Reflectance spectra of Entermorpha In the whole life cycle

Abstract

Reflectance spectra of Entermorpha were the basis of dynamically monitoring Entermorpha hazard in a large scale by remote sensing technology. Reflectance spectra of Entermorpha vary under different development periods due to great differences in their physical, chemical and biological properties. To explore the changes of reflectance spectra of Entermorpha through its whole life cycle, we collected Entermorpha from Huangwo, LianYunGang. The whole life cycle here was defined as from spore period, seedling period, maturation period, to death period. The reflectance spectra of Entermorpha in the whole life cycle were measured by ASD FieldSpec HandHeld spectrometer. Based on these reflectance spectra data, the reflectance spectra of Entermorpha during the whole life cycle were extracted by spectra morphology method. The results indicated that during the spore period, the measured reflectance spectra actually was the reflectance of sea water because the spore of Entermorpha could not identified by naked eye. During the seedling period, the peak and valley of reflectance spectra was not very obvious because of narrow length and width of Entermorpha. Weak peak and valley reflectance spectra were observed until the length reached 8 cm and the width reached 1.5 mm. During the maturation period, reflectance spectra had conspicuous peak and valley, however the whole reflectivity was very low, which was less than 0.3. During the death period, the absorption valley in the red light band, one of the reflectance spectra characteristics of Entermorph tended to decrease.