Files
dragonpilot/laika/raw_gnss.py
dragonpilot 07efb69074 dragonpilot beta3
date: 2023-08-14T18:35:32
commit: 90b4f6596bf852f4add5a8faa7581aabb57e4ba4
2023-08-14 18:35:39 +08:00

336 lines
14 KiB
Python

from math import sqrt
from typing import Dict, List, Optional, Union
import numpy as np
import datetime
import struct
from . import constants
from .ephemeris import Ephemeris
from .lib.coordinates import LocalCoord
from .gps_time import GPSTime
from .helpers import ConstellationId, get_constellation_and_sv_id, get_nmea_id_from_constellation_and_svid, \
rinex3_obs_from_rinex2_obs
def array_from_normal_meas(meas):
return np.concatenate(([meas.get_nmea_id()],
[meas.recv_time_week],
[meas.recv_time_sec],
[meas.glonass_freq],
[meas.observables['C1C']],
[meas.observables_std['C1C']],
[meas.observables['D1C']],
[meas.observables_std['D1C']],
[meas.observables['S1C']],
[meas.observables['L1C']]))
def normal_meas_from_array(arr):
observables, observables_std = {}, {}
observables['C1C'] = arr[4]
observables_std['C1C'] = arr[5]
observables['D1C'] = arr[6]
observables_std['D1C'] = arr[7]
observables['S1C'] = arr[8]
observables['L1C'] = arr[9]
constellation_id, sv_id = get_constellation_and_sv_id(nmea_id=arr[0])
return GNSSMeasurement(constellation_id, sv_id, arr[1], arr[2],
observables, observables_std, arr[3])
class GNSSMeasurement:
PRN = 0
RECV_TIME_WEEK = 1
RECV_TIME_SEC = 2
GLONASS_FREQ = 3
PR = 4
PR_STD = 5
PRR = 6
PRR_STD = 7
SAT_POS = slice(8, 11)
SAT_VEL = slice(11, 14)
def __init__(self, constellation_id: ConstellationId, sv_id: int, recv_time_week: int, recv_time_sec: float, observables: Dict[str, float],
observables_std: Dict[str, float], glonass_freq: Union[int, float, None] = None):
# Metadata
# prn: unique satellite id
self.prn = "%s%02d" % (constellation_id.to_rinex_char(), sv_id) # satellite ID in rinex convention
self.constellation_id = constellation_id
self.sv_id = sv_id # satellite id per constellation
self.recv_time_week = recv_time_week
self.recv_time_sec = recv_time_sec
self.recv_time = GPSTime(recv_time_week, recv_time_sec)
self.glonass_freq = glonass_freq # glonass channel
# Measurements
self.observables = observables
self.observables_std = observables_std
# flags
self.processed = False
self.corrected = False
# sat info
self.sat_pos = np.array([np.nan, np.nan, np.nan])
self.sat_vel = np.array([np.nan, np.nan, np.nan])
self.sat_clock_err = np.nan
self.sat_ephemeris: Optional[Ephemeris] = None
self.sat_pos_final = np.array([np.nan, np.nan, np.nan]) # sat_pos in receiver time's ECEF frame instead of satellite time's ECEF frame
self.observables_final: Dict[str, float] = {}
def process(self, dog):
sat_time = self.recv_time - self.observables['C1C']/constants.SPEED_OF_LIGHT
sat_info = dog.get_sat_info(self.prn, sat_time)
if sat_info is None:
return False
self.sat_pos, self.sat_vel, self.sat_clock_err, _, self.sat_ephemeris = sat_info
self.processed = True
return True
def correct(self, est_pos, dog, correct_delay=True):
for obs in self.observables:
if obs[0] == 'C': # or obs[0] == 'L':
if correct_delay:
delay = dog.get_delay(self.prn, self.recv_time, est_pos, signal=obs)
else:
delay = 0.0
if delay is not None:
self.observables_final[obs] = (self.observables[obs] +
self.sat_clock_err*constants.SPEED_OF_LIGHT -
delay)
else:
self.observables_final[obs] = self.observables[obs]
if 'C1C' in self.observables_final and 'C2P' in self.observables_final:
self.observables_final['IOF'] = (((constants.GPS_L1**2)*self.observables_final['C1C'] -
(constants.GPS_L2**2)*self.observables_final['C2P'])/
(constants.GPS_L1**2 - constants.GPS_L2**2))
geometric_range = np.linalg.norm(self.sat_pos - est_pos)
theta_1 = constants.EARTH_ROTATION_RATE * geometric_range / constants.SPEED_OF_LIGHT
self.sat_pos_final = np.array([self.sat_pos[0] * np.cos(theta_1) + self.sat_pos[1] * np.sin(theta_1),
self.sat_pos[1] * np.cos(theta_1) - self.sat_pos[0] * np.sin(theta_1),
self.sat_pos[2]])
if 'C1C' in self.observables_final and np.isfinite(self.observables_final['C1C']):
self.corrected = True
return True
return False
def as_array(self, only_corrected=True):
observables = self.observables_final
sat_pos = self.sat_pos_final
if not self.corrected:
if only_corrected:
raise NotImplementedError('Only corrected measurements can be put into arrays')
else:
observables = self.observables
sat_pos = self.sat_pos
ret = np.array([self.get_nmea_id(), self.recv_time_week, self.recv_time_sec, self.glonass_freq,
observables['C1C'], self.observables_std['C1C'],
observables['D1C'], self.observables_std['D1C']])
return np.concatenate((ret, sat_pos, self.sat_vel))
def __repr__(self):
time = self.recv_time.as_datetime().strftime('%Y-%m-%dT%H:%M:%S.%f')
return f"<GNSSMeasurement from {self.prn} at {time}>"
def get_nmea_id(self):
return get_nmea_id_from_constellation_and_svid(self.constellation_id, self.sv_id)
def process_measurements(measurements: List[GNSSMeasurement], dog) -> List[GNSSMeasurement]:
proc_measurements = []
for meas in measurements:
if meas.process(dog):
proc_measurements.append(meas)
return proc_measurements
def correct_measurements(measurements: List[GNSSMeasurement], est_pos, dog, correct_delay=True) -> List[GNSSMeasurement]:
corrected_measurements = []
for meas in measurements:
if meas.correct(est_pos, dog, correct_delay=correct_delay):
corrected_measurements.append(meas)
return corrected_measurements
def group_measurements_by_epoch(measurements):
meas_filt_by_t = [[measurements[0]]]
for m in measurements[1:]:
if abs(m.recv_time - meas_filt_by_t[-1][-1].recv_time) > 1e-9:
meas_filt_by_t.append([])
meas_filt_by_t[-1].append(m)
return meas_filt_by_t
def group_measurements_by_sat(measurements):
measurements_by_sat = {}
sats = {m.prn for m in measurements}
for sat in sats:
measurements_by_sat[sat] = [m for m in measurements if m.prn == sat]
return measurements_by_sat
def read_raw_qcom(report):
dr = 'DrMeasurementReport' in str(report.schema)
# Only gps/sbas and glonass are supported
constellation_id = ConstellationId.from_qcom_source(report.source)
if constellation_id in [ConstellationId.GPS, ConstellationId.SBAS]: # gps/sbas
if dr:
recv_tow = report.gpsMilliseconds / 1000.0 # seconds
time_bias_ms = struct.unpack("f", struct.pack("I", report.gpsTimeBiasMs))[0]
else:
recv_tow = report.milliseconds / 1000.0 # seconds
time_bias_ms = report.timeBias
recv_time = GPSTime(report.gpsWeek, recv_tow)
elif constellation_id == ConstellationId.GLONASS:
if dr:
recv_tow = report.glonassMilliseconds / 1000.0 # seconds
recv_time = GPSTime.from_glonass(report.glonassYear, report.glonassDay, recv_tow)
time_bias_ms = report.glonassTimeBias
else:
recv_tow = report.milliseconds / 1000.0 # seconds
recv_time = GPSTime.from_glonass(report.glonassCycleNumber, report.glonassNumberOfDays, recv_tow)
time_bias_ms = report.timeBias
else:
raise NotImplementedError('Only GPS (0), SBAS (1) and GLONASS (6) are supported from qcom, not:', {report.source})
# logging.debug(recv_time, report.source, time_bias_ms, dr)
measurements = []
for i in report.sv:
# todo change svId to nmea_id in cereal message. Or better: change the publisher to publish correct svId's, since constellation id is also given
nmea_id = i.svId
if nmea_id == 255:
# TODO nmea_id is not valid. Fix publisher
continue
_, sv_id = get_constellation_and_sv_id(nmea_id)
if not i.measurementStatus.measurementNotUsable and i.measurementStatus.satelliteTimeIsKnown:
sat_tow = (i.unfilteredMeasurementIntegral + i.unfilteredMeasurementFraction + i.latency + time_bias_ms) / 1000
observables, observables_std = {}, {}
observables['C1C'] = (recv_tow - sat_tow)*constants.SPEED_OF_LIGHT
observables_std['C1C'] = i.unfilteredTimeUncertainty * 1e-3 * constants.SPEED_OF_LIGHT
if i.measurementStatus.fineOrCoarseVelocity:
# about 10x better, perhaps filtered with carrier phase?
observables['D1C'] = i.fineSpeed
observables_std['D1C'] = i.fineSpeedUncertainty
else:
observables['D1C'] = i.unfilteredSpeed
observables_std['D1C'] = i.unfilteredSpeedUncertainty
observables['S1C'] = (i.carrierNoise/100.) if i.carrierNoise != 0 else np.nan
observables['L1C'] = np.nan
# logging.debug(" %.5f %3d %10.2f %7.2f %7.2f %.2f %d" % (recv_time.tow, nmea_id,
# observables['C1C'], observables_std['C1C'],
# observables_std['D1C'], observables['S1C'], i.latency), i.observationState, i.measurementStatus.fineOrCoarseVelocity)
glonass_freq = (i.glonassFrequencyIndex - 7) if constellation_id == ConstellationId.GLONASS else np.nan
measurements.append(GNSSMeasurement(constellation_id, sv_id,
recv_time.week,
recv_time.tow,
observables,
observables_std,
glonass_freq))
return measurements
def read_raw_ublox(report) -> List[GNSSMeasurement]:
recv_tow = report.rcvTow # seconds
recv_week = report.gpsWeek
measurements = []
for i in report.measurements:
# only add Gps and Glonass fixes
if i.gnssId in [ConstellationId.GPS, ConstellationId.GLONASS]:
if i.svId > 32 or i.pseudorange > 2**32:
continue
observables = {}
observables_std = {}
if i.trackingStatus.pseudorangeValid and i.sigId == 0:
observables['C1C'] = i.pseudorange
# Empirically it seems obvious ublox's std is
# actually a variation
observables_std['C1C'] = sqrt(i.pseudorangeStdev)*10
if i.gnssId == ConstellationId.GLONASS:
glonass_freq = i.glonassFrequencyIndex - 7
observables['D1C'] = -(constants.SPEED_OF_LIGHT / (constants.GLONASS_L1 + glonass_freq * constants.GLONASS_L1_DELTA)) * i.doppler
else: # GPS
glonass_freq = np.nan
observables['D1C'] = -(constants.SPEED_OF_LIGHT / constants.GPS_L1) * i.doppler
observables_std['D1C'] = (constants.SPEED_OF_LIGHT / constants.GPS_L1) * i.dopplerStdev
observables['S1C'] = i.cno
if i.trackingStatus.carrierPhaseValid:
observables['L1C'] = i.carrierCycles
else:
observables['L1C'] = np.nan
measurements.append(GNSSMeasurement(ConstellationId(i.gnssId), i.svId, recv_week, recv_tow,
observables, observables_std, glonass_freq))
return measurements
def read_rinex_obs(obsdata) -> List[List[GNSSMeasurement]]:
measurements: List[List[GNSSMeasurement]] = []
obsdata_keys = list(obsdata.data.keys())
first_sat = obsdata_keys[0]
n = len(obsdata.data[first_sat]['Epochs'])
for i in range(n):
recv_time_datetime = obsdata.data[first_sat]['Epochs'][i]
recv_time_datetime = recv_time_datetime.astype(datetime.datetime)
recv_time = GPSTime.from_datetime(recv_time_datetime)
measurements.append([])
for sat_str in obsdata_keys:
if np.isnan(obsdata.data[sat_str]['C1'][i]):
continue
observables, observables_std = {}, {}
for obs in obsdata.data[sat_str]:
if obs == 'Epochs':
continue
rinex3_obs_key = rinex3_obs_from_rinex2_obs(obs)
observables[rinex3_obs_key] = obsdata.data[sat_str][obs][i]
observables_std[rinex3_obs_key] = 1.
constellation_id, sv_id = get_constellation_and_sv_id(int(sat_str))
measurements[-1].append(GNSSMeasurement(constellation_id, sv_id,
recv_time.week, recv_time.tow,
observables, observables_std))
return measurements
def get_Q(recv_pos, sat_positions):
local = LocalCoord.from_ecef(recv_pos)
sat_positions_rel = local.ecef2ned(sat_positions)
sat_distances = np.linalg.norm(sat_positions_rel, axis=1)
A = np.column_stack((sat_positions_rel[:,0]/sat_distances, # pylint: disable=unsubscriptable-object
sat_positions_rel[:,1]/sat_distances, # pylint: disable=unsubscriptable-object
sat_positions_rel[:,2]/sat_distances, # pylint: disable=unsubscriptable-object
-np.ones(len(sat_distances))))
if A.shape[0] < 4 or np.linalg.matrix_rank(A) < 4:
return np.inf*np.ones((4,4))
Q = np.linalg.inv(A.T.dot(A))
return Q
def get_DOP(recv_pos, sat_positions):
Q = get_Q(recv_pos, sat_positions)
return np.sqrt(np.trace(Q))
def get_HDOP(recv_pos, sat_positions):
Q = get_Q(recv_pos, sat_positions)
return np.sqrt(np.trace(Q[:2,:2]))
def get_VDOP(recv_pos, sat_positions):
Q = get_Q(recv_pos, sat_positions)
return np.sqrt(Q[2,2])
def get_TDOP(recv_pos, sat_positions):
Q = get_Q(recv_pos, sat_positions)
return np.sqrt(Q[3,3])
def get_PDOP(recv_pos, sat_positions):
Q = get_Q(recv_pos, sat_positions)
return np.sqrt(np.trace(Q[:3,:3]))