BLADE
Split, combine, and compare the signals from many antennas the way a working radio telescope does.
Provides blocks
Overview
A radio telescope built from many dishes only becomes one instrument once their signals are combined. The Allen Telescope Array started with 42 dishes about 6 m across,[1] and every one of them delivers its own stream of voltages. A backend splits each stream into narrow frequency channels, then either adds the antennas together with the right phase to point a beam at one spot on the sky, or multiplies every pair of antennas to measure the structure of the whole field of view.[2]
The BLADE plugin, short for Breakthrough Listen Accelerated DSP Engine, brings those steps to CyberEther as blocks.[3] Every block runs on the CPU, and all but the Phasor also run on CUDA when the CUDA toolkit is available, compiling their kernels just in time for the tensor shapes flowing through the flowgraph. The blocks began as the beamforming engine of the Allen Telescope Array and run there in production.
| Block | What it does |
|---|---|
| Channelizer | Splits coarse frequency channels into finer ones. |
| Phasor | Calculates the per-antenna phase weights that point each beam. |
| Beamformer | Forms coherent beams from antenna voltages and phasors.[2] |
| Correlator | Correlates every antenna pair into visibilities for imaging.[2] |
| Polarizer | Converts dual linear polarization to circular, or extracts one linear component. |
| Detector | Turns voltages into power and integrates it. |
| Integrator | Sums samples along an axis. |
| Stacker | Stacks its input along an axis. |
Documentation
The Stelline documentation has a reference page for each BLADE block, with its inputs, outputs, and configuration and how it runs on the CPU and on CUDA. The Beamformer and Correlator pages are the place to start. Pairing BLADE with the Stelline plugin adds live telescope capture and standard file output, the full chain the Allen Telescope Array uses.
The plugin ships as a bundle built for each CyberEther release, so download the one that matches your version. Installing plugins covers loading it.
References
References
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J. Welch et al., "The Allen Telescope Array: The first widefield, panchromatic, snapshot radio camera for radio astronomy and SETI," Proc. IEEE, vol. 97, no. 8, pp. 1438-1447, Aug. 2009, doi:10.1109/JPROC.2009.2017103, arXiv:0904.0762. ↩
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A. R. Thompson, J. M. Moran, and G. W. Swenson, Jr., Interferometry and Synthesis in Radio Astronomy, 3rd ed. (Astronomy and Astrophysics Library). Cham, Switzerland: Springer, 2017, doi:10.1007/978-3-319-44431-4. ↩ ↩2 ↩3
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L. Cruz et al., BLADE, GitHub. github.com/luigifcruz/blade ↩