dead-times


This form allows you to calculate the dead-time of an ULTRACAM exposure. The default parameters are those of a Marconi CCD47-20 chip used in conjunction with an SDSU controller. The following assumptions/limitations have been made/imposed:
  1. The number of rows in the masked region is equal to the number of rows in the imaging region and both regions are square
  2. All windows are assumed to be square.
  3. No more than 2 windows are allowed.
  4. If one window is selected, it is assumed that it is aligned with one edge along the border of the imaging/masked region. It is further assumed that each of the two readout channels reads out half a window.
  5. If two windows are selected, it is assumed that they are aligned with one of their edges along the border of the imaging/masked region and that they are maximally separated along this border. As a result, it is further assumed that each of the two readout channels reads out one of the windows.
  6. The window size must be an integer multiple of the binning factor.
  7. It is assumed that binning does not reduce the number of rows which have to be clocked vertically or the number of columns which have to be shifted along the serial register. Binning does, however, reduce the total number of rows which are clocked into the serial register and the total number of pixels which have to be read out.





number of rows in masked region
number of windows
window size pixels on a side
binning factor pixels
vertical clocking speed µseconds/row
serial register clocking speed µseconds/pixel
readout speed µseconds/pixel/readout channel
exposure time seconds