Whether you consider the accelerated glacial melt caused by global warming, the eutrophication of regional lakes and reservoirs from urban and agricultural runoff, or the loss of wetlands through urban expansion and climate change, the impact of human activities on the quality of water resources is pervasive. It is necessary to study the importance of these effects and the resulting vulnerability of the earth’s entire ecosystem.
Utilizing a combination of field and satellite remote sensing methods, oceanographers, limnologists, and other environmental and marine researchers studying these effects can perform thorough assessments of these vast target areas. Satellites, such as NASA’s Landsat, produce imagery useful for lake remote sensing and other inland water bodies, as well as coastal mapping. Image data from NASA’s MODIS and NOAA’s AVHRR is used for ocean remote sensing to monitor sea surface temperatures, chlorophyll levels, and surface currents.
Extraction of historical and current water quality data via satellite images, combined with field data acquisition efforts facilitates the development of comprehensive dataset references which are useful in the evaluation and trending of changes in water quality over time. The ability to accurately perform field reflectance and radiometric measurements, without reliance on a laboratory, is critical to all of these applications. The ASD FieldSpec® line of spectroradiometers offers multiple configuration options for water body analysis. The ASD systems use a flexible fiber optic cable with several different accessories, giving researchers a variety of options for different water-related applications. Providing a level of instrument portability that only ASD technology can, the FieldSpec® spectroradiometers offer the ability to cover sites on some of the most remote regions of the Earth.
High spectral resolution observations of bodies of water have led to a better understanding of natural water body absorption and transmission properties, phytoplankton ecologies, algae blooms, and heat flow layering. By analyzing the water-reflected radiance, researchers can infer the water-leaving radiance values without taking in-water measurements. This allows researchers to develop improved algorithms for analysis of satellite imagery of water bodies. In-situ measurements can be used for interpretation and field validation of satellite imagery and other direct applications, such as determining underwater visibility and military laser limits, modeling plankton blooms, monitoring sediment discharge, and developing climate models.
Below are some examples of oceanography and limnology research by scientists using ASD instrumentation.
McMurdo LTER: Using narrow band spectroradiometry to assess algal and moss communities in a dry valley stream. Antarctic Journal of the United States--Review 1994
Ocean View
The Selection of Narrow Wavebands for Optimizing Water Quality Monitoring on the Great Miami River, Ohio using Hyperspectral Remote Sensor Data
Field campaign in July 2001 parallel to ROSIS overflights
Preliminary Mission Plan for a Puerto Rico Dust Experiment (PRIDE) for Summer 2000
Ecological risk assessment in heterogene polluted Dutch river floodplains
Southeastern Division of the Association of American Geographers, Abstracts, Lexington, Kentucky, November 2001
Remote-Sensing Technique for Determination of the Volume Absorption Coefficient of Turbid Water
Effect of Suspended Particulate and Dissolved Organic Matter on Remote Sensing of Coastal and Riverine Waters
Lake Tahoe Experiment Summary Report