def set_folding_params(self):
if (self.pulse_freq <= 0):
return
# Compute required sample rate
self.sample_rate = int(self.pulse_freq * self.folding)
# And the implied decimation rate
required_decimation = int(self.folder_input_rate / self.sample_rate)
# We also compute a new FFT comb filter, based on the expected
# spectral profile of our pulse parameters
#
# FFT-based comb filter
#
N_COMB_TAPS = int(self.sample_rate * 4)
if N_COMB_TAPS > 2000:
N_COMB_TAPS = 2000
self.folder_comb_taps = Numeric.zeros(N_COMB_TAPS, Numeric.Complex64)
fincr = (self.sample_rate) / float(N_COMB_TAPS)
for i in range(0, len(self.folder_comb_taps)):
self.folder_comb_taps[i] = complex(0.0, 0.0)
freq = 0.0
harmonics = [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0]
for i in range(0, len(self.folder_comb_taps) / 2):
for j in range(0, len(harmonics)):
if abs(freq - harmonics[j] * self.pulse_freq) <= fincr:
self.folder_comb_taps[i] = complex(4.0, 0.0)
if harmonics[j] == 1.0:
self.folder_comb_taps[i] = complex(8.0, 0.0)
freq += fincr
if self.enable_comb_filter == True:
# Set the just-computed FFT comb filter taps
self.folder_comb.set_taps(self.folder_comb_taps)
# And compute a new decimated bandpass filter, to go in front
# of the comb. Primary function is to decimate and filter down
# to an exact-ish multiple of the target pulse rate
#
self.folding_taps = gr.firdes_band_pass(1.0, self.folder_input_rate,
0.10, self.sample_rate / 2, 10,
gr.firdes.WIN_HAMMING)
# Set the computed taps for the bandpass/decimate filter
self.folder_bandpass.set_taps(self.folding_taps)
def set_folding_params(self):
if (self.pulse_freq <= 0):
return
# Compute required sample rate
self.sample_rate = int(self.pulse_freq*self.folding)
# And the implied decimation rate
required_decimation = int(self.folder_input_rate / self.sample_rate)
# We also compute a new FFT comb filter, based on the expected
# spectral profile of our pulse parameters
#
# FFT-based comb filter
#
N_COMB_TAPS=int(self.sample_rate*4)
if N_COMB_TAPS > 2000:
N_COMB_TAPS = 2000
self.folder_comb_taps = Numeric.zeros(N_COMB_TAPS,Numeric.Complex64)
fincr = (self.sample_rate)/float(N_COMB_TAPS)
for i in range(0,len(self.folder_comb_taps)):
self.folder_comb_taps[i] = complex(0.0, 0.0)
freq = 0.0
harmonics = [1.0,2.0,3.0,4.0,5.0,6.0,7.0]
for i in range(0,len(self.folder_comb_taps)/2):
for j in range(0,len(harmonics)):
if abs(freq - harmonics[j]*self.pulse_freq) <= fincr:
self.folder_comb_taps[i] = complex(4.0, 0.0)
if harmonics[j] == 1.0:
self.folder_comb_taps[i] = complex(8.0, 0.0)
freq += fincr
if self.enable_comb_filter == True:
# Set the just-computed FFT comb filter taps
self.folder_comb.set_taps(self.folder_comb_taps)
# And compute a new decimated bandpass filter, to go in front
# of the comb. Primary function is to decimate and filter down
# to an exact-ish multiple of the target pulse rate
#
self.folding_taps = gr.firdes_band_pass (1.0, self.folder_input_rate,
0.10, self.sample_rate/2, 10,
gr.firdes.WIN_HAMMING)
# Set the computed taps for the bandpass/decimate filter
self.folder_bandpass.set_taps (self.folding_taps)
def __init__(self, frame, panel, vbox, argv):
stdgui2.std_top_block.__init__(self, frame, panel, vbox, argv)
self.frame = frame
self.panel = panel
parser = OptionParser(option_class=eng_option)
parser.add_option("-R",
"--rx-subdev-spec",
type="subdev",
default=(0, 0),
help="select USRP Rx side A or B (default=A)")
parser.add_option(
"-d",
"--decim",
type="int",
default=16,
help="set fgpa decimation rate to DECIM [default=%default]")
parser.add_option("-f",
"--freq",
type="eng_float",
default=None,
help="set frequency to FREQ",
metavar="FREQ")
parser.add_option("-Q",
"--observing",
type="eng_float",
default=0.0,
help="set observing frequency to FREQ")
parser.add_option("-a",
"--avg",
type="eng_float",
default=1.0,
help="set spectral averaging alpha")
parser.add_option("-V",
"--favg",
type="eng_float",
default=2.0,
help="set folder averaging alpha")
parser.add_option("-g",
"--gain",
type="eng_float",
default=None,
help="set gain in dB (default is midpoint)")
parser.add_option("-l",
"--reflevel",
type="eng_float",
default=30.0,
help="Set pulse display reference level")
parser.add_option("-L",
"--lowest",
type="eng_float",
default=1.5,
help="Lowest valid frequency bin")
parser.add_option("-e",
"--longitude",
type="eng_float",
default=-76.02,
help="Set Observer Longitude")
parser.add_option("-c",
"--latitude",
type="eng_float",
default=44.85,
help="Set Observer Latitude")
parser.add_option("-F",
"--fft_size",
type="eng_float",
default=1024,
help="Size of FFT")
parser.add_option("-t",
"--threshold",
type="eng_float",
default=2.5,
help="pulsar threshold")
parser.add_option("-p",
"--lowpass",
type="eng_float",
default=100,
help="Pulse spectra cutoff freq")
parser.add_option("-P", "--prefix", default="./", help="File prefix")
parser.add_option("-u",
"--pulsefreq",
type="eng_float",
default=0.748,
help="Observation pulse rate")
parser.add_option("-D",
"--dm",
type="eng_float",
default=1.0e-5,
help="Dispersion Measure")
parser.add_option("-O",
"--doppler",
type="eng_float",
default=1.0,
help="Doppler ratio")
parser.add_option("-B",
"--divbase",
type="eng_float",
default=20,
help="Y/Div menu base")
parser.add_option("-I",
"--division",
type="eng_float",
default=100,
help="Y/Div")
parser.add_option("-A",
"--audio_source",
default="plughw:0,0",
help="Audio input device spec")
parser.add_option("-N",
"--num_pulses",
default=1,
type="eng_float",
help="Number of display pulses")
(options, args) = parser.parse_args()
if len(args) != 0:
parser.print_help()
sys.exit(1)
self.show_debug_info = True
self.reflevel = options.reflevel
self.divbase = options.divbase
self.division = options.division
self.audiodev = options.audio_source
self.mult = int(options.num_pulses)
# Low-pass cutoff for post-detector filter
# Set to 100Hz usually, since lots of pulsars fit in this
# range
self.lowpass = options.lowpass
# What is lowest valid frequency bin in post-detector FFT?
# There's some pollution very close to DC
self.lowest_freq = options.lowest
# What (dB) threshold to use in determining spectral candidates
self.threshold = options.threshold
# Filename prefix for recording file
self.prefix = options.prefix
# Dispersion Measure (DM)
self.dm = options.dm
# Doppler shift, as a ratio
# 1.0 == no doppler shift
# 1.005 == a little negative shift
# 0.995 == a little positive shift
self.doppler = options.doppler
#
# Input frequency and observing frequency--not necessarily the
# same thing, if we're looking at the IF of some downconverter
# that's ahead of the USRP and daughtercard. This distinction
# is important in computing the correct de-dispersion filter.
#
self.frequency = options.freq
if options.observing <= 0:
self.observing_freq = options.freq
else:
self.observing_freq = options.observing
# build the graph
self.u = usrp.source_c(decim_rate=options.decim)
self.u.set_mux(
usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec))
#
# Recording file, in case we ever need to record baseband data
#
self.recording = gr.file_sink(gr.sizeof_char, "/dev/null")
self.recording_state = False
self.pulse_recording = gr.file_sink(gr.sizeof_short, "/dev/null")
self.pulse_recording_state = False
#
# We come up with recording turned off, but the user may
# request recording later on
self.recording.close()
self.pulse_recording.close()
#
# Need these two for converting 12-bit baseband signals to 8-bit
#
self.tofloat = gr.complex_to_float()
self.tochar = gr.float_to_char()
# Need this for recording pulses (post-detector)
self.toshort = gr.float_to_short()
#
# The spectral measurer sets this when it has a valid
# average spectral peak-to-peak distance
# We can then use this to program the parameters for the epoch folder
#
# We set a sentimental value here
self.pulse_freq = options.pulsefreq
# Folder runs at this raw sample rate
self.folder_input_rate = 20000
# Each pulse in the epoch folder is sampled at 128 times the nominal
# pulse rate
self.folding = 128
#
# Try to find candidate parameters for rational resampler
#
save_i = 0
candidates = []
for i in range(20, 300):
input_rate = self.folder_input_rate
output_rate = int(self.pulse_freq * i)
interp = gru.lcm(input_rate, output_rate) / input_rate
decim = gru.lcm(input_rate, output_rate) / output_rate
if (interp < 500 and decim < 250000):
candidates.append(i)
# We didn't find anything, bail!
if (len(candidates) < 1):
print "Couldn't converge on resampler parameters"
sys.exit(1)
#
# Now try to find candidate with the least sampling error
#
mindiff = 999.999
for i in candidates:
diff = self.pulse_freq * i
diff = diff - int(diff)
if (diff < mindiff):
mindiff = diff
save_i = i
# Recompute rates
input_rate = self.folder_input_rate
output_rate = int(self.pulse_freq * save_i)
# Compute new interp and decim, based on best candidate
interp = gru.lcm(input_rate, output_rate) / input_rate
decim = gru.lcm(input_rate, output_rate) / output_rate
# Save optimized folding parameters, used later
self.folding = save_i
self.interp = int(interp)
self.decim = int(decim)
# So that we can view N pulses in the pulse viewer window
FOLD_MULT = self.mult
# determine the daughterboard subdevice we're using
self.subdev = usrp.selected_subdev(self.u, options.rx_subdev_spec)
self.cardtype = self.u.daughterboard_id(0)
# Compute raw input rate
input_rate = self.u.adc_freq() / self.u.decim_rate()
# BW==input_rate for complex data
self.bw = input_rate
#
# Set baseband filter bandwidth if DBS_RX:
#
if self.cardtype == usrp_dbid.DBS_RX:
lbw = input_rate / 2
if lbw < 1.0e6:
lbw = 1.0e6
self.subdev.set_bw(lbw)
#
# We use this as a crude volume control for the audio output
#
#self.volume = gr.multiply_const_ff(10**(-1))
#
# Create location data for ephem package
#
self.locality = ephem.Observer()
self.locality.long = str(options.longitude)
self.locality.lat = str(options.latitude)
#
# What is the post-detector LPF cutoff for the FFT?
#
PULSAR_MAX_FREQ = int(options.lowpass)
# First low-pass filters down to input_rate/FIRST_FACTOR
# and decimates appropriately
FIRST_FACTOR = int(input_rate / (self.folder_input_rate / 2))
first_filter = gr.firdes.low_pass(1.0, input_rate,
input_rate / FIRST_FACTOR,
input_rate / (FIRST_FACTOR * 20),
gr.firdes.WIN_HAMMING)
# Second filter runs at the output rate of the first filter,
# And low-pass filters down to PULSAR_MAX_FREQ*10
#
second_input_rate = int(input_rate / (FIRST_FACTOR / 2))
second_filter = gr.firdes.band_pass(1.0, second_input_rate, 0.10,
PULSAR_MAX_FREQ * 10,
PULSAR_MAX_FREQ * 1.5,
gr.firdes.WIN_HAMMING)
# Third filter runs at PULSAR_MAX_FREQ*20
# and filters down to PULSAR_MAX_FREQ
#
third_input_rate = PULSAR_MAX_FREQ * 20
third_filter = gr.firdes_band_pass(1.0, third_input_rate, 0.10,
PULSAR_MAX_FREQ,
PULSAR_MAX_FREQ / 10.0,
gr.firdes.WIN_HAMMING)
#
# Create the appropriate FFT scope
#
self.scope = ra_fftsink.ra_fft_sink_f(panel,
fft_size=int(options.fft_size),
sample_rate=PULSAR_MAX_FREQ * 2,
title="Post-detector spectrum",
ofunc=self.pulsarfunc,
xydfunc=self.xydfunc,
fft_rate=200)
#
# Tell scope we're looking from DC to PULSAR_MAX_FREQ
#
self.scope.set_baseband_freq(0.0)
#
# Setup stripchart for showing pulse profiles
#
hz = "%5.3fHz " % self.pulse_freq
per = "(%5.3f sec)" % (1.0 / self.pulse_freq)
sr = "%d sps" % (int(self.pulse_freq * self.folding))
times = " %d Pulse Intervals" % self.mult
self.chart = ra_stripchartsink.stripchart_sink_f(
panel,
sample_rate=1,
stripsize=self.folding * FOLD_MULT,
parallel=True,
title="Pulse Profiles: " + hz + per + times,
xlabel="Seconds @ " + sr,
ylabel="Level",
autoscale=True,
divbase=self.divbase,
scaling=1.0 / (self.folding * self.pulse_freq))
self.chart.set_ref_level(self.reflevel)
self.chart.set_y_per_div(self.division)
# De-dispersion filter setup
#
# Do this here, just before creating the filter
# that will use the taps.
#
ntaps = self.compute_disp_ntaps(self.dm, self.bw, self.observing_freq)
# Taps for the de-dispersion filter
self.disp_taps = Numeric.zeros(ntaps, Numeric.Complex64)
# Compute the de-dispersion filter now
self.compute_dispfilter(self.dm, self.doppler, self.bw,
self.observing_freq)
#
# Call constructors for receive chains
#
#
# Now create the FFT filter using the computed taps
self.dispfilt = gr.fft_filter_ccc(1, self.disp_taps)
#
# Audio sink
#
#print "input_rate ", second_input_rate, "audiodev ", self.audiodev
#self.audio = audio.sink(second_input_rate, self.audiodev)
#
# The three post-detector filters
# Done this way to allow an audio path (up to 10Khz)
# ...and also because going from xMhz down to ~100Hz
# In a single filter doesn't seem to work.
#
self.first = gr.fir_filter_fff(FIRST_FACTOR / 2, first_filter)
p = second_input_rate / (PULSAR_MAX_FREQ * 20)
self.second = gr.fir_filter_fff(int(p), second_filter)
self.third = gr.fir_filter_fff(10, third_filter)
# Detector
self.detector = gr.complex_to_mag_squared()
self.enable_comb_filter = False
# Epoch folder comb filter
if self.enable_comb_filter == True:
bogtaps = Numeric.zeros(512, Numeric.Float64)
self.folder_comb = gr.fft_filter_ccc(1, bogtaps)
# Rational resampler
self.folder_rr = blks2.rational_resampler_fff(self.interp, self.decim)
# Epoch folder bandpass
bogtaps = Numeric.zeros(1, Numeric.Float64)
self.folder_bandpass = gr.fir_filter_fff(1, bogtaps)
# Epoch folder F2C/C2F
self.folder_f2c = gr.float_to_complex()
self.folder_c2f = gr.complex_to_float()
# Epoch folder S2P
self.folder_s2p = gr.serial_to_parallel(gr.sizeof_float,
self.folding * FOLD_MULT)
# Epoch folder IIR Filter (produces average pulse profiles)
self.folder_iir = gr.single_pole_iir_filter_ff(
1.0 / options.favg, self.folding * FOLD_MULT)
#
# Set all the epoch-folder goop up
#
self.set_folding_params()
#
# Start connecting configured modules in the receive chain
#
# Connect raw USRP to de-dispersion filter, detector
self.connect(self.u, self.dispfilt, self.detector)
# Connect detector output to FIR LPF
# in two stages, followed by the FFT scope
self.connect(self.detector, self.first, self.second, self.third,
self.scope)
# Connect audio output
#self.connect(self.first, self.volume)
#self.connect(self.volume, (self.audio, 0))
#self.connect(self.volume, (self.audio, 1))
# Connect epoch folder
if self.enable_comb_filter == True:
self.connect(self.first, self.folder_bandpass, self.folder_rr,
self.folder_f2c, self.folder_comb, self.folder_c2f,
self.folder_s2p, self.folder_iir, self.chart)
else:
self.connect(self.first, self.folder_bandpass, self.folder_rr,
self.folder_s2p, self.folder_iir, self.chart)
# Connect baseband recording file (initially /dev/null)
self.connect(self.u, self.tofloat, self.tochar, self.recording)
# Connect pulse recording file (initially /dev/null)
self.connect(self.first, self.toshort, self.pulse_recording)
#
# Build the GUI elements
#
self._build_gui(vbox)
# Make GUI agree with command-line
self.myform['average'].set_value(int(options.avg))
self.myform['foldavg'].set_value(int(options.favg))
# Make spectral averager agree with command line
if options.avg != 1.0:
self.scope.set_avg_alpha(float(1.0 / options.avg))
self.scope.set_average(True)
# set initial values
if options.gain is None:
# if no gain was specified, use the mid-point in dB
g = self.subdev.gain_range()
options.gain = float(g[0] + g[1]) / 2
if options.freq is None:
# if no freq was specified, use the mid-point
r = self.subdev.freq_range()
options.freq = float(r[0] + r[1]) / 2
self.set_gain(options.gain)
#self.set_volume(-10.0)
if not (self.set_freq(options.freq)):
self._set_status_msg("Failed to set initial frequency")
self.myform['decim'].set_value(self.u.decim_rate())
self.myform['fs@usb'].set_value(self.u.adc_freq() /
self.u.decim_rate())
self.myform['dbname'].set_value(self.subdev.name())
self.myform['DM'].set_value(self.dm)
self.myform['Doppler'].set_value(self.doppler)
#
# Start the timer that shows current LMST on the GUI
#
self.lmst_timer.Start(1000)
def __init__(self, frame, panel, vbox, argv):
stdgui2.std_top_block.__init__(self, frame, panel, vbox, argv)
self.frame = frame
self.panel = panel
parser = OptionParser(option_class=eng_option)
parser.add_option("-R", "--rx-subdev-spec", type="subdev", default=(0, 0),
help="select USRP Rx side A or B (default=A)")
parser.add_option("-d", "--decim", type="int", default=16,
help="set fgpa decimation rate to DECIM [default=%default]")
parser.add_option("-f", "--freq", type="eng_float", default=None,
help="set frequency to FREQ", metavar="FREQ")
parser.add_option("-Q", "--observing", type="eng_float", default=0.0,
help="set observing frequency to FREQ")
parser.add_option("-a", "--avg", type="eng_float", default=1.0,
help="set spectral averaging alpha")
parser.add_option("-V", "--favg", type="eng_float", default=2.0,
help="set folder averaging alpha")
parser.add_option("-g", "--gain", type="eng_float", default=None,
help="set gain in dB (default is midpoint)")
parser.add_option("-l", "--reflevel", type="eng_float", default=30.0,
help="Set pulse display reference level")
parser.add_option("-L", "--lowest", type="eng_float", default=1.5,
help="Lowest valid frequency bin")
parser.add_option("-e", "--longitude", type="eng_float", default=-76.02, help="Set Observer Longitude")
parser.add_option("-c", "--latitude", type="eng_float", default=44.85, help="Set Observer Latitude")
parser.add_option("-F", "--fft_size", type="eng_float", default=1024, help="Size of FFT")
parser.add_option ("-t", "--threshold", type="eng_float", default=2.5, help="pulsar threshold")
parser.add_option("-p", "--lowpass", type="eng_float", default=100, help="Pulse spectra cutoff freq")
parser.add_option("-P", "--prefix", default="./", help="File prefix")
parser.add_option("-u", "--pulsefreq", type="eng_float", default=0.748, help="Observation pulse rate")
parser.add_option("-D", "--dm", type="eng_float", default=1.0e-5, help="Dispersion Measure")
parser.add_option("-O", "--doppler", type="eng_float", default=1.0, help="Doppler ratio")
parser.add_option("-B", "--divbase", type="eng_float", default=20, help="Y/Div menu base")
parser.add_option("-I", "--division", type="eng_float", default=100, help="Y/Div")
parser.add_option("-A", "--audio_source", default="plughw:0,0", help="Audio input device spec")
parser.add_option("-N", "--num_pulses", default=1, type="eng_float", help="Number of display pulses")
(options, args) = parser.parse_args()
if len(args) != 0:
parser.print_help()
sys.exit(1)
self.show_debug_info = True
self.reflevel = options.reflevel
self.divbase = options.divbase
self.division = options.division
self.audiodev = options.audio_source
self.mult = int(options.num_pulses)
# Low-pass cutoff for post-detector filter
# Set to 100Hz usually, since lots of pulsars fit in this
# range
self.lowpass = options.lowpass
# What is lowest valid frequency bin in post-detector FFT?
# There's some pollution very close to DC
self.lowest_freq = options.lowest
# What (dB) threshold to use in determining spectral candidates
self.threshold = options.threshold
# Filename prefix for recording file
self.prefix = options.prefix
# Dispersion Measure (DM)
self.dm = options.dm
# Doppler shift, as a ratio
# 1.0 == no doppler shift
# 1.005 == a little negative shift
# 0.995 == a little positive shift
self.doppler = options.doppler
#
# Input frequency and observing frequency--not necessarily the
# same thing, if we're looking at the IF of some downconverter
# that's ahead of the USRP and daughtercard. This distinction
# is important in computing the correct de-dispersion filter.
#
self.frequency = options.freq
if options.observing <= 0:
self.observing_freq = options.freq
else:
self.observing_freq = options.observing
# build the graph
self.u = usrp.source_c(decim_rate=options.decim)
self.u.set_mux(usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec))
#
# Recording file, in case we ever need to record baseband data
#
self.recording = gr.file_sink(gr.sizeof_char, "/dev/null")
self.recording_state = False
self.pulse_recording = gr.file_sink(gr.sizeof_short, "/dev/null")
self.pulse_recording_state = False
#
# We come up with recording turned off, but the user may
# request recording later on
self.recording.close()
self.pulse_recording.close()
#
# Need these two for converting 12-bit baseband signals to 8-bit
#
self.tofloat = gr.complex_to_float()
self.tochar = gr.float_to_char()
# Need this for recording pulses (post-detector)
self.toshort = gr.float_to_short()
#
# The spectral measurer sets this when it has a valid
# average spectral peak-to-peak distance
# We can then use this to program the parameters for the epoch folder
#
# We set a sentimental value here
self.pulse_freq = options.pulsefreq
# Folder runs at this raw sample rate
self.folder_input_rate = 20000
# Each pulse in the epoch folder is sampled at 128 times the nominal
# pulse rate
self.folding = 128
#
# Try to find candidate parameters for rational resampler
#
save_i = 0
candidates = []
for i in range(20,300):
input_rate = self.folder_input_rate
output_rate = int(self.pulse_freq * i)
interp = gru.lcm(input_rate, output_rate) / input_rate
decim = gru.lcm(input_rate, output_rate) / output_rate
if (interp < 500 and decim < 250000):
candidates.append(i)
# We didn't find anything, bail!
if (len(candidates) < 1):
print "Couldn't converge on resampler parameters"
sys.exit(1)
#
# Now try to find candidate with the least sampling error
#
mindiff = 999.999
for i in candidates:
diff = self.pulse_freq * i
diff = diff - int(diff)
if (diff < mindiff):
mindiff = diff
save_i = i
# Recompute rates
input_rate = self.folder_input_rate
output_rate = int(self.pulse_freq * save_i)
# Compute new interp and decim, based on best candidate
interp = gru.lcm(input_rate, output_rate) / input_rate
decim = gru.lcm(input_rate, output_rate) / output_rate
# Save optimized folding parameters, used later
self.folding = save_i
self.interp = int(interp)
self.decim = int(decim)
# So that we can view N pulses in the pulse viewer window
FOLD_MULT=self.mult
# determine the daughterboard subdevice we're using
self.subdev = usrp.selected_subdev(self.u, options.rx_subdev_spec)
self.cardtype = self.u.daughterboard_id(0)
# Compute raw input rate
input_rate = self.u.adc_freq() / self.u.decim_rate()
# BW==input_rate for complex data
self.bw = input_rate
#
# Set baseband filter bandwidth if DBS_RX:
#
if self.cardtype == usrp_dbid.DBS_RX:
lbw = input_rate / 2
if lbw < 1.0e6:
lbw = 1.0e6
self.subdev.set_bw(lbw)
#
# We use this as a crude volume control for the audio output
#
#self.volume = gr.multiply_const_ff(10**(-1))
#
# Create location data for ephem package
#
self.locality = ephem.Observer()
self.locality.long = str(options.longitude)
self.locality.lat = str(options.latitude)
#
# What is the post-detector LPF cutoff for the FFT?
#
PULSAR_MAX_FREQ=int(options.lowpass)
# First low-pass filters down to input_rate/FIRST_FACTOR
# and decimates appropriately
FIRST_FACTOR=int(input_rate/(self.folder_input_rate/2))
first_filter = gr.firdes.low_pass (1.0,
input_rate,
input_rate/FIRST_FACTOR,
input_rate/(FIRST_FACTOR*20),
gr.firdes.WIN_HAMMING)
# Second filter runs at the output rate of the first filter,
# And low-pass filters down to PULSAR_MAX_FREQ*10
#
second_input_rate = int(input_rate/(FIRST_FACTOR/2))
second_filter = gr.firdes.band_pass(1.0, second_input_rate,
0.10,
PULSAR_MAX_FREQ*10,
PULSAR_MAX_FREQ*1.5,
gr.firdes.WIN_HAMMING)
# Third filter runs at PULSAR_MAX_FREQ*20
# and filters down to PULSAR_MAX_FREQ
#
third_input_rate = PULSAR_MAX_FREQ*20
third_filter = gr.firdes_band_pass(1.0, third_input_rate,
0.10, PULSAR_MAX_FREQ,
PULSAR_MAX_FREQ/10.0,
gr.firdes.WIN_HAMMING)
#
# Create the appropriate FFT scope
#
self.scope = ra_fftsink.ra_fft_sink_f (panel,
fft_size=int(options.fft_size), sample_rate=PULSAR_MAX_FREQ*2,
title="Post-detector spectrum",
ofunc=self.pulsarfunc, xydfunc=self.xydfunc, fft_rate=200)
#
# Tell scope we're looking from DC to PULSAR_MAX_FREQ
#
self.scope.set_baseband_freq (0.0)
#
# Setup stripchart for showing pulse profiles
#
hz = "%5.3fHz " % self.pulse_freq
per = "(%5.3f sec)" % (1.0/self.pulse_freq)
sr = "%d sps" % (int(self.pulse_freq*self.folding))
times = " %d Pulse Intervals" % self.mult
self.chart = ra_stripchartsink.stripchart_sink_f (panel,
sample_rate=1,
stripsize=self.folding*FOLD_MULT, parallel=True, title="Pulse Profiles: "+hz+per+times,
xlabel="Seconds @ "+sr, ylabel="Level", autoscale=True,
divbase=self.divbase, scaling=1.0/(self.folding*self.pulse_freq))
self.chart.set_ref_level(self.reflevel)
self.chart.set_y_per_div(self.division)
# De-dispersion filter setup
#
# Do this here, just before creating the filter
# that will use the taps.
#
ntaps = self.compute_disp_ntaps(self.dm,self.bw,self.observing_freq)
# Taps for the de-dispersion filter
self.disp_taps = Numeric.zeros(ntaps,Numeric.Complex64)
# Compute the de-dispersion filter now
self.compute_dispfilter(self.dm,self.doppler,
self.bw,self.observing_freq)
#
# Call constructors for receive chains
#
#
# Now create the FFT filter using the computed taps
self.dispfilt = gr.fft_filter_ccc(1, self.disp_taps)
#
# Audio sink
#
#print "input_rate ", second_input_rate, "audiodev ", self.audiodev
#self.audio = audio.sink(second_input_rate, self.audiodev)
#
# The three post-detector filters
# Done this way to allow an audio path (up to 10Khz)
# ...and also because going from xMhz down to ~100Hz
# In a single filter doesn't seem to work.
#
self.first = gr.fir_filter_fff (FIRST_FACTOR/2, first_filter)
p = second_input_rate / (PULSAR_MAX_FREQ*20)
self.second = gr.fir_filter_fff (int(p), second_filter)
self.third = gr.fir_filter_fff (10, third_filter)
# Detector
self.detector = gr.complex_to_mag_squared()
self.enable_comb_filter = False
# Epoch folder comb filter
if self.enable_comb_filter == True:
bogtaps = Numeric.zeros(512, Numeric.Float64)
self.folder_comb = gr.fft_filter_ccc(1,bogtaps)
# Rational resampler
self.folder_rr = blks2.rational_resampler_fff(self.interp, self.decim)
# Epoch folder bandpass
bogtaps = Numeric.zeros(1, Numeric.Float64)
self.folder_bandpass = gr.fir_filter_fff (1, bogtaps)
# Epoch folder F2C/C2F
self.folder_f2c = gr.float_to_complex()
self.folder_c2f = gr.complex_to_float()
# Epoch folder S2P
self.folder_s2p = gr.serial_to_parallel (gr.sizeof_float,
self.folding*FOLD_MULT)
# Epoch folder IIR Filter (produces average pulse profiles)
self.folder_iir = gr.single_pole_iir_filter_ff(1.0/options.favg,
self.folding*FOLD_MULT)
#
# Set all the epoch-folder goop up
#
self.set_folding_params()
#
# Start connecting configured modules in the receive chain
#
# Connect raw USRP to de-dispersion filter, detector
self.connect(self.u, self.dispfilt, self.detector)
# Connect detector output to FIR LPF
# in two stages, followed by the FFT scope
self.connect(self.detector, self.first,
self.second, self.third, self.scope)
# Connect audio output
#self.connect(self.first, self.volume)
#self.connect(self.volume, (self.audio, 0))
#self.connect(self.volume, (self.audio, 1))
# Connect epoch folder
if self.enable_comb_filter == True:
self.connect (self.first, self.folder_bandpass, self.folder_rr,
self.folder_f2c,
self.folder_comb, self.folder_c2f,
self.folder_s2p, self.folder_iir,
self.chart)
else:
self.connect (self.first, self.folder_bandpass, self.folder_rr,
self.folder_s2p, self.folder_iir, self.chart)
# Connect baseband recording file (initially /dev/null)
self.connect(self.u, self.tofloat, self.tochar, self.recording)
# Connect pulse recording file (initially /dev/null)
self.connect(self.first, self.toshort, self.pulse_recording)
#
# Build the GUI elements
#
self._build_gui(vbox)
# Make GUI agree with command-line
self.myform['average'].set_value(int(options.avg))
self.myform['foldavg'].set_value(int(options.favg))
# Make spectral averager agree with command line
if options.avg != 1.0:
self.scope.set_avg_alpha(float(1.0/options.avg))
self.scope.set_average(True)
# set initial values
if options.gain is None:
# if no gain was specified, use the mid-point in dB
g = self.subdev.gain_range()
options.gain = float(g[0]+g[1])/2
if options.freq is None:
# if no freq was specified, use the mid-point
r = self.subdev.freq_range()
options.freq = float(r[0]+r[1])/2
self.set_gain(options.gain)
#self.set_volume(-10.0)
if not(self.set_freq(options.freq)):
self._set_status_msg("Failed to set initial frequency")
self.myform['decim'].set_value(self.u.decim_rate())
self.myform['fs@usb'].set_value(self.u.adc_freq() / self.u.decim_rate())
self.myform['dbname'].set_value(self.subdev.name())
self.myform['DM'].set_value(self.dm)
self.myform['Doppler'].set_value(self.doppler)
#
# Start the timer that shows current LMST on the GUI
#
self.lmst_timer.Start(1000)