Carrying out a search-mode observation using a single beam
Currently search mode observations can be carried out using the PDFB3, PDFB4, BPSR and the analogue filerbank. The most flexibility is currently provided by the PDFB systems.
First a tcs schedule file needs to be created. An example is given below for PDFB4:
J1412+0224_R; P 14:12:00 +02:24:00; d4_cfg srch_256_512; d4_frq 1369.0; d4_tcyc 10; rcvr MULTI; tobs 60; mode srchset; sr4_nsblk 2048; sr4_btc 1.0; sr4_nbit 8; sr4_nprod 1; sr4_tsmp 1000
J1412+0224;P 14:12:15.80 +02:24:33.9; mode srch; tobs 3600
#symbols are ignored and can be used to provide comments on a schedule line.
- The first column
J1412+0224gives the name of the calibrator source and of the pulsar (or candidate position)
- The command
P 14:12:00 +02:24:00defines the calibrator/source position
d4_cfggives the requested bandwidth and number of channels. Available configurations are:
d4_frqgives the requested observing frequency (in MHz)
d4_tcycthe requested cycle time (in seconds)
rcvrthe receiver to use
tobsthe observation time (in seconds)
sr4_nsblkthe number of samples per block
sr4_nbitthe number of bits per sample (2, 4 or 8)
sr4_nprodthe number of products (1 = total intensity, 2 = AA and BB, 3 = full Stokes)
sr4_tsmpthe sampling time in microseconds
Note that the first line carries out a routine that sets the levels of the system using the pulsed cal (
mode srchset) whereas the second line actually carries out the observation (
- Make sure that the search mode has been selected on the tcs gui for PDFB4 (this is not done automatically by the schedule).
The output is a standard PSRFITS search mode file that can be processed using:
dspsr- can fold the data to produce archives
searchplot- allows the data to be plotted
A list of the available configurations for PDFB4 are available here.
- A feature that automatically closes one file and opens another for writing is currently been tested. This feature is necessary to stop individual files from becoming too large.