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+0224_R and J1412+0224 gives the name of the calibrator source and of the pulsar (or candidate position)
• The command P 14:12:00 +02:24:00 defines the calibrator/source position
• d4_cfg gives the requested bandwidth and number of channels. Available configurations are: srch_1024_512,srch_256_1024, src_256_512, srch_512_512
• d4_frq gives the requested observing frequency (in MHz)
• d4_tcyc the requested cycle time (in seconds)
• rcvr the receiver to use
• tobs the observation time (in seconds)
• sr4_nsblk the number of samples per block
• sr4_nbit the number of bits per sample (2, 4 or 8)
• sr4_nprod the number of products (1 = total intensity, 2 = AA and BB, 3 = full Stokes)
• sr4_tsmp the 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 (mode srch).

• 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

Configurations

A list of the available configurations for PDFB4 are available here.

In progress

• 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.

Known issues