Fluorescence LIDAR remote sensing of oils: merging spectral and time-decay measurements

In this paper we present hyperspectral and time resolved laser induced fluorescence spectra of oil slicks remotely sensed by means of a new fluorescence LIDAR prototype. The sensor provides both sub-nanometric spectral resolution and sub-nanosecond time resolution. The fluorescence induction is achieved by means of a frequency-tripled pulsed Nd:YAG laser @355 nm. The light is collect by a 250-mm diameter telescope and the fluorescence spectra are measured by a spectrometer and a 512-spectral channels gateable intensified CCD camera. The temporal resolution is achieved by sequentially delaying the gating time to obtain fluorescence data, which are resolved both in the spectral and temporal domains. Measurements were performed in the lab on three artificial 100-mu m thick oil films at a distance of 10 m. The oils were a crude oil and two different types of diesel fuel.