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218      Modern  Spatiotemporal  Geostatistics  —  Chapter  11

        a  theoretical  construction  which  encompasses  the  mathematical and physical
        features  that  geostatisticians  seek.  Due to  space  limitations,  theoretical for-
         mulations for  only a few selected general and specificatory  knowledge bases are
        considered  below  (some of  these formulations  have  been  used  in  applications
        discussed in previous chapters).  There are infinite possibilities,  however, limited
        only  by the  availability  of  physical knowledge bases in  practice.  As  emphasized
        throughout  the  book,  the  theoretical  richness  of  the  BME  construction  is a
        powerful  development in  modern spatiotemporal  geostatistics.
                        Table  11.1.  The  basic  BME equations.

         Equation*                                                Eq.no./














         * Equations appear on p.  1 75-1 76.

        Ordinary     Covariance — Hard         and Soft    Data

        We start  with the  following  fundamental proposition  [the  proof  is very similar
        to  that  of  Proposition  10.1 (p.  198) and is not  included here].

        PROPOSITION     11.1:  Let  x hor. d  be  a  vector  of  hard  data  at  points
        Pi  (i  =  1, 2, ..., irih)  and \ soft  be a  vector  of  soft  data  (of  various
        possible forms; see Table 6.1) at  points p t  (i =  m^ +  1,  . . . , m).  General
        knowledge  includes  the  mean  and  the  (centered)  ordinary  covariance.
        Then,  the  BME  posterior  pdf  is given  by Equation  9.32 (p.  176) with


        and
        where  now



        is  the  mean  vector  for  points  p it  i  =  1, ..., m, fci, . . ,  k p  (notice  the
                                                        .
        difference  compared  to  Eq. 10.3, p. 199), and


        is the  centered  covariance matrix  between all the  points.  The  BMEmode
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