Ground-based infrared observations are often limited by atmospheric absorption and emission. Space-based instruments avoid this, but introduce unique technical challenges. We present the design of a flexible, compact, and cost-effective detector controller for space, based on commercial off-the-shelf components. Its architecture provides up to 50 configurable clock sequences and 16 biases, 32 16-bit video channels and several genera lpurpose ports. This allows for full control of CMOS detectors including Leonardo ‘SAPHIRA’ avalanche photodiode arrays (APD) which represent current state of the art in low-noise infrared imaging.
The Leonardo SAPHIRA is a HgCdTe linear avalanche photodiode array enabling high frame rate, high sensitivity, low noise, and low dark current imaging at near-infrared wavelengths. The ANU utilised the Leonardo SAPHIRA to develop a high cadence “Lucky Imager” which was successfully tested on sky at Siding Spring Observatory. The cryogenic electronics and cryostat were designed and built by the ANU. The cryostat was cooled with a compact Stirling cycle cryocooler with active vibration damping. Various detector control systems were tested, including an ESO 'NGC' system and also a 32 channel ARC SDSU Series III. Images were ultimately captured at a windowed frame rate of 2.2 kHz with the ESO NGC controller.
‘Emu’ is a compact wide-field photometer destined for a 6-month mission on the exterior of the International Space Station (ISS), commencing in 2021. Emu will undertake a sky survey in the 1.4 μm ‘water band’, as a method of estimating oxygen abundance in the atmospheres of cool stars down to a magnitude of mAB≈13 (H-band).