ANAM: Programs for Reduction and Quantitative Interpretation of Magnetic Anomaly data

Contents
emag/emagf tmcorr emeq emeqs edeq edeqs calmas
amag/amagc tmcfix ameq ameqs adeq adeqs
cmag/cmagf     lcecorr ameqc     ameqsc     adeqc     adeqsc     Standard GridData Format
plamag aaptdp cmeq cmeqs cdeq cdeqs StdLIN data Format
plamagc galtf/galts     rpmeqs rpdeqs GDMP (Grid Data Manipulation)
 
Program Name Function
emag/emagf Calculate COEF matrix to prepare for Magnetization Intensity Mapping. emagf takes the surface undulation into consideration with the resolution of terrain data, while emag approximates the source into blocks with source grid size. Here emagf requires the source grid size be a multiple of the grid size of terrain data.
          Parameters: log filename
input magnetic anomaly data filename (*1)
source altitude data filename
source location parameters (*2)
truncation of source effect (km)
source bottom configuration (*3)
ambient field direction
magnetization direction
COEF matrix output filename
AMAG initial model output filename
amag/amagc Execute Magnetization Intensity Mapping, making use of COEF matrix from emag/emagf process as far as specified loop count or until converge..
          Parameters: log filename
input magnetic anomaly data filename
with removing linear trend or not
COEF matrix input filename
AMAG model in/out filename
auxiliary output filename
[amag] number of loops / [amagc] convergency torelance (*5)
cmag/cmagf Calculate synthetic magnetic anomaly distribution on the specified surface caused by the result of Magnetization Intensity Mapping. cmagf takes the surface undulation into consideration with the resolution of terrain data, while cmag approximates the source into blocks with source grid size. Here cmagf requires the source grid size be a multiple of the grid size of terrain data.
          Parameters: log filename
calculation altitude input filename
AMAG model input filename
source altitude data filename
truncation of source effect (km)
source bottom configuration (*3)
ambient field direction
magnetization direction
output data filename
plamag Draw contour map of the result of Magnetization Intensity Mapping on an A4 sheet. Surrounding source zone is masked, and the range of drawing can be limited.
          Parameters: log filename
input AMAG data filename
ref. obs.anomaly data filename
no. of grids [S,N] to limit drawing range
no. of grids [W,E] to limit drawing range
output PS filename
paper orientation
contour interval (A/m)
size of drawing
supplementary items (scale bar, meridians and parallels, coastlines etc.)
plamagc Draw color-graded contour map of the result of Magnetization Intensity Mapping on an A4 sheet. Surrounding source zone is masked, and the range of drawing can be limited.
          Parameters: log filename
input AMAG data filename
ref. obs.anomaly data filename
no. of grids [S,N] to limit drawing range
no. of grids [W,E] to limit drawing range
output PS filename
paper orientation
color-grading interval (A/m)
median value of grading (A/m)
contour-line interval (A/m)
size of drawing
supplementary items (scale bar, meridians and parallels, coastlines etc.)
tmcorr Correction of the effect of terrain uniform magnetization for observed magnetic anomaly GRID data.
          Parameters: log filename
observed magnetic anomaly data filename (*1)
with removing linear trend (y) or only DC level (n)
topography data filename
truncation distance of source effect (km)
source bottom configuration
ambient field direction
magnetization direction
terrain corrected output filename
auxiliary output filename
tmcfix Correction of fixed terrain magnetization effect for observed magnetic anomaly GRID data.
          Parameters: log filename
observed magnetic anomaly data filename (*1)
topography data filename
truncation distance of source effect (km)
source bottom configuration
ambient field direction
magnetization direction
magnetization intensity
terrain corrected output filename
lcecorr Correction of the railway loop-current effect for observed magnetic anomaly GRID data.
          Parameters: log filename
observed magnetic anomaly data filename (*1)
loop location data filename
ambient field direction
range of loop-current estimation
LCE corrected output filename
auxiliary output filename
aaptdp Point-dipole source modeling for observed magnetic anomaly GRID data. Each time a fitting window is selected, one source model is fitted automatically, and its effect is removed from the observed magnetic anomaly.
          Parameters: log filename
observed magnetic anomaly data filename (*1)
ambient field direction
areaname label for model anomaly
model anomaly output filename
areaname label for residual data
residual data output filename
how to define window (UTM coordinates / mesh-count)
[repeated until blank line] data specifying window
galtf Interpolate observation altitude of StdLIN data into GRID data.
          Parameters: log filename
input StdLIN data filename
effecting radius (km)
(new) areaname label
map projection coordinate number (*4)
location parameters (*2)
output data filename
galts Generate GRID data of smoothed observation altitude from StdLIN data.
          Parameters: log filename
input StdLIN data filename
smoothing radius (km)
(new) areaname label
map projection coordinate number (*4)
location parameters (*2)
output data filename
emeq Calculate CMUP matrix to prepare for Altitude Reduction by Equivalent Anomaly method [Equivalent source surface is defined as a certain distance below the specified reduction-to surface, and the magnetic anomaly distribution on the source surface is derived from observed data by an inversion analysis, then the magnetic anomaly distribution on the specified surface is calculated as a continuation operation].
          Parameters: log filename
input magnetic anomaly data filename (*1)
reduction-to altitude data filename
distance of source surface below the reduction-to surface (m)
truncation of source effect (km)
CMUP matrix output filename
AMEQ model initializing output filename
ameq/ameqc Execute Altitude Reduction by Equivalent Anomaly method, making use of CMUP matrix from emeq process as far as specified loop count or until converge.
          Parameters: log filename
input magnetic anomaly data filename
CMUP matrix input filename
AMEQ model in/out filename
[ameq] number of loops / [ameqc] convergency tolerance (*5)
cmeq Calculate magnetic anomaly distribution on the specified reduction-to surface, from the Equivalent Anomaly distribution AMEQ derived by ameq/ameqc process.
          Parameters: log filename
reduction-to altitude data filename
AMEQ model input filename
truncation of source effect (km)
reduction result data output filename
emeqs Calculate CMUPS matrix to prepare for Altitude Reduction by Equivalent Source Magnetization method [Equivalent source surface is defined as a certain distance below the specified reduction-to surface, and the magnetization distribution on the source surface is derived from observed data by an inversion analysis, then the magnetic anomaly distribution on the specified surface is forward calculated].
          Parameters: log filename
input magnetic anomaly data filename(*1)
reduction-to altitude data filename
distance of source surface below the reduction-to surface (m)
truncation of source effect (km)
ambient field direction
magnetization direction
CMUPS matrix output filename
AMEQS model initializing output filename
ameqs/ameqsc Execute Altitude Reduction by Equivalent Source Magnetization method, making use of CMUPS matrix from emeqs process as far as specified loop count or until converge.
          Parameters: log filename
input magnetic anomaly data filename
CMUPS matrix input filename
AMEQS model in/out filename
[ameqs] number of loops / [ameqsc] convergency tolerance (*5)
cmeqs Calculate magnetic anomaly distribution on the specified reduction-to surface, from the Equivalent Source Magnetization distribution AMEQS derived by ameqs/ameqsc process.
          Parameters: log filename
reduction-to altitude data filename
AMEQS model input filename
truncation of source effect (km)
reduction result data output filename
rpmeqs Calculate reduction-to-pole magnetic anomaly distribution on the specified reduction-to surface, translating the Equivalent Source Magnetization AMEQS derived by ameqs/ameqsc process into vertical, and also assuming vertical ambient magnetic field direction.
          Parameters: log filename
reduction-to altitude data filename
AMEQS model input filename
truncation of source effect (km)
calculated reduction-to-pole data output filename
edeq Calculate CFUP matrix to prepare for Altitude Reduction from StdLIN line data by Equivalent Anomaly method [Equivalent source surface is defined as a certain distance below the specified reduction-to surface, and the magnetic anomaly distribution on the source surface is derived from observed StdLIN data by an inversion analysis, then the magnetic anomaly distribution on the specified surface is calculated as a continuation operation].
          Parameters: log filename
StdLIN line data filename
reduction-to altitude data filename
distance of source surface below the reduction-to surface (m)
truncation of source effect (km)
CFUP matrix output filename
ADEQ model initializing output filename
adeq/adeqc Execute Altitude Reduction from StdLIN line data by Equivalent Anomaly method, making use of CFUP matrix from edeq process as far as specified loop count or until converge.
          Parameters: log filename
StdLIN line data filename
CFUP matrix input filename
ADEQ model in/out filename
[adeq] number of loops / [adeqc] convergency tolerance (*5)
cdeq Calculate magnetic anomaly distribution on the specified reduction-to surface, from the Equivalent Anomaly distribution ADEQ derived by adeq/adeqc process.
          Parameters: log filename
reduction-to altitude data filename
ADEQ model input filename
truncation of source effect (km)
reduction result data output filename
edeqs Calculate CFUPS matrix to prepare for Altitude Reduction from StdLIN line data by Equivalent Source Magnetization method [Equivalent source surface is defined as a certain distance below the specified reduction-to surface, and the magnetization distribution on the source surface is derived from observed StdLIN data by an inversion analysis, then the magnetic anomaly distribution on the specified surface is forward calculated].
          Parameters: log filename
StdLIN line data filename
reduction-to altitude data filename
distance of source surface below the reduction-to surface (m)
truncation of source effect (km)
ambient field direction
magnetization direction
CFUPS matrix output filename
ADEQS model initializing output filename
adeqs/adeqsc Execute Altitude Reduction from StdLIN line data by Equivalent Source Magnetization method, making use of CFUPS matrix from edeqs process as far as specified loop count or until converge.
          Parameters: log filename
StdLIN line data filename
CFUPS matrix input filename
ADEQS model in/out filename
[adeqs] number of loops / [adeqsc] convergency tolerance (*5)
cdeqs Calculate magnetic anomaly distribution on the specified reduction-to surface, from the Equivalent Source Magnetization distribution ADEQS derived by adeqs/adeqsc process.
          Parameters: log filename
reduction-to altitude data filename
ADEQS model input filename
truncation of source effect (km)
reduction result data output filename
rpdeqs Calculate reduction-to-pole magnetic anomaly distribution on the specified reduction-to surface, translating the Equivalent Source Magnetization ADEQS derived by adeqs/adeqsc process into vertical, and also assuming vertical ambient magnetic field direction.
          Parameters: log filename
reduction-to altitude data filename
ADEQS model input filename
truncation of source effect (km)
calculated reduction-to-pole data output filename
calmas Calculate theoretical magnetic anomaly distribution on the specified observation surface, caused by a symple source model (rectangular block, horizontal rectangle with infinitesimal thickness, vertical line segment with infinitesimal thickness, point with infinitesimal volume or any combination of them).
          Parameters: log filename
observation altitude data filename
calculated result output filename
how to specify position (0: Coord. values / 1: Distance from SW corner)
ambient field direction
[may be repeated]
    Model type (1:Block, 2:hRect, 3:vLine, 4:Point)
    Northing (km) (Median and NS size for Block/hRect)
    Easting (km) (Median and EW size for Block/hRect)
    Depth (km) (Top and bottom for Block/vLine)
    [for other than Block] effective thickness/sectional area/volume
    Magnetization (A/m)
    magnetization direction
[at the end] 0 [: Model type]
(*1) If observation altitude of input GRID data is undefined, additional altitude data input will be required.
(*2) "location parameters" include Northing and Easting of Southwest corner, mesh interval and number of mesh to the North, and to the East.
(*3) "source bottom configuration" is selected from Flat Bottom or Constant Thickness model, with specification of its depth or thickness.
(*4) If the map projection is not UTM, information of the origin will be required.
(*5) The process is finalized if the percentage of improvement in RMS mismatch is less than the specified value (default: 2%) for 5 continuous iterations, or if the RMS misfit becomes less than 0.1 nT.


Standard Format of GRID data file v2005

 1.   One file consists of 1 set of GRID data, or multiple sets of GRID data.
    The 2nd set or further behind of multiple sets of GRID data is restricted
    in usage, and is valid only for cases below.
      (1) 1st set GRID data indicates a distribution of any physical quantity
        on a curved surface, and the altitude distribution of the surface is
        given by 2nd set GRID data.
      (2) The file consists of a series of independent GRID data, and they are
        not used for other than illustrating each distribution.
 2.   The unit for the physical quantity (grid data) is, in principle,
    nT for magnetic field, m for altitude, 0.01 A/m for magnetization, mGal
    for gravity, or others as derived from them.  And it is recommended to use
    the value of positive 99999 in effective digits for representing null
    value (the lack of valid data).
 3.   Every data line in GRID data file may not exceed 80 bytes excluding LF
    code.  And it is recommended to be 79 bytes or less excluding LF.
 4.   Data in GRID data file may not include multi-byte characters, and
    control codes other than LF shall not be used.

Each set of GRID data is constructed as follows.
a) Comment: Before 1st Header, arbitrary lines of comment can be placed.
        Comment line has "#" on the 1st column and is 80 byte long at most.
b) 1st Header (Areaname and information of map projection)  [fixed format]
      FORMAT(a8, i4,4x, 2i8, 2i8)
  area: 8 byte string representing Areaname or else, not starting with "#".
  nc:   coordinate number of map projection (usually UTM zone number)
            0 : Japanese transverse Mercator coordinates
         1-60 : UTM coordinates zone number
           61 : North pole UPS coordinates
           62 : South pole UPS coordinates
           65 : UTM coordinates with non-standard central meridian
           70 : Mercator projection
           71 : Lambert conformal conic projection (1 standard parallel)
           72 : Lambert conformal conic projection (2 standard parallels)
          100 : Lambert Azimuthal Equal-Area Projection
                (from the sphere with surface area equal to the earth)
          109 : Lambert Azimuthal Equal-Area Projection
                (from the sphere with equatorial radius equal to the earth)
          199 : Latitude/Longitude in minutes are regarded as distance in km
        These numbers above are for the Bessel ellipsoid (Tokyo datum).
        For GRS ellipsoid (WGS-ITRF), add 200 to the corresponding projection.
  ig, kg : Latitude and Longitude (in minutes) of origin
            [neglected for nc = 1 to 62]
  i1, i2 : Latitudes (in minutes) of standard parallels
            [valid only when nc = 72]
    In general, coordinate values are X (Northing) = Y (Easting) = 0 at the
    origin.  However, in UTM (nc = 1 to 60, or 65) X = 0, Y = 500,000 (m), and
    in UPS (nc = 61 or 62) X = Y = 2,000,000 (m), at the origin.
c) 2nd Header (Grid information, null value and altitude)  [free format]
      FORMAT(2i12, 2i6, 2i6, 1x,f7.1, 1x,f7.0)   (as standard)
  ixs, iys : Northing and Easting (in m) of Southwest corner of GRID  [integer]
  mszx,mszy: mesh size (in m) towards North and East                  [integer]
  mxn, myn : mesh count (including both ends) towards North and East  [integer]
  vnul :     special value representing the lack of valid data        [real]
  alt :      observation altitude (in m)                              [real]
              (If the value = 0., the distribution of observation surface is
               given as 2nd set GRID data, and if negative (-1.), the altitude
               of observation is undefined.  For the 2nd set GRID data (i.e.,
               altitude data) this is filled with -1., though meaningless.)
d) GRID data body  [free format]
      FORMAT((f7.1, 9(1xd,f7.1)))   (as standard)
  All grid data are listed out in the order that starts from Southwest corner
  toward North, and on arriving North end proceeds to next East row.
  Next expression is the equivalent FORTRAN statement reading this data.
        read(10,*) ((f(i,k),i=1,mxn),k=1,myn)
  However, for the output programming, line break operation between rows
        do 1 k=1,myn
          write(10,'((f7.1,9(1x,f7.1)))') (f(i,k),i=1,mxn)
      1 continue
  is recommended.

StdLIN line data Format (example)

# Areaname: Kobe-Kyoto
# Survey Date: 1995.12.07-12.27
&A-01
 2079.0222N  8116.2764E   277.8m   -45.1nT
 2079.0405N  8116.3164E   278.5m   -44.6nT
 2079.0588N  8116.3564E   279.1m   -44.4nT
        .......
 2087.3958N  8134.2559E   275.4m   -48.3nT
 2087.4158N  8134.2964E   275.4m   -53.6nT
&    C-2r
 2088.2712N  8134.3799E   279.1m   -44.9nT
 2088.2563N  8134.3384E   279.3m   -40.8nT
 2088.2407N  8134.2964E   279.6m   -40.1nT
        .......
     Lines starting with '#' are comment information, usually placed only at
       the head of the file.  (Never be placed among series of line data.)
     Lines starting with '&' or '%' indicate the start of line data.
       Line name (number) is described in 2nd-9th columns, and the form of
       the rest is not restricted.  (Starting time and number of data points
       included are commonly described.)
       In some cases, a line with no data points is defined for explicit
       declaration of the end of file.
     All other lines are data of individual points, consisting of Latitude
       (in minutes), Longitude (in minutes), Altitude (in m), and Residual
       magnetic anomaly (in nT) data, with the format (42 columns) of
          format(f10.4, 1hN, f11.4, 1hE, f8.1, 1hm, f8.1, 2hnT).