  This paper presents SAMSON, a Spectral Absorption-fluorescence Microscopy
System for ON-site-imaging of algae within a water sample. Designed to be
portable and low-cost for on-site use, the optical sub-system of SAMSON
consists of a mixture of low-cost optics and electronics, designed specifically
to capture both fluorescent and absorption responses from a water sample. The
graphical user interface (GUI) sub-system of SAMSON was designed to enable
flexible visualisation of algae in the water sample in real-time, with the
ability to perform fine-grained exposure control and illumination wavelength
selection. We demonstrate SAMSON's capabilities by equipping the system with
two fluorescent illumination sources and seven absorption illumination sources
to enable the capture of multispectral data from six different algae species
(three from the Cyanophyta phylum (blue-green algae) and three from the
Chlorophyta phylum (green algae)). The key benefit of SAMSON is the ability to
perform rapid acquisition of fluorescence and absorption data at different
wavelengths and magnification levels, thus opening the door for machine
learning methods to automatically identify and enumerate different algae in
water samples using this rich wealth of data.
