HICO l2 projection problem

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junzhao
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HICO l2 projection problem

by junzhao » Thu Nov 13, 2014 1:45 am America/New_York

Hi there,
I posted the same question in 'SeaDAS 7 - General questions'. But I haven't got any responses. Maybe I posted in the wrong place. So I post it again.
A hico level 2 product was projected in Seadas V7.1. However, there are some problems at the right and left corners. An representative image is attached here. Please advise.
Thanks.
Jun

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OB WebDev - norman
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HICO l2 projection problem

by OB WebDev - norman » Thu Nov 13, 2014 5:07 pm America/New_York

Hi Jun,

I had a look at the HICO scene you refer to and find the
geolocation information has no unexpected corner anomalies.
I am attaching a 3-band image I made from the data without
using SeaDAS.  We'll need to investigate further.

In the mean time, can you post the exact steps you used
to make your image?

Regards,
Norman

OB.DAAC - SeanBailey
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HICO l2 projection problem

by OB.DAAC - SeanBailey » Fri Nov 14, 2014 12:29 pm America/New_York

By default, the Reprojection tool uses a nearest neighbor resampling approach.  It offers two others: bilinear and bicubic.
If you select the bicubic approach, the reprojected image does not have these 'wing-like' artifacts.  I will contact our BEAM
partners (who developed the reprojection tool) to see if they can identify why these artifacts occur with the nearest neighbor
(and apparently the bilinear) option

Regards,
Sean

junzhao
Posts: 28
Joined: Fri Oct 07, 2011 11:21 am America/New_York

HICO l2 projection problem

by junzhao » Sun Nov 16, 2014 12:20 am America/New_York

Hi Sean,
Thanks. You're right. If the 'bicubic' resampling method is selected, the artifact is gone.
@Norman. The step I used was
Processing -> Reproject.
The output format was set as 'GeoTIFF'. The other parameters are as default.
According to Sean's reply, everything is fine now.
Thanks again.
Jun

junzhao
Posts: 28
Joined: Fri Oct 07, 2011 11:21 am America/New_York

HICO l2 projection problem

by junzhao » Sun Nov 16, 2014 12:26 am America/New_York

BTW, is it possible to do the reprojection from the command line?
Jun

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HICO l2 projection problem

by OB.DAAC - SeanBailey » Mon Nov 17, 2014 3:29 pm America/New_York

Yes, using GPT (the Graph Processing Tool).   We're still working on a decent tutorial for this, however, there are several posts on this forum with examples.
There is also an overview presentation on the subject.

Regards,
Sean

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HICO l2 projection problem

by obdaac_forum_user » Mon Jan 12, 2015 7:28 am America/New_York

Nice post... It is a great post to enhance my information about HICO. Now i came to know what is full form and what is its work....

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