Novel techniques for the efficient reduction of data generated by charge-coupled device detectors

With the increasingly widespread employment of charge-coupled devices as detectors, there is much interest in methods of processing the data which they produce. Taking the reflection grating spectrometer instrument on the European Space Agency’s recently launched X-ray MultiMirror Mission spacecraft as an example, some novel techniques for removing unwanted data are explored. Entirely independent of compression techniques which may be employed elsewhere in the same system, deletion of unwanted data as close as possible to the source can be desirable to save subsequent processor time, or communications bandwidth—both quantities that are typically in short supply in the spacecraft case. This article sets out the general case for choosing to remove unwanted pixel data close to the source, considers the implications of this on the overall quantity of data, and then examines some methods for reducing the data volume.