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Full-Text Articles in Life Sciences

Impacts Of A Recurrent Resuspension Event And Variable Phytoplankton Community Composition On Remote Sensing Reflectance, Trisha Bergmann, Gary Fahnenstiel, Steven Lohrenz, David Millie, Oscar Schofield May 2004

Impacts Of A Recurrent Resuspension Event And Variable Phytoplankton Community Composition On Remote Sensing Reflectance, Trisha Bergmann, Gary Fahnenstiel, Steven Lohrenz, David Millie, Oscar Schofield

Faculty Publications

In order to characterize the impact of turbidity plumes on optical and biological dynamics, a suite of environmental parameters were measured in southern Lake Michigan during the springtime recurrent sediment plume. In-water measurements of inherent optical properties (IOPs) were entered into the Hydrolight 4.2 radiative transfer model and the output was compared with measured apparent optical properties (AOPs) across a wide range of optical conditions. Hydrolight output and measured underwater light fields were then used to clarify the effects of the sediment plume on primary production, phytoplankton community composition, and nearshore remote sensing ocean color algorithms. Our results show that …


Narrow-Band And Derivative-Based Vegetation Indices For Hyperspectral Data, Kelly Robert Thorp, Lei Tian, Haibo Yao, Lie Tang Jan 2004

Narrow-Band And Derivative-Based Vegetation Indices For Hyperspectral Data, Kelly Robert Thorp, Lei Tian, Haibo Yao, Lie Tang

Lie Tang

Hyperspectral remote sensing imagery was collected over a soybean field in central Illinois in mid-June 2001 before canopy closure. Estimates of percent vegetation cover were generated through the processing of RGB (red, green, blue) digital images collected on the ground with an automated crop mapping system. A comparative study was completed to test the ability of broad-band, narrow-band, and derivative-based vegetation indices to predict percent soybean cover at levels less than 70%. Though remote sensing imagery is commonly analyzed using reference data collected at random points over a scene of interest, the analysis of the hyperspectral imagery in this research …


Correlation Between Atmospheric Co2 Concentration And Vegetation Greenness In North America: Co2 Fertilization Effect, C. Lim, Menas Kafatos, P. Megonigal Jan 2004

Correlation Between Atmospheric Co2 Concentration And Vegetation Greenness In North America: Co2 Fertilization Effect, C. Lim, Menas Kafatos, P. Megonigal

Mathematics, Physics, and Computer Science Faculty Articles and Research

The possibility that rising atmospheric CO2 concentrations are influencing plant growth in contemporary ecosystems has received little attention, and the studies that exist have been done on a small spatial scale. We correlated the monthly rate of relative change in normalized differenced vegetation index (NDVI) from advanced very high resolution radiometer (AVHRR) data to the rate of change in atmospheric CO2 concentration during the natural vegetation growing season for evidence of a possible CO2 fertilization effect on vegetation development. The study addressed seasonal and annual patterns in spatially averaged NDVI for 3 different ecological regions in North America from 1982 …