Scalable platform for adaptive optics real-time control, part 1: concept, architecture, and validation

Abstract

We demonstrate an architecture for adaptive optics (AO) control based on field programmable gate arrays (FPGAs), making active use of their configurable parallel processing capability. The unique capabilities of scalable platform for adaptive optics real-time control (SPARC) are demonstrated through an implementation on an off-the-shelf inexpensive Xilinx VC-709 development board. The architecture makes SPARC a generic and powerful real-time control kernel for a broad spectrum of AO scenarios. SPARC is scalable across different numbers of subapertures and pixels per subaperture. The overall concept, objectives, architecture, validation, and results from simulation as well as hardware tests are presented here. For Shack–Hartmann wavefront sensors, the total AO reconstruction time ranges from a median of 39.4 μs (11 × 11 subapertures) to 1.283 ms (50 × 50 subapertures) on the development board. For large wavefront sensors, the latency is dominated by access time (∼1 ms) of the standard dual data rate memory available on the board. This paper is divided into two parts. Part 1 is targeted at astronomers interested in the capability of the current hardware. Part 2 explains the FPGA implementation of the wavefront processing unit, the reconstruction algorithm, and the hardware interfaces of the platform. Part 2 mainly targets the embedded developers interested in the hardware implementation of SPARC.