GSJ Open-File Report, no. 614 Japanese

Calculation of the International Geomagnetic Reference Field (5)

Tadashi Nakatsuka (Institute of Geology and Geoinformation, GSJ/AIST)


  International Geomagnetic Reference Field (IGRF) is a mathematical model of the geomagnetic field originating from the Earth's interior, and it has been adopted at the meeting of the International Association of Geomagnetism and Aeronomy (IAGA).

  This Open-File Report has been revised as follows.

(5)GSJ Open-File Report, no.614
  (this issue)
2015Follow up IGRF-12 generation. Updated C source code
with improved calculation accuracy in polar regions.
  (CD-ROM disk)
(4)GSJ Open-File Report, no.423
2005Follow up IGRF-10 generation, WGS84 ellipsoid.
  (3.5" diskette)
(3)GSJ Open-File Report, no.4022004 Follow up 1992 - 2003 revisions of IGRF models.
Program update for calculating by generation number,
also with C language source. (3.5" diskette)
(2)GSJ Open-File Report, no.1841992 Follow up 1987 - 1991 revisions of IGRF models.
Stored in an electronic media.   (5" diskette)
(1)GSJ Open-File Report, no.271986 1st edition. Explanation of IGRF adoption history till 1985.
FORTRAN code for IGRF calculation.   (only on sheet paper)

  The history of the adoption of IGRF models are summarized as follows.

DatePlace (Assembly)Adoption  Time Span 
Oct., 1968 Washington (IAGA Symp.) 1st Generation: IGRF19651955-1972
Sept., 1973Kyoto (IAGA) Apply IGRF1965 until 19751955-1975
Sept., 1975Grenoble (IUGG) 2nd Generation: IGRF19751955-1980
Aug., 1981Edinburgh (IAGA) 3rd Generation: IGRF1980
Notion of DGRF/PGRF: DGRF1965-1975
Aug., 1985Prague (IAGA) 4th Generation: IGRF1985, DGRF1980
Non-definitive models IGRF1945-1960
Aug., 1987Vancouver (IUGG) 5th Generation: definitive models DGRF1945-1960 1945-1990
Aug., 1991Vienna (IUGG) 6th Generation: IGRF1990, DGRF1985 1945-1995
Sept., 1995Boulder (IUGG) 7th Generation: IGRF1995, DGRF1990
Non-definitive models IGRF1900-IGRF1940
July, 1999Birmingham (IUGG) Set up Task Forcedo.
Dec., 1999(Task Force) 8th Generation: IGRF20001900-2005
Aug., 2001Hanoi (IAGA/IASPEI) DGRF1995 and DGRF2000 are to be discussed at Sapporo in 2003 do.
July, 2003Sapporo (IUGG) 9th Generation: IGRF-9 (DGRF1995, DGRF2000, predictive secular term)
Notation by generation (e.g., IGRF-8 1997.5)
Dec., 2004(Task Force) 10th Generation: IGRF-101900-2010
Dec., 2009(Task Force) 11th Generation: IGRF-111900-2015
Dec., 2014(Task Force) 12th Generation: IGRF-121900-2020

  The text of this report consists of the following sections in Japanese.

    1. Introduction
    2. Outline of IGRF - its history of adoption
    3. Basic formulation for IGRF
    4. Algorithm of calculation
    5. Functions of the subprogram presented
    6. Supplemental information on the subprogram
    7. How to use (example)
    References (in chronological order)
    List of content in appended CD-ROM media

  List of content in appended CD-ROM media.

 openfile0614.html    HTML Document    Manuscript for Introduction Web page   (mainly in Japanese)
 no0614/  Subfolder containing the files below
   igrf.5.pdf  PDF Document  Body text of this open-file report   (in Japanese)
 igrf.c  Simple text  Source code of C language subprogram
 igrf01.coef  Simple text  Gauss coefficients data files of the 1st-12th generation IGRF
  (Header lines are added to the files published by IAGA, to facilitate the input to the program described in this report.)
 index.html  HTML Document  English abstract of this Open-file Report   (This document)
 indexJ.html  HTML Document  Japanese abstract of this Open-file Report

  References (in chronological order)