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New Contributor
Posts: 3
Registered: ‎04-16-2020
Accepted Solution

Negative DN values after the TOA correction of Landsat images.

Hello everyone,

 

I am correcting different images DNs  to TOA Reflectance using spatial Modeler of ERDAS Imagine 2015. the problem is this:

It keeps showing negative values after the correction but only for band 5 and 7 for landsat 5 and bands 6 and 7 for landsat 8 even if I add a Set to NoData operator into the spatial model.  What should I do? 

 

 

 

correction_problem.png

Technical Evangelist
Posts: 1,079
Registered: ‎10-01-2015

Re: Negative DN values after the TOA correction of Landsat images.

Correction to TOA Reflectance is not necessarily an exact science. The correction can end up with negative values.

 

But first, check that you have defined your inputs correctly based on the input image. 

 

If those are all correct you may wish to consider extending the Spatial Model to truncate at 0.

 

Cheers

Ian Anderson
Chief Product Owner, Desktop Remote Sensing
Hexagon Geospatial