Abstract: The Charge Coupled Device ("CCD"), which is an integrated circuit array sensor in "chip" form, of a pushbroom spectrographic imager is operated to achieve fast dumping of unwanted rows of charges. The chip is provided with antiblooming structure in the image area and the first row of the storage area. The rows of charges are divided into groups of several rows. The groups of interest (i.e. the active groups) and those that are not wanted (i.e. the discard groups) are so designated. The rows in each group are summed in the antiblooming structure of the storage area. The active summed rows are sequentially transferred by the chip's transport register to an output amplifier, wherein the individual charges are read out and digitized to yield signal values for collection. The discard summed rows are cleared without digitization.