Sun-induced fluorescence (SIF) retrieved from satellite measurements has been widely used as proxy for chlorophyll-a concentration and as indicator of phytoplankton physiological status in oceans. The practical use of this naturally occurring light signal in environmental research is, however, under-exploited, particularly in research focusing on optically complex waters such as inland and coastal waters. In this study, we investigated methodological and knowledge gaps in remote sensing of chlorophyll-a SIF in optically complex waters by reviewing the theory behind SIF occurrence, the availability of existing and upcoming instrumentation, the availability of SIF retrieval schemes, and the applications for aquatic research.

Starting with an overview of factors that influence SIF leaving the water body, we further investigated available and upcoming observational capacity by in situ, airborne and satellite sensors. We discuss requirements for spatial, spectral, temporal, and radiometric resolution of observing systems in the context of SIF dynamics. We assessed viable retrieval techniques able to disentangle SIF from non-SIF contribution to the upwelling radiance, ranging from the established multispectral Fluorescence Line Height algorithm (FLH) approach to hyperspectral approaches including model inversion, spectral fitting methods and machine learning regression procedures. Finally, we provide an overview of applications, which could potentially benefit from improved SIF emission estimates such as biomass estimation, algal bloom investigation and primary productivity modelling.

从卫星测量中获得的太阳诱导荧光（SIF）已被广泛用作叶绿素（a）浓度的代表，并作为海洋浮游植物生理状态的指标。但是，这种天然存在的光信号在环境研究中的实际应用还没有得到充分利用，特别是在研究光学复杂水域（如内陆和沿海水域）的研究中。在这项研究中，我们研究了叶绿素的遥感方法和知识差距一个通过审查背后SIF发生，现有的和即将到来的仪器，SIF检索方案的可用性的可用性和水生应用的理论光学复杂水域SIF研究。

从影响SIF离开水体的因素的概述开始，我们通过原位，机载和卫星传感器进一步研究了可用的和即将出现的观测能力。我们讨论了在SIF动力学情况下对观测系统的空间，光谱，时间和辐射分辨率的要求。我们评估了可行的检索技术，能够将SIF与非SIF对上升流辐射的影响区分开，从已建立的多光谱荧光线高度算法（FLH）方法到高光谱方法，包括模型反演，光谱拟合方法和机器学习回归程序。最后，我们概述了应用程序，这些应用程序可能会受益于改进的SIF排放估算，例如生物量估算，