Nonstationary covariance functions that model space–time interactions
✍ Scribed by Chunsheng Ma
- Book ID
- 104302045
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 149 KB
- Volume
- 61
- Category
- Article
- ISSN
- 0167-7152
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✦ Synopsis
This paper shows how to derive nonstationary spatio-temporal covariance functions via spatio-temporal stationary covariances and intrinsically stationary variograms. Three closely related kernels are employed for this purpose:
(i) 2{'(s 1 ; t 1 ) + '(s 2 ; t 2 )} -'(s 1 + s 2 ; t 1 + t 2 ) -'(s 1 -s 2 ; t 1 -t 2 ), (ii) '(s 1 + s 2 ; t 1 + t 2 ) -'(s 1 -s 2 ; t 1 -t 2 ), (iii) '(s 1 ; t 1 ) + '(s 2 ; t 2 ) -'(s 1 -s 2 ; t 1 -t 2 ), where '(s; t) is an intrinsically stationary variogram. Typical examples of covariances generated by kernel (iii) are those of the Brownian motion and fractional Brownian motion. Many new nonseparable spatio-temporal covariance functions are obtained via kernels (i) and (ii).
📜 SIMILAR VOLUMES
The aim of this work is to construct nonseparable, stationary covariance functions for processes that vary continuously in space and time. Stochastic modelling of phenomena over space and time is important in many areas of application. But choice of an appropriate model can be difficult as we need t