How to Record Data using WUPPI
Below listed are the instructions to record pulsar data using WUPPI. All commands presented here should be run on the tofu command line from your own account.
1. Check for Data Flow
First, follow the steps listed in the WUPPIUser'sGuide to make sure the bee2 is initialized properly, signal input levels are correct, and data is being sent over the network and received on tofu. You should also look at WUPPIUser'sGuide if you want to tweak the observing bandwidth of WUPPI or the sampling rate of the data that WUPPI sends to tofu. If you do not see packets flowing, stop now and figure out why! Continuing with the instructions on this page will be pointless. If that all worked well, though, quit the test_net_thread job by doing a 'ctrl-C'.
If you previously opened a monitor program (i.e. guppi_monitor), exit it now before continuing.
2. Set up environment
Open an xterm and source wuppi.csh or wuppi.bash as appropriate for your login shell:
[user@tofu ~]$ source /opt/64bit/wuppiI/wuppi.csh
3. Set WUPPI Status Parameters
Set up the WUPPI status buffer. we have a program namely wuppiSet that sets the wuppi parmetrs and updates the 43m status in WUPPI shared memory. The command used for that is
[user@tofu ~]$ wuppiSet 1 source name time of observation(sec)
Here the 1 is the scan number and will be incremented when you make more than one scan on the same source. Also there are parameters like the amount of time you
take data and the source name which can be changed for every observation.
The program wuppiSet mainly executes the guppi_set_params command and sets the wuppi status parameters. This program is located at:
Complete information for guppi_set_params can be found with the command:
[user@tofu ~]$ guppi_set_params -h
Also further details about the guppi_set_params can be found at GUPPIDataTakingGuide in the GUPPIUser'sGuide.
4. Data acquisition
The command used for recording the data is
[user@tofu ~]$ guppi_search
Remember to stay in the directory where you want the data to end up. After giving this command data acquisition process starts and fits files are generated.
The directory we are working now is /data/scratch/glangsto/wuppi.After the observations are done we transfer the data to an mounted external hard drive at:
For 800 MHz observations, by default the data recorded is at a time resolution of 40.96us with 2048-channels and Full Stokes.
Folding the data
The data obtained in the fits format is folded using the command:
[user@tofu ~]$ prepfold -psr pulsarname -nosearch filename.fits