[GStates.ECEF_POS])
vel_std = np.sqrt(p[GStates.ECEF_VELOCITY])
meas_msgs = [
create_measurement_msg(m) for m in corrected_measurements
]
dat = messaging.new_message("gnssMeasurements")
measurement_msg = log.LiveLocationKalman.Measurement.new_message
dat.gnssMeasurements = {
"gpsWeek":
week,
"gpsTimeOfWeek":
tow,
"positionECEF":
measurement_msg(value=ecef_pos.tolist(),
std=pos_std.tolist(),
valid=kf_valid),
"velocityECEF":
measurement_msg(value=ecef_vel.tolist(),
std=vel_std.tolist(),
valid=kf_valid),
"positionFixECEF":
measurement_msg(value=self.last_pos_fix,
std=self.last_pos_residual,
valid=self.last_pos_fix_t == t),
"ubloxMonoTime":
gnss_mono_time,
"correctedMeasurements":
meas_msgs
}
return dat
# TODO this only works on GLONASS, qcom needs live ephemeris parsing too
elif gnss_msg.which == 'ephemeris':
ephem = convert_ublox_ephem(gnss_msg.ephemeris)
self.astro_dog.add_navs({ephem.prn: [ephem]})
self.cache_ephemeris(t=ephem.epoch)
#elif gnss_msg.which == 'ionoData':
# todo add this. Needed to better correct messages offline. First fix ublox_msg.cc to sent them.
def update_localizer(self, est_pos, t: float,
measurements: List[GNSSMeasurement]):
# Check time and outputs are valid
valid = self.kf_valid(t)
if not all(valid):
if not valid[0]: # Filter not initialized
pass
elif not valid[1]:
cloudlog.error(
"Time gap of over 10s detected, gnss kalman reset")
elif not valid[2]:
cloudlog.error("Gnss kalman filter state is nan")
if len(est_pos) > 0:
cloudlog.info(f"Reset kalman filter with {est_pos}")
self.init_gnss_localizer(est_pos)
else:
return
if len(measurements) > 0:
kf_add_observations(self.gnss_kf, t, measurements)
else:
# Ensure gnss filter is updated even with no new measurements
self.gnss_kf.predict(t)
def kf_valid(self, t: float) -> List[bool]:
filter_time = self.gnss_kf.filter.get_filter_time()
return [
not math.isnan(filter_time),
abs(t - filter_time) < MAX_TIME_GAP,
all(np.isfinite(self.gnss_kf.x[GStates.ECEF_POS]))
]
def init_gnss_localizer(self, est_pos):
x_initial, p_initial_diag = np.copy(GNSSKalman.x_initial), np.copy(
np.diagonal(GNSSKalman.P_initial))
x_initial[GStates.ECEF_POS] = est_pos
p_initial_diag[GStates.ECEF_POS] = 1000**2
self.gnss_kf.init_state(x_initial, covs_diag=p_initial_diag)
def fetch_orbits(self, t: GPSTime, block):
# Download new orbits if 1 hour of orbits data left
if t + SECS_IN_HR not in self.astro_dog.orbit_fetched_times and (
self.last_fetch_orbits_t is None
or abs(t - self.last_fetch_orbits_t) > SECS_IN_MIN):
astro_dog_vars = self.astro_dog.valid_const, self.astro_dog.auto_update, self.astro_dog.valid_ephem_types, self.astro_dog.cache_dir
ret = None
if block: # Used for testing purposes
ret = get_orbit_data(t, *astro_dog_vars)
elif self.orbit_fetch_future is None:
self.orbit_fetch_executor = ProcessPoolExecutor(max_workers=1)
self.orbit_fetch_future = self.orbit_fetch_executor.submit(
get_orbit_data, t, *astro_dog_vars)
elif self.orbit_fetch_future.done():
ret = self.orbit_fetch_future.result()
self.orbit_fetch_executor = self.orbit_fetch_future = None
if ret is not None:
if ret[0] is None:
self.last_fetch_orbits_t = ret[2]
else:
self.astro_dog.orbits, self.astro_dog.orbit_fetched_times, self.last_fetch_orbits_t = ret
self.cache_ephemeris(t=t)
class Laikad:
def __init__(self, valid_const=("GPS", "GLONASS"), auto_update=False, valid_ephem_types=(EphemerisType.ULTRA_RAPID_ORBIT, EphemerisType.NAV),
save_ephemeris=False, last_known_position=None):
self.astro_dog = AstroDog(valid_const=valid_const, auto_update=auto_update, valid_ephem_types=valid_ephem_types, clear_old_ephemeris=True)
self.gnss_kf = GNSSKalman(GENERATED_DIR)
self.orbit_fetch_executor = ProcessPoolExecutor()
self.orbit_fetch_future: Optional[Future] = None
self.last_fetch_orbits_t = None
self.last_cached_t = None
self.save_ephemeris = save_ephemeris
self.load_cache()
self.posfix_functions = {constellation: get_posfix_sympy_fun(constellation) for constellation in (ConstellationId.GPS, ConstellationId.GLONASS)}
self.last_pos_fix = last_known_position if last_known_position is not None else []
self.last_pos_residual = []
self.last_pos_fix_t = None
def load_cache(self):
cache = Params().get(EPHEMERIS_CACHE)
if not cache:
return
try:
cache = json.loads(cache, object_hook=deserialize_hook)
self.astro_dog.add_orbits(cache['orbits'])
self.astro_dog.add_navs(cache['nav'])
self.last_fetch_orbits_t = cache['last_fetch_orbits_t']
except json.decoder.JSONDecodeError:
cloudlog.exception("Error parsing cache")
def cache_ephemeris(self, t: GPSTime):
if self.save_ephemeris and (self.last_cached_t is None or t - self.last_cached_t > SECS_IN_MIN):
put_nonblocking(EPHEMERIS_CACHE, json.dumps(
{'version': CACHE_VERSION, 'last_fetch_orbits_t': self.last_fetch_orbits_t, 'orbits': self.astro_dog.orbits, 'nav': self.astro_dog.nav},
cls=CacheSerializer))
self.last_cached_t = t
def process_ublox_msg(self, ublox_msg, ublox_mono_time: int, block=False):
if ublox_msg.which == 'measurementReport':
t = ublox_mono_time * 1e-9
report = ublox_msg.measurementReport
if report.gpsWeek > 0:
latest_msg_t = GPSTime(report.gpsWeek, report.rcvTow)
self.fetch_orbits(latest_msg_t + SECS_IN_MIN, block)
new_meas = read_raw_ublox(report)
processed_measurements = process_measurements(new_meas, self.astro_dog)
if self.last_pos_fix_t is None or abs(self.last_pos_fix_t - t) >= 2:
min_measurements = 5 if any(p.constellation_id == ConstellationId.GLONASS for p in processed_measurements) else 4
pos_fix, pos_fix_residual = calc_pos_fix_gauss_newton(processed_measurements, self.posfix_functions, min_measurements=min_measurements)
if len(pos_fix) > 0:
self.last_pos_fix = pos_fix[:3]
self.last_pos_residual = pos_fix_residual
self.last_pos_fix_t = t
corrected_measurements = correct_measurements(processed_measurements, self.last_pos_fix, self.astro_dog) if self.last_pos_fix_t is not None else []
self.update_localizer(self.last_pos_fix, t, corrected_measurements)
kf_valid = all(self.kf_valid(t))
ecef_pos = self.gnss_kf.x[GStates.ECEF_POS].tolist()
ecef_vel = self.gnss_kf.x[GStates.ECEF_VELOCITY].tolist()
pos_std = np.sqrt(abs(self.gnss_kf.P[GStates.ECEF_POS].diagonal())).tolist()
vel_std = np.sqrt(abs(self.gnss_kf.P[GStates.ECEF_VELOCITY].diagonal())).tolist()
meas_msgs = [create_measurement_msg(m) for m in corrected_measurements]
dat = messaging.new_message("gnssMeasurements")
measurement_msg = log.LiveLocationKalman.Measurement.new_message
dat.gnssMeasurements = {
"gpsWeek": report.gpsWeek,
"gpsTimeOfWeek": report.rcvTow,
"positionECEF": measurement_msg(value=ecef_pos, std=pos_std, valid=kf_valid),
"velocityECEF": measurement_msg(value=ecef_vel, std=vel_std, valid=kf_valid),
"positionFixECEF": measurement_msg(value=self.last_pos_fix, std=self.last_pos_residual, valid=self.last_pos_fix_t == t),
"ubloxMonoTime": ublox_mono_time,
"correctedMeasurements": meas_msgs
}
return dat
elif ublox_msg.which == 'ephemeris':
ephem = convert_ublox_ephem(ublox_msg.ephemeris)
self.astro_dog.add_navs({ephem.prn: [ephem]})
self.cache_ephemeris(t=ephem.epoch)
# elif ublox_msg.which == 'ionoData':
# todo add this. Needed to better correct messages offline. First fix ublox_msg.cc to sent them.
def update_localizer(self, est_pos, t: float, measurements: List[GNSSMeasurement]):
# Check time and outputs are valid
valid = self.kf_valid(t)
if not all(valid):
if not valid[0]:
cloudlog.info("Init gnss kalman filter")
elif not valid[1]:
cloudlog.error("Time gap of over 10s detected, gnss kalman reset")
elif not valid[2]:
cloudlog.error("Gnss kalman filter state is nan")
if len(est_pos) > 0:
cloudlog.info(f"Reset kalman filter with {est_pos}")
self.init_gnss_localizer(est_pos)
else:
cloudlog.info("Could not reset kalman filter")
return
if len(measurements) > 0:
kf_add_observations(self.gnss_kf, t, measurements)
else:
# Ensure gnss filter is updated even with no new measurements
self.gnss_kf.predict(t)
def kf_valid(self, t: float):
filter_time = self.gnss_kf.filter.filter_time
return [filter_time is not None,
filter_time is not None and abs(t - filter_time) < MAX_TIME_GAP,
all(np.isfinite(self.gnss_kf.x[GStates.ECEF_POS]))]
def init_gnss_localizer(self, est_pos):
x_initial, p_initial_diag = np.copy(GNSSKalman.x_initial), np.copy(np.diagonal(GNSSKalman.P_initial))
x_initial[GStates.ECEF_POS] = est_pos
p_initial_diag[GStates.ECEF_POS] = 1000 ** 2
self.gnss_kf.init_state(x_initial, covs_diag=p_initial_diag)
def fetch_orbits(self, t: GPSTime, block):
if t not in self.astro_dog.orbit_fetched_times and (self.last_fetch_orbits_t is None or t - self.last_fetch_orbits_t > SECS_IN_HR):
astro_dog_vars = self.astro_dog.valid_const, self.astro_dog.auto_update, self.astro_dog.valid_ephem_types
if self.orbit_fetch_future is None:
self.orbit_fetch_future = self.orbit_fetch_executor.submit(get_orbit_data, t, *astro_dog_vars)
if block:
self.orbit_fetch_future.result()
if self.orbit_fetch_future.done():
ret = self.orbit_fetch_future.result()
self.last_fetch_orbits_t = t
if ret:
self.astro_dog.orbits, self.astro_dog.orbit_fetched_times = ret
self.cache_ephemeris(t=t)
self.orbit_fetch_future = None