Charge injection device boosts chances of detecting Earth-like planets near bright stars

The quest to find small, Earth-like exoplanets isn’t just a matter of pointing an exceptionally powerful telescope towards a star, as one may do to observe moons orbiting a planet. Apart from resolving images adequately in relation to the enormous distances involved, the glare from a distant sun often washes out the image of anything but the largest of planetary bodies in its vicinity. To help combat this problem, researchers at the Florida Institute of Technology (FIT) have developed a new type of astronomical camera that can detect the faint reflections of distant worlds near bright stars many millions of times better than that possible with an ordinary telescope.

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[quote=CrazyNeutrino] <a href="http://www.gizmag.com/astrophysics-exoplanets-telescope-camera-cid/42011/">Charge injection device boosts chances of detecting Earth-like planets near bright stars</a> This is where FIT's charge injection device, or CID, comes in. A CID is basically a photosensitive semiconductor chip able to convert optical signals in the 185 nm to 1100 nm range to electronic charges that can be displayed as a video signal or further processed and enhanced via computer. To do this, every capacitive pixel in the CID array is able to be individually addressed using electronic indexing of the electrodes connected to the rows and columns. As such, when fitted to an optical telescope, the pixels in the CID that receive large amounts of light are acknowledged very quickly and idled down, while the pixels receiving faint amounts of light are allowed to continue gathering light for a longer time. In other words, the various pixels in the CID array act in the opposite way expected of an optical detection array by responding least to bright incoming light and most to faint light. This, then, effectively means the device acts like it has semi-transparent masked areas that prevent the entire observed area being washed out. Different to Charge Coupled Device (CCD) cameras often used in astronomical telescopes – such as in the Pan-STARRS asteroid and comet tracker – that move collected charge out of the pixel when it is read (which then erases the image stored on the sensor), the charge stays within each pixel in the CID array. Converting the images captured in a CID involves detecting the displacement current between individual pixels, which is then amplified and converted to a voltage, and then forms part of a composite video or digitized signal. To clear the array for capturing the next image, the row and column electrodes connecting the pixels are briefly switched to ground thereby dissipating, or "injecting" the charge into the underlying semiconductor substrate. [/quote] > the charge stays within each pixel in the CID array Good. No overfilling or bleeding. > detecting the displacement current between individual pixels Bad. Can't get accuracy that way. > Imaging of Sirius Excellent. Does anyone understand this device? eg. understand the slideshow from page 23 of "Charge Coupled Device and Charge Injection Device Technology":https://people.rit.edu/lffeee/lec_CCD.pdf "Each pixel consists of a pair of MOS capacitors. The two capacitors run perpendicularly to each other." Could it be that the pixels can be read by energising each row in turn to get a readout on every column that gives the capacitance between the energised row and that column? Nah, still don't get it, how do you non-destructively read a capacitance?