|Panos Labropoulos & Vamsi Krishna Veligatla
| Modern arrays like LOFAR include non-coplanar baselines. Sources away from the phase center are distorted due the phase difference caused by non-isoplanaticity (w-term, see Cornwell et al. (2008) and EVLA Memo 67). This effect grows more significant for low frequencies, long baselines and large Fields of View. Several algorithms exist to account for this effect and they all share one common feature: they are slow!
We have developed an experimental, yet compact and optimized imager that uses Graphics Processing Units (GPUs), to accelerate the computation. Initial benchmarks indicate that the computational speed is 5 to 6 times faster when compared with the CASA imager. Using multiple GPUs per system can help accelerate the computation even further. The next milestone would be to correct for direction-dependent effects during imaging.
This is work in progress and we are still far from making a public release.
|ASTRON and Kapteyn Astronomical Institute