Prospect for HEW Applications of Multivariate Statistical Analysis in Microscopy and Spectroscopy
Multivariate Statistical Analysis has been developed in order to process large data sets and to extract from them the significant information.It has been introduced in electron microscopy in order to process image series of macromolecules and to classify individual images into several subsets of the series. This kind of series can be considered as a spatial series.In fact, electron microscopy and spectroscopy are using more and more image sequences in order to be able to access more precisely the content of the object studied. Among the different types of sequences which are already used and which will be used more extensively in the near future, one can mention : —spatial series (several slightly different objects, whose images are to be classified and combined ; or several microanalytical spectra recorded at different places of the object).—time series : in order to study changes induced in the object, one has to record successive images or spectra.—series in energy : one possibility to study the behavior of a specimen is to vary the accelerating voltage, to record several images or spectra and process the whole data set. Another exemple of series in energy is given by energy loss elemental mapping (or Auger elemental mapping) where several energy filtered images must be recorded (below and above the edge of interest) in order to get a “true” elemental map.—more “exotic” series can also be obtained, for instance series obtained by varying the spot size in MEB, series obtained with different configured detectors in STEM...