예제 #1
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    def getAudio(self):
        '''Get the audio from data

        Returns:
            :obj:`commSignal`: An audio signal
        '''

        audioFreq = self.__audioFreq
        strictness = self.__strictness
        #print(audioFreq, self.__bw)

        audioOut = comm.commSignal(audioFreq)
        bhFilter = filters.blackmanHarris(151)
        fmDemdulator = demod_fm.demod_fm()
        chunkerObj = chunker.chunker(sigsrc)
        #print(chunkerObj.getChunks)
        #print(len(chunkerObj.getChunks[:10]))

        for i in chunkerObj.getChunks:
            offset = self.__offset

            sig = comm.commSignal(self.__sigsrc.sampFreq, self.__sigsrc.read(*i), chunkerObj)\
                .offsetFreq(self.__offset).filter(bhFilter)\
                .bwLim(self.__bw, uniq="First")\
                .funcApply(fmDemdulator.demod)\
                .bwLim(audioFreq, strictness)

            audioOut.extend(sig)

        return audioOut
예제 #2
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    def __getAM(self, sig):
        '''Do AM demodulation in chunks of given signal

        Args:
            sig (:obj:`comm object`): Input signal

        Returns:
            :obj:`commSignal`: AM demodulated signal
        '''

        logging.info('Beginning AM demodulation in chunks')

        amDemdulator = demod_am.demod_am()
        amOut = comm.commSignal(sig.sampRate)

        chunkerObj = chunker.chunker(sig, chunkSize=60000 * 4)

        for i in chunkerObj.getChunks:

            logging.info('Processing chunk %d of %d chunks',
                         chunkerObj.getChunks.index(i) + 1,
                         len(chunkerObj.getChunks))
            demodSig = amDemdulator.demod(sig.signal[i[0]:i[1]])
            amOut.extend(comm.commSignal(sig.sampRate, demodSig))

        logging.info('AM demodulation completed')

        return amOut
예제 #3
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    def __audio(self, audioFreq=constants.NOAA_AUDSAMPRATE, strictness=True):
        '''Get the audio from data at this sampling rate

        Args:
            audioFreq (:obj:`int`, optional): Target frequency of sampling of audio
            strictness (:obj:`bool`, optional): Strictness of sampling

        Returns:
            :obj:`commSignal`: An audio signal
        '''

        logging.info('Beginning FM demodulation to get audio in chunks')

        audioOut = comm.commSignal(audioFreq)
        bhFilter = filters.blackmanHarris(151)
        fmDemdulator = demod_fm.demod_fm()
        chunkerObj = chunker.chunker(self.__sigsrc)

        for i in chunkerObj.getChunks:

            logging.info('Processing chunk %d of %d chunks',
                         chunkerObj.getChunks.index(i) + 1,
                         len(chunkerObj.getChunks))

            sig = comm.commSignal(
                self.__sigsrc.sampFreq, self.__sigsrc.read(*i),
                chunkerObj).offsetFreq(self.__offset).filter(bhFilter).bwLim(
                    self.__bw, uniq="First").funcApply(
                        fmDemdulator.demod).bwLim(audioFreq, strictness)
            audioOut.extend(sig)

        logging.info('FM demodulation successfully complete')
        self.__audOut = audioOut

        return audioOut
예제 #4
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nb_dir = os.path.split(os.getcwd())[0]
if nb_dir not in sys.path:
    sys.path.append(nb_dir)

from directdemod import source, sink, chunker, comm, constants, filters, demod_am, demod_fm
import matplotlib.pyplot as plt

## First the source of data
fileName = "../samples/SDRSharp_20170830_073907Z_145825000Hz_IQ_autogain.wav"
sigsrc = source.IQwav(fileName)

# initialize all objects out of loop
sigOut = comm.commSignal(sigsrc.sampFreq)
bhFilter = filters.blackmanHarris(151)
fmDemdulator = demod_fm.demod_fm()
chunkerObj = chunker.chunker(sigsrc)

# use this for loop
for i in chunkerObj.getChunks:

    # everything same as previous, but remember to use the same objects, then the continuity will be maintained between the chunks

    sig = comm.commSignal(sigsrc.sampFreq, sigsrc.read(*i), chunkerObj)
    sig.filter(bhFilter)
    sig.bwLim(30000)
    sig.funcApply(fmDemdulator.demod)
    sigOut.extend(sig)

## plot the signal
plt.plot(sigOut.signal)
plt.show()
예제 #5
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    def getSyncs(self):

        '''Get syncs of Funcube

        Returns:
            :obj:`list`: list of detected syncs
        '''

        # create chunker object
        chunkerObj = chunker.chunker(self.__sigsrc)

        # butter filter
        bf = filters.butter(self.__sigsrc.sampFreq, self.__bw)

        # init vars for gardner
        symbolPeriod = self.__sigsrc.sampFreq/12000
        timing = 0.00
        gardnerC, gardnerB, gardnerA = 0.00, 0.00, 0.00
        agcObj = agc()
        pllObj = costas()
        ctr = 0

        sync = np.array([int(i) for i in "101000110001000000000001010111100"])

        sync12khz = np.repeat(sync, 10)

        sync[sync == 1] = 127
        sync[sync == 0] = -128
        sync2mhz = np.repeat(sync, int(2048000/1200))

        maxResBuff = []
        minResBuff = []
        maxBuffRetain = -1
        maxBuffStart = 0

        minSyncs = []
        maxSyncs = []

        numCtrs = int(chunkerObj.getChunks[-1][-1]*12000/2048000)
        start_time = time.time()
        lastMin = None
        ctrMain = 0


        doppCorrect_target = None
        doppCorrect_current = None

        chunk_number = 0

        for i in chunkerObj.getChunks[:]:
            #interpolate
            sig = comm.commSignal(self.__sigsrc.sampFreq, self.__sigsrc.read(*i))
            
            doppCorrect_freqs = self.__offset
            if self.__corrfreq:

                bandwidth = 20000 # the bandwidth must cover the signal to be able to find it.
                chunk_offset = frequency_shift.correct(self.__sigsrc.memmap, self.__sigsrc.sampFreq, self.__center_frequency, self.__signal_freq, bandwidth, chunk_number, len(chunkerObj.getChunks))

                logging.info("doppler shift is %f Hz",chunk_offset)

                chunk_number += 1

                doppCorrect_target = self.__offset + chunk_offset
                if doppCorrect_current == None:
                    doppCorrect_current = doppCorrect_target

                doppCorrect_bw = 2000.0/constants.PROC_CHUNKSIZE

                if doppCorrect_target > doppCorrect_current:
                    doppCorr_delta = doppCorrect_bw
                    doppCorrect_freqs = np.arange(doppCorrect_current, doppCorrect_current + ((i[1]-i[0]) * doppCorr_delta) + (10*doppCorr_delta), doppCorr_delta)[:len(sig.signal)]
                    doppCorrect_freqs[doppCorrect_freqs > doppCorrect_target] = doppCorrect_target
                else:
                    doppCorr_delta = -1*doppCorrect_bw
                    doppCorrect_freqs = np.arange(doppCorrect_current, doppCorrect_current + ((i[1]-i[0]) * doppCorr_delta) + (10*doppCorr_delta), doppCorr_delta)[:len(sig.signal)]
                    doppCorrect_freqs[doppCorrect_freqs < doppCorrect_target] = doppCorrect_target

                doppCorrect_current = doppCorrect_freqs[-1]

            sig.offsetFreq(doppCorrect_freqs)

            sig.filter(bf)

            ctrCurr = 0

            # main loop
            for i in sig.signal:

                ### MAXSYNC detection by correlation

                # start storing 2mhz values near sync possible regions
                if not lastMin is None and (ctr > lastMin + (4.9*12000) - (2*len(sync12khz)) or not maxBuffRetain == -1) and not ctr > lastMin + (5.2*12000):
                    if len(maxResBuff) == 0:
                        maxBuffStart = ctrMain
                    maxResBuff.append(lim(np.real(i*pllObj.output)/2))

                # see if correlation is to be performed
                if maxBuffRetain == -1:
                    if len(maxResBuff) > (2 * len(sync2mhz)):
                        maxBuffStart += 1
                        maxResBuff.pop(0)
                elif maxBuffRetain == 0:
                    maxBuffRetain -= 1
                    corr = np.abs(np.correlate(maxResBuff,sync2mhz, mode='same'))
                    logging.info("MAXSYNC %d", maxBuffStart+np.argmax(corr))
                    #print("MAXSYNC", maxBuffStart, np.argmax(corr), maxBuffStart+np.argmax(corr))
                    maxSyncs.append(maxBuffStart+np.argmax(corr))
                    maxResBuff = []

                    #plt.plot(corr)
                    #plt.show()
                else:
                    maxBuffRetain -= 1

                # Gardners algorithm
                if timing >= symbolPeriod/2 and timing < ((symbolPeriod/2)+1):
                    gardnerB = agcObj.adjust(i)

                elif timing >= symbolPeriod:
                    gardnerA = agcObj.adjust(i)
                    timing -= symbolPeriod
                    resync_error = (np.imag(gardnerA) - np.imag(gardnerC)) * np.imag(gardnerB)
                    timing += (resync_error*symbolPeriod/(2000000.0))
                    gardnerC = gardnerA
                    gardnerA = pllObj.loop(gardnerA)
                    ctr += 1

                    # 12khz buffer
                    minResBuff.append(limBin(np.real(gardnerA)))
                    minResBuff = minResBuff[-1*len(sync12khz):]

                    # print periodic status
                    try:
                        if ctr%1000 == 0:
                            logging.info("[%.2f percent complete] [%.2f seconds elapsed] [%.2f seconds remain]", (ctr*100/numCtrs), (time.time() - start_time), (((time.time() - start_time)/(ctr/numCtrs))-(time.time() - start_time)))
                            #print(ctr, '[%.2f' %(ctr*100/numCtrs),"%]",'[%.2f' %(time.time() - start_time),"seconds elapsed]",'[%.2f' %(((time.time() - start_time)/(ctr/numCtrs))-(time.time() - start_time)), "seconds remaining]", pllObj.mean, doppCorrect_freqs[ctrCurr], doppCorrect_target)
                    except:
                        pass

                    # see if sync is present
                    if len(minResBuff) == len(sync12khz) and np.abs(np.sum(np.abs(np.array(minResBuff) - sync12khz)) - (len(sync12khz)/2)) > 120:
                        logging.info("MINSYNC: %d %f",ctr, np.abs(np.sum(np.abs(np.array(minResBuff) - sync12khz)) - (len(sync12khz)/2)))
                        #print("MINSYNC:",ctr, np.abs(np.sum(np.abs(np.array(minResBuff) - sync12khz)) - (len(sync12khz)/2)))
                        minSyncs.append(ctr)
                        lastMin = ctr
                        maxBuffRetain = 2 * len(sync2mhz)

                timing += 1
                ctrMain += 1
                ctrCurr += 1

        if len(maxSyncs) > 0:
            # check usefulness
            if np.min(np.abs(np.diff(maxSyncs) - (4.98*2048000))) < (0.2*2048000):
                self.__useful = 1
            return list(maxSyncs)[1:]
        else:
            return []
예제 #6
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    def getMsg(self):
        '''Get the message from data

        Returns:
            :string: A string of message data
        '''

        if self.__msg is None:

            sig = comm.commSignal(self.__sigsrc.sampFreq)

            chunkerObj = chunker.chunker(self.__sigsrc)
            bhFilter = filters.blackmanHarris(151)
            fmDemodObj = demod_fm.demod_fm()

            for i in chunkerObj.getChunks:

                logging.info('Processing chunk %d of %d chunks',
                             chunkerObj.getChunks.index(i) + 1,
                             len(chunkerObj.getChunks))

                # get the signal
                chunkSig = comm.commSignal(self.__sigsrc.sampFreq,
                                           self.__sigsrc.read(*i), chunkerObj)

                ## Offset the frequency if required, not needed here
                chunkSig.offsetFreq(self.__offset)

                ## Apply a blackman harris filter to get rid of noise
                chunkSig.filter(bhFilter)

                ## Limit bandwidth
                chunkSig.bwLim(self.__bw)

                # store signal
                sig.extend(chunkSig)

            ## FM demodulate
            sig.funcApply(fmDemodObj.demod)
            logging.info('FM demod complete')

            ## APRS has two freqs 1200 and 2200, hence create a butter band pass filter from 1200-500 to 2200+500
            sig.filter(
                filters.butter(sig.sampRate,
                               1200 - 500,
                               2200 + 500,
                               typeFlt=constants.FLT_BP))
            logging.info('Filtering complete')

            ## plot the signal
            if self.__graphs == 1:
                plt.plot(sig.signal)
                plt.show()

            buffer_size = int(np.round(self.__bw / self.__BAUDRATE))
            SAMPLE_PER_BAUD = self.__bw // self.__BAUDRATE

            # creating the “correlation list" for the comparison frequencies of the digital frequency filers
            corr_mark_i = np.zeros(buffer_size)
            corr_mark_q = np.zeros(buffer_size)
            corr_space_i = np.zeros(buffer_size)
            corr_space_q = np.zeros(buffer_size)

            # filling the "correlation list" with sampled waveform for the two frequencies.
            for i in range(buffer_size):
                mark_angle = (i * 1.0 / self.__bw) / (
                    1 / self.__mark_frequency) * 2 * np.pi
                corr_mark_i[i] = np.cos(mark_angle)
                corr_mark_q[i] = np.sin(mark_angle)

                space_angle = (i * 1.0 / self.__bw) / (
                    1 / self.__space_frequency) * 2 * np.pi
                corr_space_i[i] = np.cos(space_angle)
                corr_space_q[i] = np.sin(space_angle)

            # now we check the full signal for the binary states, whether it is closer to 1200 hz or closer to 2200 Hz
            binary_filter = np.zeros(len(sig.signal))

            for sample in range(len(sig.signal) - buffer_size):
                corr_mi = 0
                corr_mq = 0
                corr_si = 0
                corr_sq = 0

                for sub in range(buffer_size):
                    corr_mi = corr_mi + sig.signal[sample +
                                                   sub] * corr_mark_i[sub]
                    corr_mq = corr_mq + sig.signal[sample +
                                                   sub] * corr_mark_q[sub]

                    corr_si = corr_si + sig.signal[sample +
                                                   sub] * corr_space_i[sub]
                    corr_sq = corr_sq + sig.signal[sample +
                                                   sub] * corr_space_q[sub]

                binary_filter[sample] = (corr_mi**2 + corr_mq**2 - corr_si**2 -
                                         corr_sq**2)
            logging.info('Binary filter complete')
            if self.__graphs == 1:
                plt.plot(sig.signal / np.max(sig.signal))
                plt.plot(np.sign(binary_filter))
                plt.show()

            # now trying to find the raising or falling edges of the bits
            # generating the edge detection kernel
            kernel = np.zeros(SAMPLE_PER_BAUD)
            for i in range(len(kernel)):
                if i < SAMPLE_PER_BAUD // 2:
                    kernel[i] = -1
                else:
                    kernel[i] = 1

            changes = np.correlate(np.sign(binary_filter), kernel,
                                   mode="same") / SAMPLE_PER_BAUD

            if self.__graphs == 1:
                plt.plot(np.sign(binary_filter))
                plt.plot(changes)
                plt.title("bit starts")
                plt.show()

            # by using the edges of the bits for synching the sampling to the transmitted bits, the algo is
            # self synchronizing.
            # but sometimes the crossing areas between the bits can be uncertain. for that, a peak detection defines
            # only one solution in close vicinity and defining the edges further.
            peaks = peakdetect.peakdetect(np.abs(changes),
                                          lookahead=int(SAMPLE_PER_BAUD *
                                                        0.65))

            peaks1_x = []
            peaks1_y = []

            # positive peaks
            for i in range(len(peaks[0])):
                peaks1_x.append(peaks[0][i][0])
                peaks1_y.append(peaks[0][i][1])

            if self.__graphs == 1:
                plt.plot(peaks1_x, peaks1_y, "o")
                plt.plot(np.abs(changes))
                plt.plot(np.sign(binary_filter))
                plt.plot(sig.signal / np.max(sig.signal))
                plt.show()

            bit_repeated = np.round(
                np.diff(peaks1_x) / (self.__bw / self.__BAUDRATE))
            logging.info('Bit repeat complete')
            if self.__graphs == 1:
                plt.plot(np.sign(binary_filter))
                plt.plot(peaks1_x[:-1], bit_repeated, "*")
                plt.grid()
                plt.title("where frequency shifts")
                plt.show()

            # making the bits for nrzi
            bitstream_nrzi = []

            c = 0
            for i in range(len(bit_repeated)):
                # print(c, i, x1[i], "p", int(bit_repeated[i]))
                for repeats in range(int(bit_repeated[i])):
                    bitstream_nrzi.append((np.mean(
                        binary_filter[peaks1_x[i] +
                                      repeats * SAMPLE_PER_BAUD:peaks1_x[i] +
                                      (repeats + 1) * SAMPLE_PER_BAUD])))
                    # print(c, bitstream_nrzi[-1])
                    c += 1

            # here we convert the nrzi bits to normal bits
            bitstream = decode_afsk1200.decode_nrzi(np.sign(bitstream_nrzi))
            logging.info('Decoding NRZI complete')

            if self.__graphs == 1:
                plt.plot(np.sign(bitstream_nrzi))
                plt.plot(bitstream_nrzi, "o-")
                plt.plot(bitstream, "*")
                plt.show()

            bit_startflag = []
            bit_startflag_marker = []

            for bit in range(len(bitstream) - 8):
                out = ""
                for i in range(8):
                    out += str(bitstream[bit + i])

                if out == "01111110":
                    # print(bit)
                    bit_startflag.append(bit)
                    bit_startflag_marker.append(1)

            length = np.diff(bit_startflag)

            # there are still the stuffed bits inside the bit stream, so we need to find them...
            bitstream_stuffed = decode_afsk1200.find_bit_stuffing(bitstream)

            if self.__graphs == 1:
                plt.plot(bitstream_nrzi)
                plt.plot(bitstream, "o-")
                plt.plot(bit_startflag[:-1], length, "o")
                plt.plot(bit_startflag, bit_startflag_marker, "o")
                plt.plot(bitstream_stuffed, "*")
                plt.title("test1")
                plt.show()
            logging.info('Stuffed bit removal complete')
            # checking at each possible start flag, if the bit stream was received correctly.
            # this is done by checking the crc16 at the end of the msg with the msg body.
            for flag in range(len(bit_startflag) - 1):

                # and firstly, we need to get rid of the stuffed bits, that are still inside the bit stream
                bits = decode_afsk1200.reduce_stuffed_bit(
                    bitstream[bit_startflag[flag] + 8:bit_startflag[flag + 1]],
                    bitstream_stuffed[bit_startflag[flag] +
                                      8:bit_startflag[flag + 1]])

                msg = bits[:-16]

                if len(bits) % 8 == 0 and len(msg) > 16 * 8:

                    out = ""
                    for i in range(len(msg)):
                        out += str(msg[i])
                    crc = framechecksequence.fcs_crc16(out)

                    crc_received = ""
                    msg_rest = bits[-16:]
                    for i in range(len(msg_rest)):
                        crc_received += str(msg_rest[i])

                    if crc_received == crc:
                        msg_text = decode_afsk1200.bits_to_msg(msg)

                        print("one aprs msg with correct crc is found. #",
                              flag, "starts at", bit_startflag[flag],
                              "length is",
                              len(bits) / 8)
                        msg_text

                        if self.__graphs == 1:
                            plt.plot(
                                bitstream[bit_startflag[flag] +
                                          8:bit_startflag[flag + 1] + 8], "o-")
                            plt.plot(bits, "*-")
                            plt.show()

                        # there can be several messages per stream, so for now only the last is stored.
                        # to-do
                        self.__msg = "template: space rocks!"
                        self.__useful = 1

            logging.info('Message extraction complete')

        return self.__msg
예제 #7
0
    def getSyncs(self):
        '''Get syncs of Meteor M2

        Returns:
            :obj:`list`: list of detected syncs
        '''

        # create chunker object
        chunkerObj = chunker.chunker(self.__sigsrc)

        # butter filter
        bf = filters.butter(self.__sigsrc.sampFreq, self.__bw)

        # init vars for gardner
        symbolPeriod = self.__sigsrc.sampFreq / 72000
        timing = 0.00
        gardnerC, gardnerB, gardnerA = 0.00, 0.00, 0.00
        agcObj = agc()
        pllObj = costas()
        ctr = 0

        sync = [
            int(i) for i in
            "0, 13, 13, 12, 13, 13, 13, 0, 0, 0, 13, 13, 0, 13, 13, 0, 13, 0, 0, 0, 13, 13, 13, 0, 0, 13, 0, 13, 0, 13, 0, 13, 13, 0, 0, 0, 13, 13, 0, 0, 0, 0, 13, 0, 13, 13, 0, 0, 0, 0, 0, 13, 1, 13, 0, 13, 13, 13, 13, 12, 0, 13, 0, 13, 0, 0, 13, 0, 13, 0, 13, 13, 0, 13, 13, 13, 0, 0, 0, 0, 13, 0, 13, 0, 13, 13, 13, 13, 13, 0, 13, 13, 13, 0, 0, 0, 0, 13, 13, 13, 0, 13, 0, 0, 0, 13, 0, 13, 13, 0, 13, 0, 13, 13, 0, 0, 0, 13, 13, 13"
            .split(",")
        ]
        sync = np.array(sync)
        sync[sync < 7] = 0
        sync[sync >= 7] = 1

        sync72khz = np.repeat(sync, 1)

        sync72khz1 = []
        for i in range(len(sync72khz)):
            if i % 2 == 0:
                sync72khz1.append(sync72khz[i])
            else:
                sync72khz1.append(1 - sync72khz[i])
        sync72khz1 = np.array(sync72khz1)

        sync72khz2 = []
        for i in range(len(sync72khz)):
            if i % 2 == 1:
                sync72khz2.append(sync72khz[i])
            else:
                sync72khz2.append(1 - sync72khz[i])
        sync72khz2 = np.array(sync72khz2)

        sync[sync == 1] = 127
        sync[sync == 0] = -128
        sync2mhz = np.repeat(sync, int(2048000 / 72000))

        sync = np.array(sync72khz1[:])
        sync[sync == 1] = 127
        sync[sync == 0] = -128
        sync2mhz1 = np.repeat(sync, int(2048000 / 72000))

        sync = np.array(sync72khz2[:])
        sync[sync == 1] = 127
        sync[sync == 0] = -128
        sync2mhz2 = np.repeat(sync, int(2048000 / 72000))

        maxResBuff = []
        minResBuff1 = []
        minResBuff2 = []
        maxBuffRetain = -1
        maxBuffStart = 0

        minSyncs = []
        maxSyncs = []

        numCtrs = int(chunkerObj.getChunks[-1][-1] * 72000 / 2048000)
        start_time = time.time()
        lastMin = None
        ctrMain = 0

        sync2mhzChosen = sync2mhz

        for i in chunkerObj.getChunks[:]:

            #interpolate
            sig = comm.commSignal(self.__sigsrc.sampFreq,
                                  self.__sigsrc.read(*i))
            sig.offsetFreq(self.__offset)
            sig.filter(bf)

            # main loop
            for i in sig.signal:

                ### MAXSYNC detection by correlation

                # start storing 2mhz values near sync possible regions
                if not lastMin is None and (
                        ctr > lastMin + (0.1 * 72000) -
                    (2 * len(sync72khz)) or not maxBuffRetain
                        == -1) and not ctr > lastMin + (1 * 72000):
                    if len(maxResBuff) == 0:
                        maxBuffStart = ctrMain
                    corrVal = i * pllObj.output
                    maxResBuff.append(lim(np.real(corrVal) / 2))
                    maxResBuff.append(lim(np.imag(corrVal) / 2))

                # see if correlation is to be performed
                if maxBuffRetain == -1:
                    if len(maxResBuff) > (2 * len(sync2mhz)):
                        maxBuffStart += 1
                        maxResBuff.pop(0)
                        maxResBuff.pop(0)
                elif maxBuffRetain == 0:
                    maxBuffRetain -= 1
                    corr = np.abs(
                        np.correlate(maxResBuff, sync2mhzChosen, mode='same'))
                    logging.info("MAXSYNC %d",
                                 maxBuffStart + (np.argmax(corr) / 2.0))
                    #print("MAXSYNC", maxBuffStart, np.argmax(corr), maxBuffStart+np.argmax(corr))
                    maxSyncs.append(maxBuffStart + (np.argmax(corr) / 2.0))
                    maxResBuff = []

                    #plt.plot(corr)
                    #plt.show()
                else:
                    maxBuffRetain -= 1

                # Gardners algorithm
                if timing >= symbolPeriod / 2 and timing < (
                    (symbolPeriod / 2) + 1):
                    gardnerB = agcObj.adjust(i)

                elif timing >= symbolPeriod:
                    gardnerA = agcObj.adjust(i)
                    timing -= symbolPeriod
                    resync_error = (np.imag(gardnerA) -
                                    np.imag(gardnerC)) * np.imag(gardnerB)
                    timing += (resync_error * symbolPeriod / (2000000.0))
                    gardnerC = gardnerA
                    gardnerA = pllObj.loop(gardnerA)
                    ctr += 1

                    # print periodic status
                    try:
                        if ctr % 1000 == 0:
                            logging.info(
                                "[%.2f percent complete] [%.2f seconds elapsed] [%.2f seconds remain]",
                                (ctr * 100 / numCtrs),
                                (time.time() - start_time),
                                (((time.time() - start_time) /
                                  (ctr / numCtrs)) -
                                 (time.time() - start_time)))
                            #print(ctr, '[%.2f' %(ctr*100/numCtrs),"%]",'[%.2f' %(time.time() - start_time),"seconds elapsed]",'[%.2f' %(((time.time() - start_time)/(ctr/numCtrs))-(time.time() - start_time)), "seconds remaining]", pllObj.mean)
                    except:
                        pass

                    if lastMin is None or ctr > lastMin + 0.1 * (72000):
                        # 72khz buffer
                        minResBuff1.append(limBin(np.real(gardnerA)))
                        minResBuff1.append(limBin(np.imag(gardnerA)))
                        minResBuff1 = minResBuff1[-1 * len(sync72khz):]

                        minResBuff2.append(limBin(np.imag(gardnerA)))
                        minResBuff2.append(limBin(np.real(gardnerA)))
                        minResBuff2 = minResBuff2[-1 * len(sync72khz):]

                        buff1corr, buff2corr, buff3corr, buff4corr, buff5corr, buff6corr = 0, 0, 0, 0, 0, 0
                        if len(minResBuff1) == len(sync72khz):
                            buff1corr = np.abs(
                                np.sum(
                                    np.abs(np.array(minResBuff1) -
                                           sync72khz)) - (len(sync72khz) / 2))
                        #if len(minResBuff2) == len(sync72khz):
                        #    buff2corr = np.abs(np.sum(np.abs(np.array(minResBuff2) - sync72khz)) - (len(sync72khz)/2))

                        #if len(minResBuff1) == len(sync72khz1):
                        #    buff3corr = np.abs(np.sum(np.abs(np.array(minResBuff1) - sync72khz1)) - (len(sync72khz1)/2))
                        if len(minResBuff2) == len(sync72khz1):
                            buff4corr = np.abs(
                                np.sum(
                                    np.abs(np.array(minResBuff2) -
                                           sync72khz1)) -
                                (len(sync72khz1) / 2))

                        #if len(minResBuff1) == len(sync72khz2):
                        #    buff5corr = np.abs(np.sum(np.abs(np.array(minResBuff1) - sync72khz2)) - (len(sync72khz2)/2))
                        #if len(minResBuff2) == len(sync72khz2):
                        #    buff6corr = np.abs(np.sum(np.abs(np.array(minResBuff2) - sync72khz2)) - (len(sync72khz2)/2))

                        if buff1corr > 30 or buff2corr > 30:
                            sync2mhzChosen = sync2mhz
                        if buff3corr > 30 or buff4corr > 30:
                            sync2mhzChosen = sync2mhz1
                        if buff4corr > 30 or buff6corr > 30:
                            sync2mhzChosen = sync2mhz2

                        # see if sync is present
                        if buff1corr > 30 or buff2corr > 30 or buff3corr > 30 or buff4corr > 30 or buff5corr > 30 or buff6corr > 30:
                            logging.info("MINSYNC: %d", ctr)
                            #logging.info("MINSYNC: %d %f %f %f %f %f %f",ctr, buff1corr, buff2corr, buff3corr, buff4corr, buff5corr, buff6corr)
                            #print("MINSYNC:",ctr, np.abs(np.sum(np.abs(np.array(minResBuff) - sync72khz)) - (len(sync72khz)/2)))
                            minSyncs.append(ctr)
                            lastMin = ctr
                            maxBuffRetain = 2 * len(sync2mhz)

                timing += 1
                ctrMain += 1

        if len(maxSyncs) > 0:
            # check usefulness
            if np.min(np.abs(np.diff(maxSyncs) -
                             (0.11 * 2048000))) < (0.05 * 2048000):
                self.__useful = 1
            return list(maxSyncs)[1:]
        else:
            return []