--- /dev/null
+This program is used to analyse pulsars of known parameters. It contains
+ both a post-detector spectral display, and a "pulse profile" display.
+ It has a built-in de-dispersion filter that will work up to DM=100 for
+ 21cm observing, and up to DM=5 for 327Mhz observing.
+
+The program takes the following options:
+
+ --rx-subdev-spec which USRP Rx side? A or B
+
+ --decim USRP decimation rate use either 64 or 128
+
+ --freq USRP daughtercard frequency
+
+ --observing Actual observing frequency (default is to use the
+ setting for --freq)
+
+ --avg Averaging setting for spectral display--higher numbers
+ equal more averaging. 25 to 40 is typical.
+
+ --favg Pulse folding averaging. 2 to 5 is typical.
+
+ --gain USRP daughtercard gain control
+
+ --reflevel Reference level on pulse profile display
+
+ --lowest Lowest spectral bin that is considered valid, in Hz
+
+ --longitude Observer longitude: West is negative
+
+ --latitude Observer latitude: South is negative
+
+ --fft_size Size of FFT for post-detector spectrum: default is 1024
+
+ --threshold Threshold (dB) to be considered a spectral "peak"
+ This is relative to the average spectral level
+
+ --lowpass Low pass frequency for post-detector spectral display
+ 20-100 is typical
+
+ --prefix Filename prefix to use for recording files
+ Default is ./
+
+ --pulsefreq The frequency of the expected pulses
+ For sentimental reasons, this defaults to 0.748Hz
+
+ --dm The DM
+
+ --doppler The doppler shift, as a ratio
+
+ --divbase The base of the Y/Div menu in pulsar display
+
+ --division The initial Y/Div in pulsar display
+
+DM, Doppler, Gain, Frequency, and the averaging parameters can all be
+ changed using the GUI at runtime.
+
+If latitude and longitude are set correctly, and the system time is
+ correct, then the current LMST is displayed below the frequency
+ input, updated once per second.
+
+Moving the mouse in the post-detector spectrum display shows you that
+ point in the post-detector spectrum, both frequency and signal level.
+
+The post-detector spectrum is analysed, with results shown below
+ "Best freq". It shows the spectral peaks, and computes their relationship.
+ It shows the harmonic compliance among the peaks, as well as the average
+ peak-to-peak distance.
+
+
+Here's a complete example for observing a pulsar with a frequency of
+ 1.35Hz, at 431.5Mhz, using an IF of 10.7Mhz, and a DM of 12.431, using
+ 1Mhz observing bandwidth:
+
+./usrp_psr_receiver.py --freq 10.7e6 --decim 64 --dm 12.431 --avg 35 \
+ --pulsefreq 1.35 --fft_size 2048 --lowest 1.00 --gain 75 --threshold 11.5 \
+ --observing 431.5e6 --reflevel 200 --division 100 --divbase 10 --favg 3 \
+ --lowpass 20 --longitude -76.02 --latitude 44.95
+
+Since the observed pulsar is at 1.35Hz, a lowpass cutoff for the
+ post-detector spectral display of 20Hz will be adequate. We
+ tell the spectral analyser to use a threshold of 11.5dB above
+ average when analysing spectral data, and set the epoch folder
+ averager (pulse profile display) to use an average from 3 samples.
+ Notice that our actual USRP/Daughtercard frequency is 10.7Mhz, while
+ our observing frequency is 431.5Mhz--this is important in order for
+ the DM de-dispersion calculations to be correct. We also set our
+ latitude and longitude, so that logfiles and the LMST display
+ will have the correct LMST in them.
+
+The entire complex baseband can be recorded, if the "Recording baseband"
+ button is pressed. Filenames are generated dynamically, and a header
+ file is produced giving observation parameters. The baseband data are
+ recorded as octet pairs: one for I and one for Q. Pressing the button again
+ turns off baseband recording. This baseband is "raw", so it will
+ not have been de-dispersed. The data rate will be whatever the
+ USRP was programmed to at the time (based on --decim).
+
+ The files are: YYYYMMDDHHMM.pdat and YYYYMMDDHHMM.phdr
+
+ The .phdr file contains ASCII header information describing the
+ contents of the .pdat file.
+
+Similarly the raw, pre-folded, band-limited post-detector "audio" data can be
+ recorded using the "Record Pulses" button. The data rate for these is
+ currently 20Khz, recorded as short integers. Just like baseband recording,
+ pressing the button again turns off pulse recording.
+
+ The files are: YYYYMMDDHHMM.padat and YYMMDDHHMM.pahdr
+
+ The .pahdr file is ascii text providing information about the contents
+ of the corresponding .padat file.
projects / debian / gnuradio / blobdiff