Real time optical pre-detection processing of multispectral image data

An apparatus for forming a plurality of spectrally weighted values from multispectral radiation received from a pixel comprising:

• an optical system for gathering multispectral radiation from the pixel;
• a wavelength dispersing element disposed to receive the multispectral radiation gathered by said optical system for spatially disbursing said gathered radiation by wavelength into a grid of a plurality of wavelength band areas.
• a weighting filter disposed to receive radiation dispersed by said wavelength dispersing element having a plurality of pairs of first and second weighting filter elements corresponding to each of said wavelength band areas;
• a wavelength converging element disposed to receive radiation filtered by said weighting filter for spatially converging all wavelengths of radiation filtered by said first weighting filter elements to a first detector location and all wavelengths of radiation filtered by said second weighting filter elements to a second detector location;
• a plurality of first detectors, one disposed at each first detector location, each first detector for forming a first electrical signal corresponding to the intensity of radiation at said corresponding first detector location;
• a plurality of second detectors, one disposed at each second detector location, each second detector for forming a second electrical signal corresponding to the intensity of radiation at said corresponding second detector location;
• and
• a plurality of difference devices each connected to corresponding first and second detectors, each difference device for forming a difference signal between said corresponding first and second electrical signals, said difference signals being the spectrally weighted values.

An apparatus for forming a spectrally weighted value from multispectral radiation received from each of a plurality of pixels comprising:

• an optical system for gathering multispectral radiation from each of said plurality of pixels into a linear array;
• a wavelength dispersing element disposed to received the multispectral radiation gathered by said optical system for spatially dispersing said gathered radiation by wavelength for each of said plurality of pixels into a plurality of wavelength band areas;
• a weighting filter disposed to receive radiation dispersed by said wavelength dispersing element having first and second weighting filter elements corresponding to each of said wavelength band areas;
• a wavelength converging element disposed to receive radiation filtered by said weighting filter for spatially converging all wavelengths of radiation filtered by each of said first weighting filter elements to a corresponding first detector location and all wavelengths of radiation filtered by each of said second weighting filter elements to a corresponding second detector location;
• a plurality of first detectors, one disposed at each first detector location, each first detector for forming a first electrical signal corresponding to the intensity of radiation at said corresponding first detector location;
• a plurality of second detectors, one disposed at each second detector location, each second detector for forming a second electrical signals corresponding to the intensity of radiation at said corresponding second detector location;
• and
• a plurality of difference devices connected to corresponding first and second detectors, each difference device for forming a difference signal between corresponding first and second electrical signals said difference signals being the spectrally weighted value.