Background
Current Processing/Products
Select References
Contacts


Background

Water quality mapping is one of several services being developed by Noetix Research Inc. under the Water Resource Development Project (WRDP) funded in part by the Canadian Space Agency (CSA). Other services include lake and river ice, water quantity and snow water equivalance (SWE).

Earth Observation (EO) data has been used for some to time map total suspended solids (TSS) and algae blooms. Currently Mike Stainton (Department of Fisheries and Oceans, Winnipeg) together with Greg McCullough are doing extensive research on developing algorithms for TSS and algae using MODIS and MERIS data.

This web site provides weekly images of TSS and algae blooms using NOAA AVHRR data. Water quality algorithm for this sensor was developed based on work by McCullough et al., 2001. The main benefit of using AVHRR data is that daily imagery dates back to ~1985, therefore historical trends in water quality can therefore be examined.

The information provided at this site is free of charge during the development and demonstration phases (2005-2006).


Current Processing/Products

Noetix Research has implemented an end to end processing stream to produce a TSS and an Algae Bloom Detection product. The EODM software developed by CCRS (Latifovic et al., 2005) is being used to preprocess the AVHRR data. Significant radiometric improvements have been realized using this software, especially as it relates to the surface reflectance products. This is largely due to using gridded atmospheric parameters near coincident with the satellite overpass to correct for spatially varying atmospheric effects (Figure 1). The need for dark object subtraction (DOS) is therefore largely eliminated and hence the errors associated with this technique.



Figure 1. Example of gridded atmospheric data used to improve at surface reflectance.

The general processing scheme is outlined in Figure 2. Note, the shoreline has been buffered 2 km to minimize potential elevation of apparent lake reflectance by radiance "drift" from adjacent land pixels. Image statistics are extracted over standard targets (oligotrophic lakes) to check that the surface reflectance products are correct.



Figure 2. Generalized processing stream to generate water quality products from AVHRR data.


Select References

McCullough, Greg, Klaus Hochheim and Paul Cooley (2001). Retrospective study of suspended sediment patterns on Lake Winnipeg using NOAA AVHRR satellite imagery. Contract Report to the Canada Department of Fisheries and Oceans, Winnipeg, Canada. Pp. 96.

Rasim Latifovic, Alexander Trishchenko, Ji Chen, Bill Park, Konstantin Khlopenkov, Richard Fernades, Darren Pouliot, and Calin Ungureanu (2005). Generating historical satellite data records for Canada to support climate change studies. Canadian Journal of Remote Sensing. (Submitted).


Contacts

For further details:

Klaus Hochheim, PhD.
Noetix Research Inc.,
(613) 236-1555
khochheim@noetix.on.ca