ABSTRACT: The traditional method used in the water quality classification of Finnish lakes includes the collection of water samples from lakes and their analysis in laboratory conditions. The classification is based on statistical analysis of water quality parameter values and on expert opinion. It is possible to acquire similar information by using radiance values measured with the Earth Observing System Terra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS). In this letter, the classification accuracy with MODIS data is about 80%. Only about 0.2% of the 20 391 pixels were misclassified by two or more classes, as a four-class classification system is used.
IEEE Geoscience and Remote Sensing Letters 11/2004; · 1.56 Impact Factor
ABSTRACT: In this work we demonstrate the feasibility of imaging spectrometer for the detection of oil spills on sea ice. We show that optical spectrometer images can be used as an alternative for oil spill mapping in winter when SAR-based detection algorithms fail due to ice. By comparing high-resolution airborne spectrometer image to satellite images, we evaluate the usability of MODIS and Landsat images for oil pollution detection on ice and discuss the limitations, set by image resolution and spectral band availability. We evaluate here several spectral indices and discuss the results. We propose simple algorithms for oil detection on ice. Our study strongly suggests that an imaging spectrometer suits very well to oil detection on sea ice. However usability of satellite instruments like MODIS have serious limitations set by the image resolution and band selection. Landsat ETM has significantly better resolution and it is therefore more suitable for most typical, small-scale pollution detection, but its imaging frequency does not meet the monitoring demands
Geoscience and Remote Sensing Symposium, 2004. IGARSS '04. Proceedings. 2004 IEEE International; 10/2004
ABSTRACT: Reliable monitoring of the pelagic ecosystem has proved to be
problematic because of its high temporal and spatial heterogeneity.
Processes like algal blooms or pollution discharges are patchy, both
temporally and spatially. Consequently, they often remain unobserved
using the traditional sampling methods based on temporally sparse
sampling at a few fixed stations. Furthermore, the traditional programs
are usually unable to rapidly report of exceptional events. Monitoring
of water quality could be more effective if satellite or airborne remote
sensing is used. New optical satellite sensors with high spectral
resolution have recently been launched and more sensors will be
available in the near future. Empirical algorithms, like spectral
ratios, are widely used in the interpretation of remote sensing data.
However, these algorithms seem to have local and seasonal variability
and different algorithms are needed for coastal and inland waters
Geoscience and Remote Sensing Symposium Proceedings, 1998. IGARSS '98. 1998 IEEE International; 08/1998