Real Time HABs Mapping Using NASA Glenn Hyperspectral Imager

Area of Science:

• Environmental Monitoring
• Remote Sensing
• Water Quality Assessment

Background:

• Harmful algal blooms (HABs) pose a significant threat to aquatic ecosystems and human health.
• Traditional monitoring methods often lack the spatial and temporal resolution needed for effective HAB management.
• Space-based remote sensing offers broad coverage but can be limited by cloud cover and revisit times.

Purpose of the Study:

• To assess the utility of an airborne hyperspectral imaging system (HSI) for near-real-time monitoring of harmful algal blooms.
• To evaluate a vicarious correction approach for generating high-quality reflectance data from HSI radiance measurements.
• To demonstrate the advantages of airborne HSI over space-based platforms for water quality monitoring.

Main Methods:

• Deployed NASA's airborne HSI system from 2015-2017 over Lake Erie and the Ohio River.
• Implemented a vicarious correction method using a spectrally characterized asphalt parking lot as a target.
• Converted radiance data to reflectance data for HAB monitoring using existing algorithms.

Main Results:

• Achieved near-real-time (within 24 hours) water quality products.
• Demonstrated the effectiveness of the vicarious correction method for accurate reflectance data.
• Highlighted the flexibility of airborne HSI, including operation under cloud cover and on-demand flight path adjustments.
• Showcased high spatial resolution (approximately 1m) data for detecting small bloom patches and monitoring proximity to water intakes.

Conclusions:

• Airborne HSI provides a flexible and high-resolution alternative to space-based monitoring for harmful algal blooms.
• The developed vicarious correction method enables rapid and accurate water quality assessments.
• Airborne HSI serves as a valuable complementary tool for existing satellite platforms, enabling targeted monitoring and rapid response to bloom events.