enter image description hereI have done interpolation (IDW and Nearest Neighbour) in QGIS. But interestingly the output shows the wrong result. The area where I have a huge number of points results in a lower Z value (it is supposed to have a higher Z value). Is it because of the overlapping points?

Another doubt is that kriging algorithm does not show the predicted value (i.e. predicted value is not in the Z value range -160 to 80), though the output curve is meaningful. The prediction shows values in the range -120 to -70 or so. What might be the reason?

closed as unclear what you're asking by Andre Silva, PolyGeo Sep 16 '18 at 8:46

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    Could you please specify what kind of data are you using or upload almost a portion of that raster ? – César Arquero Sep 11 '18 at 9:52
  • Thanks for the reply. I have edited the question and added the screenshot. – sudheesh Sep 11 '18 at 10:36
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    What kind of information does the point layer represent? – csk Sep 11 '18 at 18:50
  • It is about the signal strength – sudheesh Sep 11 '18 at 18:53
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    We need to see some of your dataset and how exactly (tools and parameters) you performed the interpolation. The picture is not helping too much because we can't see the legend and what colors from point represent. If you want to keep the kriging part of the question, add details about it as well. Tks. – Andre Silva Sep 14 '18 at 21:01