1. A method of combining registered high spatial resolution panchromatic imagery and lower spatial resolution multispectral imagery existing in a plurality of spectral bands to synthesize higher spatial resolution of the multispectral imagery as an ensemble of the plurality of spectral bands, said method comprising, collecting high spatial resolution panchromatic imagery, collecting lower spatial resolution multispectral imagery existing in a plurality of spectral bands, and initializing the collected imagery to produce a global model relating spatially overlapping multispectral and panchromatic intensities by determining the linear radiometric relationship between the panchromatic imagery and the multispectral imagery bands as an ensemble of the plurality of spectral bands, said initializing compromising, generating uniformly distributed registered panchromatic and multispectral image samples from the collected panchromatic imagery and the collected multispectral imagery, determining color weights from the generated panchromatic and multispectral image samples in the form of a weighting vector which is normal to a panchromatic hyperplane containing multispectral imagery intensity vectors and modulated by panchromatic intensities, and then pixel by pixel panchromatic sharpening processing the multispectral imagery in said ensemble by using the determined color weights and associated panchromatic intensity to produce a sharpened product, said pixel by pixel processing comprising, spatially resampling the collected multispectral image intensities to panchromatic imagery resolution, projecting the resampled multispectral image intensities onto said hyperplane to adjust the intensities of the resampled multispectral imagery to the closest global model intensity contained in said hyperplane and to thereby produce a synthesized multispectral imagery which is sharpened to have substantially the spatial resolution of the panchromatic imagery, and wherein sharpening the imagery in the plurality of spectral bands as an ensemble rather than sharpening the imagery in the plurality of spectral bands sequentially band by band reduces the amount of processing required and reduces the time required for said sharpening of the multispectral imagery.