MCD19A2 incorrect tile size

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alexkrart
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MCD19A2 incorrect tile size

by alexkrart » Mon Feb 26, 2024 3:11 pm America/New_York

I am trying to analyze AOD 0.55 on 1km grid for a specific area using Python and GDAL library. To do that I need to be able to convert latitude and longitude coordinates into pixel coordinates.

In User Guide for MCD19A2 it is said that each tile has a size of 1200 x 1200 km^2. However, I have found that at least tile h18v4 has another size, moreover, it is not square.
h18v4 polygon coordinates are:
"39.8144151 13.0379033 49.9989722 15.5723927 50.006969 -0.0086748 39.8197706 0.0001314 39.8144151 13.0379033"
The distance between bottom-left and top-left points is 1132 km. The distance between bottom-right and top-right points is 1149 km. Photos are attached.
 
So, what is the way to convert latitude and longitude coordinates into pixel coordinates?

LINKS
1) User Guide
https://lpdaac.usgs.gov/documents/1500/MCD19_User_Guide_V61.pdf
2) Earthdata Search to find tile's polygon
https://search.earthdata.nasa.gov/search?fi=MODIS&portal=idn
Attachments
right_side.jpg
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left_side.jpg
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LP DAAC - dgolon
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Re: MCD19A2 incorrect tile size

by LP DAAC - dgolon » Tue Feb 27, 2024 11:34 am America/New_York

Hello @alexkrart We are looking into your question and will write back when we have additional information. Thanks -- Danielle
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Re: MCD19A2 incorrect tile size

by LP DAAC - lien » Tue Feb 27, 2024 12:25 pm America/New_York

Hi,
Sorry for the misinformation with this. The more precise size of the what is referred to as 500 meter MODIS pixel is actually 463.3127 meters. Each MODIS 500 meter product will have 2400 x 2400 pixels. The native format for the gridded MODIS products are Sinusoidal and this makes the MODIS images appear distorted.
I think this will help you with converting to the pixel coordinates: https://lpdaacsvc.cr.usgs.gov/services/tilemap?help=html
Thanks,
Brett

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