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I have 1 nightlight image of DMSP/OLS. It is uncalibrated. I want to calibrate the image based on Wu's (2013) methodology. Every time I try to run the command "i.nightlights.intercalibration" on GRASS GIS (v. 7.4) I get that error "no data base element found".

Why is that?

I have made every step of Wu's methodology.

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Note that the coefficients provided by Wu et al. 2013 are provided up to the year 2010, so i.nightlights.intercalibration cannot do more here and writes the " "ValueError: The selected model does not know about this combination of Satellite + Year!" message.

For details, see the Wu et al. 2013 paper, esp. Table 2 (PDF) in which they provide coefficients up to 2010 only - this is not a bug in GRASS GIS' i.nightlights.intercalibration module.

Feel free to suggest a better error message which is less confusing, I am happy to update the module respectively then.

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Problem solved. The code running in GRASS, based on Wu's method, cannot recognize the name of the OLS's images that are after the year 2011 (F182011). So the name of the image was renamed from F182011 to F182010. It is important to write exactly the name as it written above. Otherwise GRASSs code cannot execute the proccedure.

  • How old is your local installation of i.nightlights.intercalibration? I fixed a related bug in i.nightlights.intercalibration (lists.osgeo.org/pipermail/grass-commit/2018-March/043287.html). So, be sure to have (re)installed i.nightlights.intercalibration after end of March 2018 – markusN Apr 30 '18 at 14:22
  • I have re-installed the extension but the problem did not get fixed. I get the same error "ValueError: The selected model does not know about this combination of Satellite + Year!" – NikosGr May 5 '18 at 15:46
  • Ah, Wu's method ends in 2010, so it cannot do more here... I answer separately below. – markusN May 6 '18 at 18:02

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