Aperture Array Simulations

The OSKAR Project All digital, aperture array simulation for an SKA station. Very general approach to system design for digital beamforming.

The People S. Salvini, M. Jones, B. Mort, F. Dulwich, K. Zarb-Adami, A. Trefethen, S. Rawlings Oxford e-Research Centre and Astrophysics. Collaboration with other SKADS groups from the UK.

On the Web Wiki: http://wiki.oerc.ox.ac.uk/Oskar

The OSKAR Station Simulator

Scope and Goals Narrowband (pre-channelised), all digital system. Scalable to large numbers of antennas (~105). Choice of number of beams and channels (limited by available processing power). Simulation of noise, other time variable corruptions, corrections.

Design Parallelised and scalable. Hierarchical. Separate data paths for signal and

beamforming weights. Simplified beamforming math. Modular framework with data checkpoints.

Using the OSKAR simulator

A tool to investigate… System design. Beamformer performance.

Targets Processing structure design. Processing hierarchy. Beam patterns. Array configuration, antenna response. Algorithmic aspects. Beam corrections. Noise performance.

Extensible parallel framework with flexible communication structure.

Emerging technologies

SKA station beamforming is a BIG problem… ~1017 flops per 1000 beams per 1024 channels! ~102 IBM Blue Genes, 104 clusters per station!

Cutting OSKAR data stream allows for experimenting on alternative architectures GPU (SIMD, stream architecture) Gate arrays / FPGAs Massively multicore. ASIC.

Summary

OSKAR: simulation of all-digital, aperture array beamforming for an SKA station.

Modular, flexible, parallel simulator framework to investigate beamforming and system design.

OSKAR to be delivered Spring 2009 Project wiki: http://wiki.oerc.ox.ac.uk/Oskar