Passive remote sensing technology for mapping bull kelp (Nereocystis luetkeana): A review of techniques and regional case study
Abstract The distribution and abundance of the canopy-forming kelp Nereocystis luetkeana is of increasing concern for environmental management and conservation in coastal regions due to its importance as a foundation species. Mapping kelp forests aids in understanding their health, productivity, and response to environmental conditions. Remote sensing using satellites is an increasingly accessible tool for mapping nearshore habitats allowing for applications such as long-term monitoring and large- and small-scale surveys. This paper provides a review of passive optical remote sensing techniques for detection and mapping of floating macro-algae, and adapts these techniques for detecting Nereocystis luetkeana , demonstrating their application through a comprehensive case study, from imagery acquisition to map validation. This review with associated case study communicates to non-remote sensing experts a road map to use remote sensing technology for mapping kelp habitats.
For many years it has been assumed that nonradiative recombination plays a dominant role in determining the high temperature performance of long wavelength laser diodes. We show that this view is inconsistent with the measured temperature dependence of spontaneous emission from light emitting diodes. We conclude that net gain primarily determines the temperature sensitivity of threshold in long wavelength semiconductor lasers.