************************************************************************
      SUBROUTINE INIT(fq00,rr00,th00,ph00,es00,dl00)
************************************************************************
      IMPLICIT REAL*8(A-H,O-Z),INTEGER*4(I-N)

      PARAMETER (NSPEC=4)
      COMMON /QCONST/PAI,RAD,DEG,RE,CVLCTY
      COMMON /QPARAM/RREF,RBTM,RREFP,
     &               PF0(NSPEC),GF0(NSPEC),
     &               XN0,THERM,ETA(NSPEC),SHINV(NSPEC),SHINVP,
     &               RRLI,HWLI,
     &               XLPP,HWPP,ERPP,DRR1,DTH1,DPH1,DRR2,DTH2,DPH2,
     &               RRMIN,RRMAX,ERRR,ERRA,HMIN,DISOUT,
     &               NPATH,NLPMAX,INDOUT,INDMSH,IEOF,
     &               IYEAR,IMNTH,IDATE
      COMMON /QINIT /R0,T0,P0,E0,D0,F0

      save inited
      data inited / 0 /
      
      PAI      = dASIN(1.0D0)*2.0D0
      RAD      = PAI/180.0D0
      DEG      = 1.0D0/RAD

      RE       = 6370.0D0
      RREF     = 7370.0D0
      RREFP    = RREF
      RBTM     = 9370.0D0
      CVLCTY   = 3.00D5

      XME      = 9.109534D-31
      XMP      = 1.6726485D-27
      QE       = 1.6021892D-19
      EP       = 8.854185D-12
      XK       = 1.380662D-23
      GM       = 3.98603D14

      PF0(1)   = QE**2/4.0D0/PAI**2/EP/ XME
      PF0(2)   = QE**2/4.0D0/PAI**2/EP/ XMP
      PF0(3)   = QE**2/4.0D0/PAI**2/EP/(XMP*4.0D0)
      PF0(4)   = QE**2/4.0D0/PAI**2/EP/(XMP*16.0D0)
      GF0(1)   =-QE/2.0D0/PAI/ XME        *1.0D-3
      GF0(2)   = QE/2.0D0/PAI/ XMP        *1.0D-3
      GF0(3)   = QE/2.0D0/PAI/(XMP* 4.0D0)*1.0D-3
      GF0(4)   = QE/2.0D0/PAI/(XMP*16.0D0)*1.0D-3

c      XN0      = 32000.0D0
      XN0      = 50000.0D0
c       XN0      = 4000.0D0
      THERM    = 1000.0D0
      SHINV(2) = XMP*       (GM/RREF**2)/XK/THERM*1.0D-3
      SHINV(3) = XMP* 4.0D0*(GM/RREF**2)/XK/THERM*1.0D-3
      SHINV(4) = XMP*16.0D0*(GM/RREF**2)/XK/THERM*1.0D-3
      SHINVP   = SHINV(2)
      ETA(2)   = 0.152D0
      ETA(3)   = 0.82D0
      ETA(4)   = 0.025D0 

c     Following RRLI: location of the lower edge of the ionosphere
      RRLI     = 6370.0d0 + 90.0d0     

c     The following parameters areused in subroutine DENSLI
      HWLI     = 140.0D0
      XLPP     = 4.0D0                      
      ERPP     = 0.2D0
      DRR1     = 5.0D0
      DTH1     = 0.05D0
      DPH1     = 0.2D0
      DRR2     = 2.5D0
      DTH2     = 0.01D0
      DPH2     = 0.1D0

c     Following RRMAX & RRMIN: Upper & lower limit of ray tracing(Km）
c     Following ERRR and ERRA; Initial values for the limiting error
c       and Hmin: Limit of integration increment
      RRMAX    = 4.0*RE
      RRMIN    = 6370.0d0
      ERRR     = 1.0D-5
      ERRA     = 1.0D-5
      HMIN     = 1.0D-10
c     Folowing DISOUT: Every this count, the output data to be printed
      DISOUT   = 200
c     Following NLPMAX: Maximum number of integration loops
      NLPMAX   = 30000
      
      INDOUT   = 21
      INDMSH   = 51
      IEOF     = -1

C...FREQ.(KHZ),GC-DIST.(KM),GM-COLAT.,GM-LONG.,EPS,DEL(DEG)
      F0 = fq00 
      R0 = rr00
      T0 = th00
      P0 = ph00
      E0 = es00
      D0 = dl00

      RETURN
      END