Senior Theses 2005
Lance Mosher (2005). Analysis of time-resolved backscatter
intensity waveforms for determination of backscatter coefficients
in Tampa Bay
Faculty Advisors: Ann Cox, Laura Wetzel
The greater Tampa Bay area is developing rapidly, which may be placing increasing stress on the marine environment. The human impact on Tampa Bay may be monitored by analyzing the optical properties of the water, such as backscatter, which will reflect the state of the environment. In this study, backscatter intensity waveforms from the National Aeronautical Space Administration's Experimental Advanced Airborne Research Lidar (EAARL) are analyzed to determine the backscatter coefficient, which relates to water quality and suspended sediments. An uncalibrated measurement is compared with in situ backscatter data collected coincidentally with the lidar survey. No correlation between the remote sensing backscatter (RSB) and in situ backscatter (ISB) was found for the first three surveys. This was due to insignificant change in backscatter properties for the first two days and possible interference from the sea floor on the third day. On the final mission, a correlation with an R2value of 0.58 was observed, suggesting a correlation between RSB and ISB.
Observation of RSB measurements show that the backscatter tended to decrease with distance from shore, but decreased more slowly in the Alafia River area than near Feather Sound: Since both regions have similar land development, it is likely that the AlafiaRiver has a higher flux of suspended materials from land to sea. It is also likely that, due to increased backscatter, sea grasses near the Alafia River receive less light than near Feather Sound and therefore have higher photosynthetic stress. However, to validate the RSB result and solidify these claims, a more robust ground truthing survey should be conducted and, an improved RSB model should be developed.