SUBROUTINE XBTCONV(nobsdp,xprobe)

C     XBTCONV CORRECTS XBT DEPTHS FOR DROP RATE ERROR AS PER
C     SZABADOS PERSONAL COMMUNICATION (1992)

      parameter (maxlevel=6000, maxcalc=200, bmiss=-1.E10)
      double precision dx

c***************************************************************
c
c    Common Block:
c
c     thedata - contains depths and parameter data (temp)
c
c***************************************************************

      common /thedata/ depth(maxlevel),temp(maxlevel,maxcalc)

      iprobe=0
      if ( xprobe .gt. bmiss ) iprobe=xprobe 
      do 20 ij = 1 , nobsdp
 
c     Hanawa et al. 1994 for T4,T6,T7
      if ( iprobe .ne. 219 ) then
c       t=1498.148-sqrt(2244447.430-462.963*depth(ij))
cx      depth(ij)=6.733*t-.00254*t**2
c       depth(ij)=6.691*t-.00255*t**2
        dx=depth(ij)*1.D+00
        dx=(1.0417*dx)-(75.906*(1-((1-(.0002063*dx)))**.5))
        depth(ij)=dx
        if ( depth(ij) .lt. 0.0 ) depth(ij)=0.
        if ( isitnan(depth(ij)) .ne. 0 ) depth(ij)=0.
c       write(6,*) 'ij',ij,depth(ij)
       else
c      Kizu et al. 2005 for TSK T5
        if ( depth(ij) .le. 250 ) then
         depth(ij)=depth(ij)*0.9572
        elseif ( depth(ij) .le. 500 ) then
         depth(ij)=depth(ij)*0.9565
        elseif ( depth(ij) .le. 750 ) then
         depth(ij)=depth(ij)*0.9558
        elseif ( depth(ij) .le. 1000. ) then
         depth(ij)=depth(ij)*0.9550
        elseif ( depth(ij) .le. 1250. ) then
         depth(ij)=depth(ij)*0.9542
        elseif ( depth(ij) .le. 1500. ) then
         depth(ij)=depth(ij)*0.9533
        else
         depth(ij)=depth(ij)*0.9524
        endif 
       endif
20    continue
 
      return
      end