Geoid datasets used by the GeographicLib::Geoid class and the GeoidEval
tool to compute geoid heights.

  Available geoid data files
                                  size (MB)
  name         geoid    grid    tar.bz2  disk
  egm84-30     EGM84    30'      0.5      0.6
  egm84-15     EGM84    15'      1.5      2.1
  egm96-15     EGM96    15'      1.5      2.1
  egm96-5      EGM96     5'       11       19
  egm2008-5    EGM2008   5'       11       19
  egm2008-2_5  EGM2008   2.5'     35       75
  egm2008-1    EGM2008   1'      170      470

Gravity models used by the GeographicLib::GravityModel class and the
Gravity tool to compute gravity fields.

  Available gravity models
                       size (kB)
  name     degree    tar.bz2  disk
  egm84      18       27      26
  egm96      360     2100    2100
  egm2008   2190    76000   75000
  wgs84      20        1       1
  grs80      20        1       1

Magnetic models used by the GeographicLib::MagneticModel class and the
MagneticField tool to compute magnetic fields.

  Available magnetic models
                                  size (kB)
  name     degree    years      tar.bz2  disk
  wmm2010    12    2010-2015      2       3
  wmm2015    12    2015-2020      2       3  *deprecated*
  wmm2015v2  12    2015-2020      2       3
  wmm2020    12    2020-2025      2       3
  igrf11     13    1900-2015      7      25
  igrf12     13    1900-2020      7      26
  igrf13     13    1900-2025      7      28
  emm2010   739    2010-2015    3700    4400
  emm2015   729    2000-2020     660    4300
  emm2017   790    2000-2022    1740    5050

The size columns give the download and installed sizes of the datasets.