shows the reflectance spectra of four different aquatic macrophyte
communities: emergent perennial common reed, Phragmites
australis; floating leaved lotus (Nelumbo nucifera) and water chestnut
(Trapa natans); submerged rooted sago pondweed (Potamogeton
pectinatus) and free floating submerged coontail (Ceratophyllum
demersum); and submerged algae chara (Chara spp.). The reflectance
spectra of those communities were all measured above water. The
inset graph in Fig. 2 shows the surface reflectance of the submerged species
(coontail and sago in purple, and algae in pink) when submersed
under 1 m of water with CHL concentration 0.8 mg m−3, TSM concentration
0.7 g m−3, and CDOM(440) absorption 0.2 m−1. As the water
column depth over submerged vegetation increases, the influence of
the absorbing and scattering properties of the water column increases,
changing the submerged vegetation signal