Translator Disclaimer
9 July 1998 New low-noise high-quantum-efficiency speckle imaging system
Author Affiliations +
A design for a new-concept speckle imaging system is presented. The instrument, now under construction at Rochester Institute of Technology (RIT), will be able to use any large- format scientific-grade CCD as the imager. The high quantum efficiency, low noise, and linear response of current CCDs are attractive characteristics when compared with traditional photon-counting speckle imaging systems. The RIT system consists of an optics package, placed between the telescope and the imager, that contains a piezoelectric tip-tilt mirror capable of executing a timed sequence of movements to place many speckle patterns over the active area of the CCD. The system will either (a) place a series of speckle images in a row and then use the CCD electronics to periodically shift charge toward the serial register or, if the CCD electronics do not allow, (b) have the mirror perform a serpentine step- and-scan motion over the entire CCD. When the entire CCD is full of speckle images, the chip is read out as normal. This kind of 'burst mode' speckle data collection effectively uses the large area of the CCD as a memory cache of speckle data frames, allowing large format scientific-grade CCDs that already exist at many observatories to be used efficiently and inexpensively in speckle imaging. The expected performance of the system, which is dependent on the CCD imager, is discussed. CCD speckle observations at the WIYN* 3.5-m telescope and simulation results indicate that, when used with a very low noise CCD, this system could obtain speckle data that are superior to those of even the best photon-counting cameras at the fainter magnitudes where such cameras are currently used.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Elliott P. Horch, Zoran Ninkov, and William F. van Altena "New low-noise high-quantum-efficiency speckle imaging system", Proc. SPIE 3355, Optical Astronomical Instrumentation, (9 July 1998);


Back to Top