Synthetic Magnetic Anomaly Calculation (CALMA)

NAME
    magafd - Define directions of magnetization and ambient magnetic field
    mpoint - Specify point source and its parameter
    mvline - Specify vertical line source and its parameter
    mhrect - Specify horizontal rectangle surface source and its parameter
    mprism - Specify rectangular block source and its parameter
    calma  - Calculate magnetic anomaly (total intensity anomaly) at specified
             observation point.  Any directional component may be calculated
             by setting its direction as ambient field direction.

 (Note)  Assume righthanded Cartesian coordinates X pointing North, Y pointing
       East, and Z pointing Down.  All units of lengths can be arbitrary as far
       as they are common to all lengths.

SYNOPSIS

      call magafd(the, phi, dip, dec)
  the, phi  [float]  Inclination and declination (in degrees) of magnetization
  dip, dec  [float]  Inclination and declination (in degrees) of ambient field
                      (Earth's magnetic field)

      call mpoint(am, xc, yc, zc, vol)
      call mvline(am, xc, yc, za, w, area)
      call mhrect(am, cx, rx, cy, ry, zc, h)
      call mprism(am, cx, rx, cy, ry, za, w)
  am        [float]  Magnetization intensity (in A/m)
  xc, yc    [float]  Horizontal coordinates of source
  zc        [float]  Downward coordinate of source
  cx, rx    [float]  X-axis range (median and range value) of source
  cy, ry    [float]  Y-axis range (median and range value) of source
  za, w     [float]  Top depth and depth range of source
                     If w=0., bottom unlimitted model is assumed.
  vol       [float]  Volume represented by a point
                      (in the unit of cube of common length unit)
  area      [float]  Area of cross-section represented by a line
                      (in the unit of square of common length unit)
  h         [float]  Thickness of the body represented by a surface
                      (in the unit common with lengths)

      f = calma(xp, yp, zp)
  xp, yp    [float]  Horizontal coordinates of the point of calculation
  zp        [float]  Depth coordinate of the point of calculation
  f         [float]  Calculated result.
                     Total force (in nT) value of magnetic anomaly is given.