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Subject: Marine Geospatial Ecology Tools (MGET) help

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From: "Jason Roberts" <>
To: "'Teja Arief'" <>
Cc: <>
Subject: RE: [mget-help] MGET to read net primary productivity data
Date: Fri, 31 Dec 2010 11:19:41 -0500

Dear Teja,

 

I’m glad you have used MGET successfully with ocean color and Aviso data. I have used it successfully with the Oregon State Ocean Productivity data before. If you can give me some more details about what file you want to convert and what parameters you have tried, I can explain what you need to do to fix it.

 

To make sure it still works, I prepared an example for you using the Standard VGPM 1080 by 2160 Monthly MODIS files (http://orca.science.oregonstate.edu/1080.by.2160.monthly.hdf.vgpm.m.chl.m.sst4.php). I scrolled down to the bottom and downloaded the last file, 2010152. Then I converted it with Convert SDS in HDF to ArcGIS Raster using these parameters:

 

HDF file = C:\Temp\vgpm.2010152.hdf.gz

ArcGIS raster = C:\Temp\vgpm.2010152.img

SDS name = npp

X coordinate = -180

Y coordinate = -90

Cell size = 0.166666666666667

NODATA value = -9999

 

Post-conversion processing:

Define coordinate system: GCS_WGS_1984 (you have to select it through the dialog boxes)

Build pyramids: yes

 

If you are having trouble with the spatial reference, one possibility is that your cell size is not correct. The Ocean Productivity data use larger cell sizes than the NASA Ocean Color datasets. For example, although NASA publishes MODIS chl-a data at 1/24 degree resolution (about 4.6 km at the equator), Oregon State publishes the productivity data at 1/12 and 1/6 degree resolution. If you try to convert the Oregon State files using the cell size for the NASA data, the resulting rasters will be too small.

 

Happy New Year,

 

Jason

 

From: Teja Arief [mailto:]
Sent: Thursday, December 30, 2010 11:01 PM
To:
Subject: [mget-help] MGET to read net primary productivity data

 

Dear Dr. Roberts

My name is Teja, and I was a MGET user. MGET is very powerfull and useful toolbox for my works, particularly on processing ocean color and aviso data.

I have a question about ability of MGET to process net primary productivity data (http://www.science.oregonstate.edu/ocean.productivity/). It seems the data format  is different from HDF-SMI -oceancolor data. Usually I use Convert SDS in HDF to ArcGIS Raster to read HDF-SMI-oceancolor data, but when I apply to npp-oregon data it didn't work. The value of npp data is could be read using MGET, but the spatial references doesn't work well. I use the same method as to open oceancolor data.

Your help and suggestion are really appreciated.

Warm regards
Teja

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