Exemple #1
0
 def __init__(self, gps_week, time_of_week):
     # time of week in seconds, including fractions of a second
     self.time_of_week = time_of_week
     self.gps_week     = gps_week
     self.gps_time     = util.gpsTimeToTime(gps_week, time_of_week)
     self.prMeasured   = {}
     self.cpMeasured   = {}
     self.quality      = {}
     self.lli	  = {}
Exemple #2
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 def __init__(self, gps_week, time_of_week):
     # time of week in seconds, including fractions of a second
     self.time_of_week = time_of_week
     self.gps_week     = gps_week
     self.gps_time     = util.gpsTimeToTime(gps_week, time_of_week)
     self.prMeasured   = {}
     self.cpMeasured   = {}
     self.quality      = {}
     self.lli	  = {}
     self.cno          = {}
Exemple #3
0
    def RTCMType3_step(self, throttle=True):
        gpssec = util.gpsTimeToTime(self.gps_week, self.time_of_week)
        if gpssec < self.last_type3_time + self.type3_send_time and throttle:
            return ''

        self.last_type3_time = gpssec

        self.reset()

        rtcmzcount = self.modZCount()

        self.addbits(8, 0x66)  # header id
        self.addbits(6, 3)     # msg type 1
        self.addbits(10, 2)    # station id

        #  1st word should be sent here
        self.addbits(13, rtcmzcount) # z-count
        self.addbits(3, self.rtcmseq) # seq no.
        self.rtcmseq = (self.rtcmseq + 1) % 8

        self.addbits(5, 4) # word length
        self.addbits(3, 0) # health bits

        pos = self.pos

        X = int(pos.X * 100.0)
        Y = int(pos.Y * 100.0)
        Z = int(pos.Z * 100.0)

        self.addbits(8, (X>>24)&0xFF)
        self.addbits(8, (X>>16)&0xFF)
        self.addbits(8, (X>> 8)&0xFF)
        self.addbits(8, (X>> 0)&0xFF)

        self.addbits(8, (Y>>24)&0xFF)
        self.addbits(8, (Y>>16)&0xFF)
        self.addbits(8, (Y>> 8)&0xFF)
        self.addbits(8, (Y>> 0)&0xFF)

        self.addbits(8, (Z>>24)&0xFF)
        self.addbits(8, (Z>>16)&0xFF)
        self.addbits(8, (Z>> 8)&0xFF)
        self.addbits(8, (Z>> 0)&0xFF)

        while self.rtcbits != 0:
            self.addbits(8, 0xAA) # pad unused bits with 0xAA
        return self.buf + "\n\r"
Exemple #4
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    def RTCMType3_step(self, throttle=True):
        gpssec = util.gpsTimeToTime(self.gps_week, self.time_of_week)
        if gpssec < self.last_type3_time + self.type3_send_time and throttle:
            return ''

        self.last_type3_time = gpssec

        self.reset()

        rtcmzcount = self.modZCount()

        self.addbits(8, 0x66)  # header id
        self.addbits(6, 3)     # msg type 1
        self.addbits(10, 2)    # station id

        #  1st word should be sent here
        self.addbits(13, rtcmzcount) # z-count
        self.addbits(3, self.rtcmseq) # seq no.
        self.rtcmseq = (self.rtcmseq + 1) % 8

        self.addbits(5, 4) # word length
        self.addbits(3, 0) # health bits

        pos = self.pos

        X = int(pos.X * 100.0)
        Y = int(pos.Y * 100.0)
        Z = int(pos.Z * 100.0)

        self.addbits(8, (X>>24)&0xFF)
        self.addbits(8, (X>>16)&0xFF)
        self.addbits(8, (X>> 8)&0xFF)
        self.addbits(8, (X>> 0)&0xFF)

        self.addbits(8, (Y>>24)&0xFF)
        self.addbits(8, (Y>>16)&0xFF)
        self.addbits(8, (Y>> 8)&0xFF)
        self.addbits(8, (Y>> 0)&0xFF)

        self.addbits(8, (Z>>24)&0xFF)
        self.addbits(8, (Z>>16)&0xFF)
        self.addbits(8, (Z>> 8)&0xFF)
        self.addbits(8, (Z>> 0)&0xFF)

        while self.rtcbits != 0:
            self.addbits(8, 0xAA) # pad unused bits with 0xAA
        return self.buf + "\n\r"
Exemple #5
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        if (msg is None):
            continue
            #pass#break
        else:
            print('#', msg)
            if ((msg.name() == 'TIM_TM2')):  #&(msg.flags == 241)):
                #print('Got TM2 message')
                try:
                    msg.unpack()
                    timestring = '$HIT,'
                    timestring += str(msg.count)
                    timestring += ','
                    timestring += str(datetime.datetime.utcnow())
                    timestring += ','
                    filename = util.gpsTimeToTime(
                        msg.wnR, 1.0e-3 * msg.towMsR + 1.0e-9 * msg.towSubMsR)
                    timestring += str(filename)
                    timestring += ','
                    timestring += str(
                        datetime.datetime.utcfromtimestamp(filename))
                    print(timestring)
                    sys.stdout.flush()
                    ''' Micsig
					time.sleep(2)
					osc.write("MENU:STOP")
					print('#stop')
					sys.stdout.flush()
					time.sleep(1)
					print('#capture')
					sys.stdout.flush()
					osc.write(':STORage:CAPTure')
Exemple #6
0
    def RTCMType1_step(self, throttle=True):
        gpssec = util.gpsTimeToTime(self.gps_week, self.time_of_week)
        if gpssec < self.last_type1_time + self.type1_send_time and throttle:
            return ''

        self.last_type1_time = gpssec
        self.reset()

        tow = self.time_of_week
        deltat = tow - self.last_time_of_week

        errors = {}
        rates = {}
        for svid in self.error_history:
            #errors[svid] = sum(self.error_history[svid])/float(len(self.error_history[svid]))

            l = len(self.error_history[svid])
            # Extract the median half of the error array and take the average over that.  This
            # will reject outliers that we see pretty often, though most of those outliers only
            # last for 1 or 2 samples at a time so we might want to broaden this window.
            trim = sorted(self.error_history[svid])[l // 4: 3 * l // 4 + 1]
            errors[svid] = sum(trim) / float(len(trim))

            if svid in self.last_errors and deltat > 0:
                rates[svid] = (errors[svid] - self.last_errors[svid]) / deltat
            else:
                rates[svid] = 0
            
        msgsatid     = []
        msgprc       = []
        msgprrc      = []
        msgiode      = []
        msgudre      = []
        scalefactors = []
        for svid in self.error_history:
            if not svid in self.iode or not svid in errors:
                continue

            prc  = int(round(errors[svid]/0.02))
            prrc = int(round(rates[svid]/0.002))

            sf = 0
            while prc > 32767 or prc < -32768:
                sf += 1
                prc  = (prc + 8)  // 16
            if sf > 1:
                # skip satellites if we can't represent the error in the
                # number of bits allowed
                continue
            if sf == 1:
                prrc = (prrc + 8) // 16
            prrc = min(prrc, 127)
            prrc = max(prrc, -128)
            msgsatid.append(svid)
            msgprc.append(prc)
            msgprrc.append(prrc)
            msgiode.append(self.iode[svid])
            scalefactors.append(sf)

        msgsatcnt = len(msgsatid)
        if msgsatcnt == 0:
            return ''

        # clear the history
        self.last_errors = errors.copy()
        if self.history_length == 0:
            self.error_history = {}
        else:
            for svid in self.error_history:
                while len(self.error_history[svid]) > self.history_length:
                    self.error_history[svid].pop(0)
        self.last_time_of_week = tow

        rtcmzcount = self.modZCount()

        # first part of header
        self.addbits(8, 0x66)  # header id
        self.addbits(6, 1)     # msg type 1
        self.addbits(10, self.stationID) 

        #  second part of header
        self.addbits(13, rtcmzcount) # z-count
        self.addbits(3, self.rtcmseq) # seq no.
        self.rtcmseq = (self.rtcmseq + 1) % 8

        # now compute the word length of the message
        # each word contains 24 bits of data, plus 6 bits of parity
        bitlength = msgsatcnt * 40
        wordlength = bitlength // 24
        if (bitlength % 24) != 0:
            wordlength += 1

        self.addbits(5, wordlength)
        # health bits - mark as healthy
        self.addbits(3, 0)

        for i in range(msgsatcnt):
            self.addbits(1, scalefactors[i])
            self.addbits(2, 0)  # UDRE
            self.addbits(5, msgsatid[i]) # sat id no
            # we split the prc into two 8-bit bytes, because an RTCM word
            # boundary can occur here
            self.addbits(8, msgprc[i] >> 8) # prc hob
            self.addbits(8, msgprc[i] & 0xff) # prc lob
            self.addbits(8, msgprrc[i]) # prcc
            self.addbits(8, msgiode[i]) # IODE

        while self.rtcbits != 0:
            self.addbits(8, 0xAA) # pad unused bits with 0xAA
        print("MSG: bitlength=%u wordlength=%u len=%u" % (bitlength, wordlength, len(self.buf)))
        return self.buf + "\r\n"
def positionEstimate(satinfo):
    '''process raw messages to calculate position
    '''

    raw = satinfo.raw
    satinfo.reset()

    for svid in raw.prMeasured:

        if not satinfo.valid(svid):
            # we don't have ephemeris data for this space vehicle
            #print("not valid")
            continue

        # get the ephemeris and pseudo-range for this space vehicle
        ephemeris = satinfo.ephemeris[svid]
        prMes = raw.prMeasured[svid]
        prSmooth = satinfo.smooth.prSmoothed[svid]

        # calculate the time of flight for this pseudo range
        tof = prSmooth / util.speedOfLight

        # assume the time_of_week is the exact receiver time of week that the message arrived.
        # subtract the time of flight to get the satellite transmit time
        transmitTime = raw.time_of_week - tof

        timesec = util.gpsTimeToTime(raw.gps_week, raw.time_of_week)

        # calculate the satellite position at the transmitTime
        satPosition.satPosition(satinfo, svid, transmitTime)
        Trel = satinfo.satpos[svid].extra

        # correct for earths rotation in the time it took the messages to get to the receiver
        satPosition.correctPosition(satinfo, svid, tof)

        # calculate satellite azimuth and elevation
        satPosition.calculateAzimuthElevation(satinfo, svid, satinfo.lastpos)

        # calculate the satellite clock correction
        sat_clock_error = rangeCorrection.sv_clock_correction(satinfo, svid, transmitTime, Trel)

        # calculate the satellite group delay
        sat_group_delay = -satinfo.ephemeris[svid].Tgd

        # calculate the ionospheric range correction
        ion_corr = rangeCorrection.ionospheric_correction(satinfo, svid, transmitTime, satinfo.lastpos)

        # calculate the tropospheric range correction
        tropo_corr = rangeCorrection.tropospheric_correction_sass(satinfo, svid, satinfo.lastpos)

        # get total range correction
        total_range_correction = ion_corr + tropo_corr

        # correct the pseudo-range for the clock and atmospheric errors
        prCorrected = prSmooth + (sat_clock_error + sat_group_delay)*util.speedOfLight - total_range_correction

        # save the values in the satinfo object
        satinfo.prMeasured[svid] = prMes
        satinfo.prSmoothed[svid] = prSmooth
        satinfo.prCorrected[svid] = prCorrected
        satinfo.ionospheric_correction[svid] = ion_corr
        satinfo.tropospheric_correction[svid] = tropo_corr
        satinfo.satellite_clock_error[svid] = sat_clock_error
        satinfo.satellite_group_delay[svid] = sat_group_delay

    # if we got at least 4 satellites then calculate a position
    if len(satinfo.satpos) < 4:
        return None

    posestimate = positionLeastSquares(satinfo)

    satinfo.position_sum += posestimate
    satinfo.position_count += 1
    satinfo.average_position = satinfo.position_sum / satinfo.position_count
    satinfo.position_estimate = posestimate

    for svid in satinfo.prCorrected:
        if satinfo.reference_position is not None:
            satinfo.geometricRange[svid] = satinfo.reference_position.distance(satinfo.satpos[svid])
        elif satinfo.receiver_position is not None:
            satinfo.geometricRange[svid] = satinfo.receiver_position.distance(satinfo.satpos[svid])
        else:
            satinfo.geometricRange[svid] = satinfo.average_position.distance(satinfo.satpos[svid])

    return posestimate
def calculatePrCorrections(satinfo):
    raw = satinfo.raw
    satinfo.reset()
    errset = {}
    for svid in raw.prMeasured:

        if not satinfo.valid(svid):
            # we don't have ephemeris data for this space vehicle
            #print("not valid")
            continue

        # get the ephemeris and pseudo-range for this space vehicle
        ephemeris = satinfo.ephemeris[svid]
        prMes = raw.prMeasured[svid]
        prSmooth = satinfo.smooth.prSmoothed[svid]

        # calculate the time of flight for this pseudo range
        tof = prSmooth / util.speedOfLight

        # assume the time_of_week is the exact receiver time of week that the message arrived.
        # subtract the time of flight to get the satellite transmit time
        transmitTime = raw.time_of_week - tof

        timesec = util.gpsTimeToTime(raw.gps_week, raw.time_of_week)

        # calculate the satellite position at the transmitTime
        satPosition.satPosition(satinfo, svid, transmitTime)
        Trel = satinfo.satpos[svid].extra

        # correct for earths rotation in the time it took the messages to get to the receiver
        satPosition.correctPosition(satinfo, svid, tof)

        # calculate satellite azimuth and elevation
        satPosition.calculateAzimuthElevation(satinfo, svid, satinfo.lastpos)

        # calculate the satellite clock correction
        sat_clock_error = rangeCorrection.sv_clock_correction(
            satinfo, svid, transmitTime, Trel)

        # calculate the satellite group delay
        sat_group_delay = -satinfo.ephemeris[svid].Tgd

        # calculate the ionospheric range correction
        ion_corr = rangeCorrection.ionospheric_correction(
            satinfo, svid, transmitTime, satinfo.lastpos)

        # calculate the tropospheric range correction
        tropo_corr = rangeCorrection.tropospheric_correction_sass(
            satinfo, svid, satinfo.lastpos)

        # get total range correction
        total_range_correction = ion_corr + tropo_corr
        errset[svid] = -total_range_correction
        # correct the pseudo-range for the clock and atmospheric errors
        prCorrected = prSmooth + (
            sat_clock_error +
            sat_group_delay) * util.speedOfLight - total_range_correction

        # save the values in the satinfo object
        satinfo.prMeasured[svid] = prMes
        satinfo.prSmoothed[svid] = prSmooth
        satinfo.prCorrected[svid] = prCorrected
        satinfo.ionospheric_correction[svid] = ion_corr
        satinfo.tropospheric_correction[svid] = tropo_corr
        satinfo.satellite_clock_error[svid] = sat_clock_error
        satinfo.satellite_group_delay[svid] = sat_group_delay

    save_satlog(raw.time_of_week, errset)
Exemple #9
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	# Read GPS messages, if any
	while True:
		msg = dev.receive_message()
		if (msg is None):
			pass#break
		else:
			if msg.name() == 'TIM_TM2':
				#print('Got TM2 message')
				try:
					msg.unpack()
					timestring = '$HIT,'
					timestring += str(msg.count)
					timestring += ','
					timestring += str(datetime.datetime.utcnow())
					timestring += ','
					timestring += str(datetime.datetime.utcfromtimestamp(util.gpsTimeToTime(msg.wnR, 1.0e-3*msg.towMsR)))
					print(timestring)
					sys.stdout.flush()

					osc.write("MENU:STOP")
					time.sleep(1)
					osc.write(':STORage:CAPTure')
					time.sleep(2)
					#osc.write(':STORage:SAVECH1,UDISK')
					#time.sleep(5)
					osc.write("MENU:RUN")
					#time.sleep(.1s)


				except ublox.UBloxError as e:
					print(e)
Exemple #10
0
    def RTCMType1_step(self, throttle=True):
        gpssec = util.gpsTimeToTime(self.gps_week, self.time_of_week)
        if gpssec < self.last_type1_time + self.type1_send_time and throttle:
            return ''

        self.last_type1_time = gpssec
        self.reset()

        tow = self.time_of_week
        deltat = tow - self.last_time_of_week

        errors = {}
        rates = {}
        for svid in self.error_history:
            errors[svid] = sum(self.error_history[svid])/float(len(self.error_history[svid]))
            if svid in self.last_errors and deltat > 0:
                rates[svid] = (errors[svid] - self.last_errors[svid]) / deltat
            else:
                rates[svid] = 0
            
        msgsatid     = []
        msgprc       = []
        msgprrc      = []
        msgiode      = []
        msgudre      = []
        scalefactors = []
        for svid in self.error_history:
            if not svid in self.iode:
                continue

            prc  = int(round(errors[svid]/0.02))
            prrc = int(round(rates[svid]/0.002))

            sf = 0
            while prc > 32767 or prc < -32768:
                sf += 1
                prc  = (prc + 8)  // 16
            if sf > 1:
                # skip satellites if we can't represent the error in the
                # number of bits allowed
                continue
            if sf == 1:
                prrc = (prrc + 8) // 16
            prrc = min(prrc, 127)
            prrc = max(prrc, -128)
            msgsatid.append(svid)
            msgprc.append(prc)
            msgprrc.append(prrc)
            msgiode.append(self.iode[svid])
            scalefactors.append(sf)

        msgsatcnt = len(msgsatid)
        if msgsatcnt == 0:
            return ''

        # clear the history
        self.last_errors = errors.copy()
        if self.history_length == 0:
            self.error_history = {}
        else:
            for svid in self.error_history:
                while len(self.error_history[svid]) > self.history_length:
                    self.error_history[svid].pop(0)
        self.last_time_of_week = tow

        rtcmzcount = self.modZCount()

        # first part of header
        self.addbits(8, 0x66)  # header id
        self.addbits(6, 1)     # msg type 1
        self.addbits(10, self.stationID) 

        #  second part of header
        self.addbits(13, rtcmzcount) # z-count
        self.addbits(3, self.rtcmseq) # seq no.
        self.rtcmseq = (self.rtcmseq + 1) % 8

        # now compute the word length of the message
        # each word contains 24 bits of data, plus 6 bits of parity
        bitlength = msgsatcnt * 40
        wordlength = bitlength // 24
        if (bitlength % 24) != 0:
            wordlength += 1

        self.addbits(5, wordlength)
        # health bits - mark as healthy
        self.addbits(3, 0)

        for i in range(msgsatcnt):
            self.addbits(1, scalefactors[i])
            self.addbits(2, 0)  # UDRE
            self.addbits(5, msgsatid[i]) # sat id no
            # we split the prc into two 8-bit bytes, because an RTCM word
            # boundary can occur here
            self.addbits(8, msgprc[i] >> 8) # prc hob
            self.addbits(8, msgprc[i] & 0xff) # prc lob
            self.addbits(8, msgprrc[i]) # prcc
            self.addbits(8, msgiode[i]) # IODE

        while self.rtcbits != 0:
            self.addbits(8, 0xAA) # pad unused bits with 0xAA
        #print("MSG: bitlength=%u wordlength=%u len=%u" % (bitlength, wordlength, len(self.buf)))
        return self.buf + "\r\n"
Exemple #11
0
     sys.stdout.write('.')
     sys.stdout.flush()
 if msg.name() == 'TIM_TM2':
     try:
         msg.unpack()
         if (count_initialized == 0):
             count_start = msg.count - 1
             last_count = msg.count
             first_towMsR = msg.towMsR
             count_initialized = 1
             #print('First counter value: ' + str(count_start))
         if (msg.count < count_start):
             count_base += 65535
         #timestring = datetime.datetime.strftime("%d %b %Y %H:%M:%S.%f", datetime.datetime.utcfromtimestamp(util.gpsTimeToTime(msg.wnR, 1.0e-3*msg.towMsR)))
         tm2_time = datetime.datetime.utcfromtimestamp(
             util.gpsTimeToTime(msg.wnR, 1.0e-3 * msg.towMsR))
         #txt = "Counter = %5d Zero = %5d Diff = %5d %s\n" % (msg.count-count_start, count_start, msg.count-last_count, timestring)
         tm2_delta = tm2_time - pcnow
         txt = "TM2 %26s PC %26s delta(TM2-PC) %9.6f" % (
             tm2_time, str(pcnow), float(tm2_delta.total_seconds()))
         print txt
         last_count = msg.count
     except ublox.UBloxError as e:
         print(e)
 if msg.name() == 'NAV_TIMEUTC':
     try:
         #print(str(msg))
         msg.unpack()
         #print "GPS %04d-%02d-%02d %02d:%02d:%02d.%09d" % (msg.year, msg.month, msg.day, msg.hour, msg.min, msg.sec, msg.nano)
         gpstime = datetime.datetime(
             msg.year, msg.month, msg.day, msg.hour, msg.min,
Exemple #12
0
 else:
     if (msg.count > last_count):
         timestring = '$HIT,'
         # Edges since first count
         timestring += str(msg.count - first_count)
         timestring += ','
         # Edges in this run
         timestring += str(msg.count - last_count)
         timestring += ','
         # Computer time
         timestring += str(datetime.datetime.utcnow())
         timestring += ','
         # This provides the rising edge time to microsecond precision
         timestring += str(
             util.gpsTimeToTime(
                 msg.wnR,
                 1.0e-3 * msg.towMsR + 1.0e-9 * msg.towSubMsR))
         timestring += ','
         timestring += str(
             datetime.datetime.utcfromtimestamp(
                 util.gpsTimeToTime(
                     msg.wnR,
                     1.0e-3 * msg.towMsR + 1.0e-9 * msg.towSubMsR)))
         #timestring += str(datetime.datetime.utcfromtimestamp(util.gpsTimeToTime(msg.wnR, 1.0e6*(msg.towMsR % 1000 + msg.SubMsR)))
         timestring += ','
         # Tow sub millisecond fraction, in nanoseconds
         timestring += str(msg.towMsR)
         timestring += ','
         # Tow sub millisecond fraction, in nanoseconds
         timestring += str(msg.towSubMsR)
         print(timestring)
Exemple #13
0
def calculatePrCorrections(satinfo):
    raw = satinfo.raw
    satinfo.reset()
    errset={}
    for svid in raw.prMeasured:

        if not satinfo.valid(svid):
            # we don't have ephemeris data for this space vehicle
            #print("not valid")
            continue

        # get the ephemeris and pseudo-range for this space vehicle
        ephemeris = satinfo.ephemeris[svid]
        prMes = raw.prMeasured[svid]
        prSmooth = satinfo.smooth.prSmoothed[svid]

        # calculate the time of flight for this pseudo range
        tof = prSmooth / util.speedOfLight

        # assume the time_of_week is the exact receiver time of week that the message arrived.
        # subtract the time of flight to get the satellite transmit time
        transmitTime = raw.time_of_week - tof

        timesec = util.gpsTimeToTime(raw.gps_week, raw.time_of_week)

        # calculate the satellite position at the transmitTime
        satPosition.satPosition(satinfo, svid, transmitTime)
        Trel = satinfo.satpos[svid].extra

        # correct for earths rotation in the time it took the messages to get to the receiver
        satPosition.correctPosition(satinfo, svid, tof)

        # calculate satellite azimuth and elevation
        satPosition.calculateAzimuthElevation(satinfo, svid, satinfo.lastpos)

        # calculate the satellite clock correction
        sat_clock_error = rangeCorrection.sv_clock_correction(satinfo, svid, transmitTime, Trel)

        # calculate the satellite group delay
        sat_group_delay = -satinfo.ephemeris[svid].Tgd

        # calculate the ionospheric range correction
        ion_corr = rangeCorrection.ionospheric_correction(satinfo, svid, transmitTime, satinfo.lastpos)

        # calculate the tropospheric range correction
        tropo_corr = rangeCorrection.tropospheric_correction_sass(satinfo, svid, satinfo.lastpos)

        # get total range correction
        total_range_correction = ion_corr + tropo_corr
        errset[svid]=-total_range_correction
        # correct the pseudo-range for the clock and atmospheric errors
        prCorrected = prSmooth + (sat_clock_error + sat_group_delay)*util.speedOfLight - total_range_correction

        # save the values in the satinfo object
        satinfo.prMeasured[svid] = prMes
        satinfo.prSmoothed[svid] = prSmooth
        satinfo.prCorrected[svid] = prCorrected
        satinfo.ionospheric_correction[svid] = ion_corr
        satinfo.tropospheric_correction[svid] = tropo_corr
        satinfo.satellite_clock_error[svid] = sat_clock_error
        satinfo.satellite_group_delay[svid] = sat_group_delay

    save_satlog(raw.time_of_week, errset)