| 03 Oct 2010 10:18 PM |
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Hi everybody
I calculated NDVI for pan sharpening with 2.5 meter resolution by ENVI, but I saw some part of NDVI image had high value. These part was soil no vegetation on the Pansherpening image. This is a big question I don't know why this processes doesn’t work for identify vegetation. Also I have been calculated without pan sharpening with 10 meter resolution. The result of NDVI was same as NDVI of pan sharpening with 2.5 m resolution. I hope you give me more accurate answer.
Sincerely Yours, Hadi Fadaei
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MariM
Veteran Member
Posts:2396  
| 04 Oct 2010 11:07 AM |
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You don't mention what type of input data you used to calculate NDVI. Also, which tool did you use? There is NDVI from the Transform menu, there is NDVI from the Vegetation Index Calculator and you can calculate NDVI using Band Math. If you use Band Math, does it differ from what you get in the ENVI tool? What is a 'high value' compared to vegetated areas?
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Deleted User
New Member
Posts: 
| 04 Oct 2010 06:51 PM |
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Hi
My data is ALOS data. i calculate NDVI from the Transform menu, also I calculated NDVI using band math. high value is soil, Flat land in the pansharpening image. in the both result was same. Thank you
Sincerely Yours, Fadaei
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MariM
Veteran Member
Posts:2396
| 05 Oct 2010 08:35 AM |
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I ran a test with AVNIR-2 data (uncalibrated DN) and the values seemed reasonable. The scene had bare soil and vegetated areas. The brightest areas had the highest NDVI (0.4-0.9). Bare soil areas had values near 0. Were you use to use the correct bands for Red and NIR?
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