Dark noise and read-out noise are the two major sources of noise in CCD cameras. Although great improvements have been made over the past few years in the reduction of CCD dark noise at room temperature, cooling the chip further reduces the noise tenfold per 20 C decrease. The tutorial initializes by displaying a square wave signal that represents the ideal output from a CCD circuit. To view the effect of various noise sources on the output signal, make a new selection from the Choose A Source pull-down menu.
Noise sources vary in digital cameras.
The cost of going faster is more noise and hence, more uncertainty in the voltage determination and lower number of bits of resolution. Instead of reading the stored charge from the entire CCD through one output amplifier, the sensor is divided into four or eight sections each of which has its own amplifier. The image is read out in parts and then stitched together in software at rates of several frames per second. The required speed and associated noise of each amplifier are reduced accordingly. Authors Kenneth R. Spring - Scientific Consultant, Lusby, Maryland, 20657.