1 This program is used to take spectra and total power measurements.
2 It records spectral and total-power data to external datalogging
5 The program takes the following options:
7 --rx-subdev-spec which USRP Rx side? A or B
9 --decim USRP decimation rate: 8, 16, 32, and 64 are good
10 (8Mhz, 4Mhz, 2Mhz, and 1Mhz bandwidth)
12 --freq USRP daughtercard frequency
14 --observing Actual observing frequency (default is to use the
17 --avg Averaging setting for spectral display--higher numbers
18 equal more averaging. 25 to 40 is typical.
20 --integ Total power integration time: seconds
22 --gain USRP daughtercard gain control
24 --reflevel Reference level on pulse profile display
26 --longitude Observer longitude: West is negative
28 --latitude Observer latitude: South is negative
30 --fft_size Size of FFT for post-detector spectrum: default is 1024
32 --prefix Filename prefix to use for data logging files
35 --divbase The base of the Y/Div menu in pulsar display
37 --division The initial Y/Div in pulsar display
41 --cfunc The function name prefix for the spectral and
44 --waterfall Use waterfall, rather than regular spectral display
45 NOT TESTED IN THIS APPLICATION
47 --stripsize Size of the total-power stripchart, in samples
49 There are two windows--a spectral window, and the total-power window.
50 Moving the cursor around in the spectral window shows you the
51 corresponding frequency and doppler shift. Left clicking in this
52 window sets an interference marker, which sets a "zero" in the
53 interference filter. Use the "clear interference" button to clear this.
55 The total power window is updated at a fixed 2Hz rate, and grows from
56 the left of the display.
58 If latitude and longitude are set correctly, and system time is correct,
59 then the current LMST is displayed, updated once per second.
61 Averaging parameters, gain, and frequency can all be set from the GUI using
62 the appropriate controls. You can also enter the current declination, which
63 will appear in the datalogging files. This is useful both for mapping,
64 and housekeeping purposes, particularly when you haven't looked at a datafile
67 There are two datalog files produced by this program:
69 YYYYMMDDHH.tpdat Total power data
71 The date/time portion of the filename is referred to local time,
72 rather than UTC or sidereal.
74 First field is sidereal time when sample was taken
75 Second field is total power datum
76 Third field is declination in decimal degrees
78 Samples are written once per second
80 YYYYMMDDHH.sdat Spectral data
82 The date/time portion of the filename is referred to local time,
83 rather than UTC or sidereal.
85 First field is sidereal time when spectrum was taken
86 Second field is declination in decimal degrees
87 Third field is complex spectral data--in the same order that FFTW3 library
88 places bins: DC to bandwidth/2, followed by -bandwidth/2 to DC.
90 Spectral snapshots are written once every 5 seconds