SUBROUTINE FINDPOT (BX,BY,BZ,SWD,SWV,P,AE,RKP,POT1,POT2,POT3)
C  Find potential from the vBsin3(theta/2) formula from Reiff and
C   Luhmann, 1986
C
      DATA RMISS/-32767./, TMISS/-32766.9/
C
      IF (BX.LT.TMISS .OR. BY.LT.TMISS .OR. BZ.LT.TMISS .OR.
     | SWV.LT.TMISS) THEN
       POT1 = RMISS
       POT2 = RMISS
C  In the absence of IMF data, use formula for CP from AE, P, or Kp
C   (in that order of importance)
       POT3 = RMISS
       IF (RKP .GT. TMISS) POT3 = 29. + 11. * RKP
       IF (P .GT. TMISS) POT3 = AMAX1(25., -48.05 + 35.82 * ALOG(P) )
       IF (AE .GT. TMISS) POT3 = 41. + 0.11 * AE
       RETURN
      ENDIF
      B = SQRT(BX**2 + BY**2 + BZ**2)
      THETA = ACOS(BZ/B)
      BU = AMIN1(B,9.)
      POT1 = 12.7 + 0.041 * SWV * BU * ( SIN(THETA/2.) )**3
      CALL CPVBQ1 (BX,BY,BZ,SWD,SWV,POT2)
      POT3 = 12.7 + 0.041 * SWV * BU * ( SIN(THETA/2.) )**3
      RETURN
      END