• Home
• Environments
  • Marine
  • Terrestrial
  • Atmospheric
• Interface
  • Text
  • Graphic
• Resources
  • What is remote sensing
  • Fundamentals
  • Time and cost
  • Technical info
• Help
• Contacts

• Main page
• Pre-processing
  • Introduction
  • Image acquisition
  • When to correct
  • Correction types
  • Atmospheric correction
  • Relative atmospheric correction
  • Relative atmospheric correction
  • Physics-based correction
  • Sun glint correction
  • Air water interface correction
  • Depth correction
  • Geometric corrections
  • When to correct
  • Masking
• Field data collection
  • Introduction
  • Benthic sampling
  • Benthic field data sources
  • Evaluating field survey techniques
  • Georeferenced photo transects
  • Transects - photo analysis
  • Transect output
  • Transects - required equipment
  • Snorkel vs AUV surveys
  • Examples
  • Advantages and disadvantages
  • AUV example with validation
  • Spectral libraries
  • Example spectra
  • Optical water properties
  • Bathymetry
  • Control points
  • Features mapping
• Mapping approaches
  • Introduction
  • Manual delineation
  • Object based analysis
  • Supervised classification
  • Unsupervised classification
  • Inverse modelling
  • Physics-based approach
  • Regression analysis
• Change and trends
  • Introduction
  • About
  • Image requirements
  • Mapping change
  • Trend detection
  • Example time series
  • Variations in coastal water clarity
  • Variations in benthic-microalgae mats
  • Variations in Sargassum cover
  • Changes due to cyclone impact
  • Example change maps
  • Seagrass example
  • Sea surface temperature example
  • Coral bleaching example
  • Cyclone, coral bleaching, and coral recovery
• Delivery
  • Introduction
  • Post classification
  • Refinements and smoothing operations
  • Stratification and post-classification sorting
  • Error assessment
  • Sampling design
  • Sampling unit size
  • Number of samples
  • Sampling scheme
  • Selecting a reference data set
  • Reference data example
  • Derivation of error or contingency matrix
  • Category level accuracy
  • Map level accuracy
  • Quantitative image products
  • Interpreting mapping accuracy
  • Interpreting mapping accuracy
  • Interpreting mapping accuracy
  • Interpreting mapping accuracy
  • Final map creation

Effect of the air-water interface:

• light changes direction at air - water interface (refraction)
• varies according to wavelength
• correction can be achieved by:
  • literature values (Andrefouet et al 2001)
  • modelled (Kirk 1994, Pope and Fry )

correction types

References:

Andréfouët, S., F. Muller-Karger, E. J. Hochberg, C. Hu and K. L. Carder (2001). "Change detection in shallow coral reef environments using Landsat 7 ETM+ data." Remote Sensing of Environment 79: 150 - 162.

Kirk, J. T. O. (1994). Light & Photosynthesis in Aquatic Ecosystems, 2nd ed. New York, Cambridge University Press: 509.

Pope, R. M. and E. S. Fry (1997). "Absorption spectrum (380-700 nm) of pure water. 2. Integrating cavity measurements." Applied Optics 36(33): 8710-8723.