We present a summary of activity at the Cambridge Optical Aperture Synthesis Telescope (COAST) group
during the period 2004-2006. Our main program has focused on technical design and prototyping for future
facility arrays such as the VLTI and Magdalena Ridge Observatory Interferometer, but with a small parallel
effort of focused astronomical observations with COAST, in particular multi-wavelength studies of supergiants.
We report on progress on these and other technical areas over the past 2 years.
We describe the design of a new IR camera for the Cambridge Optical Aperture Synthesis Telescope that has been designed both to increase our science productivity at COAST and to prototype novel hardware architectures for the Magdalena Ridge Observatory Interferometer IR detector systems. The new camera uses a Rockwell HAWAII sensor in place of the NICMOS device from our previous camera and will be able to sample the temporal fringe patterns from the four outputs of the COAST infrared beam-combiner at frame rates up to 10 kHz. The use of non-destructive multiple reads should allow an effective read noise of 3 electrons to be attained with this chip. The camera controller uses a PulseBlaster FPGA card to generate the timing signals: the advantages of this are flexibility, ease of use, and rapid reconfiguration of the clocking scheme. The new system should improve the IR sensitivity of COAST by around 2 magnitudes. We detail the design of the hardware and the associated software.