DSPSR user documentation: dspsr

Folding Survey Candidates

A new survey candidate has very few parameters: the spin period, trial dispersion measure, and perhaps an acceleration. These can be input to dspsr using a simple text file; for example: 
SOURCE: SC0001_04151
PERIOD: 1.362819517 s
DM: 50.6
ACC: 42.70 (m/s/s)
RA: 09:10:18
DEC: -72:07:35
Note that:
  • Each key/value pair is a single line: "KEY: value".
  • Key matching is case sensitive, and requires the colon (with no whitespace between the keyword and the colon).
  • Everything after the value is ignored.
  • It is necessary to specify PERIOD (in seconds) before ACC (acceleration in m/s/s).
  • By default, dspsr assumes that the epoch of the spin period is the start of the observation. To specify a different epoch (e.g. the middle of the observation) use the EPOCH key with value specified as MJD.
  • As an alternative to ACC, it is also possible to specify PDOT
  • As an alternative to PERIOD, it is also possible to specify TELESCOPE and BARYPERIOD. The TELESCOPE value must be a telescope code that is recognized by tempo or tempo2 (which are used to get the ITRF coordinates of the telescope).
This file is input to dspsr as a phase predictor using the -P command-line option; e.g. if the above example were saved as accel.txt and the raw data were in pointing.dat: 
dspsr -P accel.txt pointing.dat
This will produce a single folded profile, integrated over the duration of the observation stored in pointing.dat. To produce multiple sub-integrations, use the -L command-line option; e.g. to produce 10-second sub-integrations: 
dspsr -P accel.txt -L 10 pointing.dat
Each sub-integration will be written to a different file; it is also possible, though less memory-efficient, to produce a single file containing multiple sub-integrations with the -A option.