topic KRIGE Result: please help explain something in ArcGIS Spatial Analyst Questions

KRIGE Result: please help explain something

JamesCrandall — Thu, 11 Oct 2012 14:12:34 GMT

In the attached image it shows a raster output result of a Kriging. My focus is on the point near the center of the White color cells that is labeled with 7010 (this is the field/value used to Krig). But if you look at the graduated symbology in the TOC it shows the range as 4509.779643 - 5448.454102

[ATTACH=CONFIG]18363[/ATTACH]

Why is this? I am expecting the Max to be 7010 (I know this is the highest value found in the point FC).

Also, why is the Min value = -535.5955811? I am expecting this to be the lowest value found in the point FC.

Sorry for my inexperience with this subject, I am charged with applying some programmatic automation and doing what I can to educate myself on the subject.

Thanks!

Re: KRIGE Result: please help explain something

JamesCrandall — Thu, 11 Oct 2012 14:35:05 GMT

So I suppose that this is just the product of the Kriging process itself. Perhaps I am expecting something more along the lines of what IDW would produce.

I guess my issues is more about not being certain when and why to apply a certain interpolation over another.

Re: KRIGE Result: please help explain something

MarkBoucher — Thu, 11 Oct 2012 15:13:08 GMT

Look at the http://forums.arcgis.com/threads/68776-Excel-point-data-to-contour-maps post by jbswain from earlier today.

Re: KRIGE Result: please help explain something

EricRice — Thu, 11 Oct 2012 15:21:12 GMT

Very good redirect, Mark.

James, the thing to take away from that pdf in the other thread is that kriging is not an exact interpolator. The values can exceed the input range, and the surface created will not pass through the sample points.

Best,
Eric

Re: KRIGE Result: please help explain something

JamesCrandall — Fri, 12 Oct 2012 10:29:18 GMT

Thanks for the info Mark and Eric!