topic Re: Interpreting Crosscovariance Cloud in ArcGIS GeoStatistical Analyst Questions

Interpreting Crosscovariance Cloud

MohsenYsf — Mon, 02 Apr 2018 17:05:03 GMT

Hello User Community,

I have some difficulty in order to interpret the meaning of these results. (results have been attached)

I want to use this correlation between each two variables in order to determine the range, the maximum distance that two variables correlate with each other. But I don’t know how can i get it by crosscovariance cloud!

I would be grateful if you could help me to overcome this problem.

Thanks in advance.

Re: Interpreting Crosscovariance Cloud

EricKrause — Mon, 02 Apr 2018 19:14:30 GMT

I took a quick look at your images. For most of them, the crosscovariances are near 0 (or even negative) for short distances. This implies that there is little correlation between the variables. The idea is that for short distances, the variables should have high crosscovariance (indicating that they are correlated). This covariance should decrease as the distance increases until they level out near zero (which indicates that they are no longer correlated). You need to try to identify the distance where these covariances generally become zero. However, it isn't clear to me from those pictures if there is any crosscovariance between the variables at all.

You may be able to better identify the distance you need in the Geostatistical Wizard. Perform cokriging, and look at the crosscovariance view on the semivariogram page. This graph won't have as many points as the cloud, and it will try to fit a covariance model automatically. Whatever Major Range is estimated should be a good estimate of the range of crosscovariance between the variables.

Re: Interpreting Crosscovariance Cloud

MohsenYsf — Tue, 03 Apr 2018 13:17:11 GMT

Hi Eric,

Thanks for being willing to take a look at my images. I was struggling to comprehend the Crosscovariance Cloud results. Your answer was very helpful.
Regards, Mohsen.