- Jun 1 4:10 PMDear all,

I am looking for the "ultimate" truth about the Linear Model of

Coregionalization!

I want to model the variograms of variable A and B, and the

cross-variogram of variables A-B. The variogram and cross-

variogram models cannot be built independently from one

another (Issaks & Srivastava, 1989; Goovaerts, 1997).

This is where the Linear Model of Coregionalization comes

into play: any basic model that is included in the cross-

variogram model must be included in all the variogram

models (ibid.).

I have a program for calculating variogram and cross-

variogram models that can handle only one basic model for

each (cross-) variogram, i.e. no nested structures are allowed.

From the above description of the Linear Model of

Coregionalization does it now follow that

Question 1:

if I use e.g. a spherical model for the cross-variogram of

variables A-B, I have to use a spherical model for both, the

variogram of variable A and the variogram of variable B?

And further:

Question 2:

The ranges of both variogram models and the range of the cross-

variogram model have to be identical?

Question 3:

What are the consequences of violating the Linear Model of

Coregionalization? Some people seem to think that it is o.k.

to ignore the Linear Model of Coregionalization as long as

they appear to get reasonable results from their analysis.

The reason for my confusion comes from the fact that I have

seen both cases in the literature:

people using the same variogram models and the same ranges

for their variograms and cross-variograms, and

people (non-geostatisticans?) using different models (e.g.

an exponential model for variogram A, a spherical model

for variogram B, and a Gaussian model for the cross-

variogram A-B) with different ranges.

I would really appreciate any comments that could

shed some light on this (for me) confusing topic!

Thanks for your help and have a nice day!

Gerhard

--

******************************************************************

| Gerhard Hunner |

|----------------------------------------------------------------|

| Ph.D. candidate |

| Geostatistics, GIS, Remote Sensing |

|----------------------------------------------------------------|

| GIS and Remote Sensing Program |

| Department of Forest Sciences |

| Colorado State University |

| Fort Collins, CO 80523 |

| USA |

| Tel.: (970) 221-1826 |

| Fax: (970) 491-6754 |

| Email: gerhard@... |

******************************************************************

--

*To post a message to the list, send it to ai-geostats@....

*As a general service to list users, please remember to post a summary

of any useful responses to your questions.

*To unsubscribe, send email to majordomo@... with no subject and

"unsubscribe ai-geostats" in the message body.

DO NOT SEND Subscribe/Unsubscribe requests to the list! - Next post in topic >>