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When you are working with Landsat Level 1 data and calculate indexes, e.g. NDVI, NDBI, SAVI ..., do you calculate them using raw data (pixel DN value), or atmospherically corrected data (surface reflectance)?

  • What is your use case? – BillyWill Jul 7 '15 at 8:21
  • Billy, temporal analyses of area near factory. Aaron post a good article so I found answer. – ABCD Jul 7 '15 at 9:26
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It depends upon the intended use of the Landsat data. Generally speaking, if you are doing multi-temporal analyses, you need atmospherically corrected data, otherwise DN format is sufficient. I would recommend reading the following landmark paper on the subject:

Song, C., Woodcock, C. E., Seto, K. C., Lenney, M. P., & Macomber, S. A. (2001). Classification and change detection using Landsat TM data: when and how to correct atmospheric effects?. Remote sensing of Environment, 75(2), 230-244.

From the conclusion in Song et al. 2001:

Atmospheric correction is not always necessary for classification and change detection. Both simple theoretical analysis and empirical results indicate that only when training data from one time or place are applied in another time or place is atmospheric correction necessary for image classification and many change detection methods.

  • 4
    Whereas, I mostly agree with @Aaron (and Song et al., 2001), keep in mind that there is a camp that ardently believes that spectral indices are invalid without correction. The rational is that atmospheric effect is not uniform therefore, without correction, there would be spatially distributed bias, creating inconsistency in the metric and influencing inference. I would say that this is a quite valid point and if you get somebody in this camp in review you may have your paper rejected. It seems like a small processing step to avoid this debate. – Jeffrey Evans Jul 6 '15 at 18:01
  • Agree with Aaron. Depends on the intended use of the data. The challenge however is having enough experience to know when the data will become overly biased. Could the OP describe the intended use? – BillyWill Jul 7 '15 at 8:21
  • @BillyWill, temporal analyses of area near factory. – ABCD Jul 7 '15 at 9:29

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