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MERIS MPH processor
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MERIS MPH processor
2/16/15 8:29 PM
Hello!

I am currently trying to run rhis new version of MPH processor. I was wondering how I should determine two input values that are required (cyano max value and Chl thresh for float flag). Should I look my in situ data in order to figure this out or are these given values suitable for a standard shallow and eutrophic inland water body. I would be really thankful if one could give me some ideas how to approach these input values.

Best wishes,
Evelin
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RE: MERIS MPH processor
mph algorithm mph processor
2/18/15 1:57 PM as a reply to Evelin Kangro.
Hi Evelin

The cyanomax value refers to the maximum chlorophyll value generated from the chlrophyll algorithm over cyanobacteria blooms. I suggest using a value of 350, 500 or up to 1000 mg m-3. It is trained with values up to 500.

The Chl threshold for the floating flag refers to the value at which you deem the cyanobacteria bloom to be a "floating surface scum". A typical value for this is around 350 mg m-3 at which stage the bloom may be referred to as floating scum. Pixels identified as cyanobacteria with chlorophyll values greater than this specified value will also be assigned as floating matter and appear in the floating flag layer.

I hope that clarifies things for you?

Best wishes

Mark.
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RE: MERIS MPH processor
11/26/15 1:18 PM as a reply to Mark Matthews.
I am running the MPH algorithm and not sure if I am following the correct process since the outcome I am getting is picking up the outline (coastline pixels) of the dam (Loskop Dam in South Africa), but not the water pixels. The process I followed was:

MERIS Rayleigh Correction on MERIS L1 radiances data to generate the BRR product

MERIS MPH processor (with Cyanomax 500 and Chl threshold 350) to generate the MPH product

Could you please assist?
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RE: MERIS MPH processor
12/4/15 9:14 AM as a reply to Sukhmani Kaur Mantel.
Hi Sukhmani

The problem here is with land masking of small reservoirs. The l1 land mask flag which is the default with MERIS products is suitable only for large lakes and oceans. When running the algorithm on L1 Rayleigh corrected reflectance do not apply any land mask so that all of the pixels in the scene are processed (land and water). Then afterwards you can apply your own high resolution land mask to extract the lake pixels (e.g. using a shapefile). I think there is a way to do this even in BEAM using a polygon for instance. I can't provide a step by step solution, but at least you know what is causing your problem.

Best wishes

Mark.
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