MERIS Autonomous Processing System


Brief description


The system is designed for automatic download, processing and visualization of MERIS ocean color data. MERIS is an optical sensor installed onboard of the ESA satellite ENVISAT. The MERIS images in N1 format are provided by ESA on a daily basis in a rolling archive.The developed system automatically downloads swaths of images containing the North Sea region. These images are further geometrically corrected by the Brokmann-Consult software BEAM/Mapproj. Geometrically corrected images are then processed by a bio-optical semi-analytical algorithm developed at NIERSC. The algorithm retrieves concentrations of chlorophyll, colored dissolved organic matter and total suspended matter. It utilizes the hydro-optical model developed at NERSC for the North Sea on the basis of in situ bio-chemical and optical measurements. The results of processing are merged so that daily, weekly and monthly averaged data are available. The fields of retrieved concentrations are visualized along with standard MERIS products and some additional products as JPG files. The web-page (www.nersc.no/~antonk) is created for dissemination of the developed images via the WWW.

How to Use


The web-page presents images in a column-row-wise order. Each row corresponds for one day of the North Sea satellite observation. Each column contains products of the same type. By default only the product called "chl (Case II) ESA" is visualized for the current and previous 15 days. The interface allow user to visualize all other products and to view data for other days and for another period. Note that in the left part of the table floating seven days averages are displayed. Daily images are displayed in the right part of the table.
EXAMPLE:
In order to view "tsm ESA" and "tsm NERSC?NIERSC" products for the 5 days period 25.05.2005 - 30.05.2005 it is necessary to specify the Year = "2005", the Month = "05", the LAST day of the period: "Day" = 30 and the period length "Period – 5 days". Then check the necessary products checkboxes and click on the show button .

Displayed Products

The table describes the names of the displayed products and the names of the files.
Products name Product Algorithm File key name
chl case 1 ESA Clorophyll-a ESA (case I) algal_1
chl case II ESA Clorophyll-a ESA (case 2) algal_2
tsm ESA Total Suspended Matter ESA total_susp
cdom ESA Colored Dissolved Organic Matter ESA yellow_subs
chl NERSC/NIERSC Clorophyll-a NERSC/NIERSC lmchl
tsm NERSC/NIERSC Total Suspended Matter NERSC/NIERSC lmsm
cdom NERSC/NIERSC Colored Dissolved Organic Matter NERSC/NIERSC lmdoc
mse NERSC/NIERSC Mean square error (difference between measured and reconstructed Rrsw spectra, also used as retrieval quality estimation) NERSC/NIERSC mse
counts NERSC/NIERSC Number of pixels used in averaging NERSC/NIERSC counts
RGBNERSC/NIERSC Pseudo color images constructed from 2nd (442 nm), 5th (559 nm) and 6th (619) MERIS bands. NERSC/NIERSC rgb