Sidebar
Table of Contents
Medusa VLBI
Medusa is a GPU cluster used for backend processing of the Parkes UWL receiver. The UWL receiver has digitizers dedicated to the receiver in the focus cabin. There are also digitizers in the tower connected to the “legacy” downconversion system. The tower/legacy digitizers are limited to 1 GHz bandwidth (the bandwidth of the legacy system).
Experiment Setup
- Run
vex2medusa.pl <exper.vex>on Marfield Unix systems, and copy to joffrey LBA area as pksobs (looks for antenna 'Md“, can be changed with-antenna XXoption - On joffrey run:
cd lba/medusa ./run_vlbicontrol.sh
This starts the vlbiControl pyqt5 gui. To load an experiment click on File→Load Experiment then select the XML file for this experiment.
Start the experiment by clicking the Start button. This will configure and start Medusa and start the Flexbuf recorder running. It will NOT control the antenna or any of the IF setup.
VLBI Observing with Legacy Receivers
Proper notes to be added
- Create Medusa config, if required (e.g. no config exists for this Rx/LO setup):
uwb_config.py {-freq <FREQ> | -DAS <FREQ> }
Copy output to medusa-srv0:/home/uwb/linux_64/share/medusa_configs. The passed frequency is the centre of the observing band. If the band is inverted, pass the -i option
- Change Medusa config file (stop and restart needed)
- Configure Switch Matrix appropriately
smrun MED64Nif using LBA DAS orsmrun MED900Nif “1 GHz” bandwidth
Note that Medusa can be run in parallel with the LBA DAS, but in this case the Parkes downconversion will be configured to 64 MHz bandwidth per IF. This limits the total bandwidth available to Medusa to 64 MHz. If more bandwidth is required, the LBA DAS cannot be used.
