hdg_decl: Calculate declination, true heading, and magnetic heading

In paleolimbot/headings: Tools for Working with Compass Headings

Description

For more detailed output, see wmm2020_extract().

Usage

hdg_decl(
  lon,
  lat,
  year,
  height = 0,
  height_ref = c("geoid", "ellipsoid"),
  model = c("IGRF13", "WMM2020", "EMM2017")
)

hdg_true_from_magnetic(
  hdg,
  lon,
  lat,
  year,
  height = 0,
  height_ref = c("geoid", "ellipsoid"),
  model = c("IGRF13", "WMM2020", "EMM2017")
)

hdg_magnetic_from_true(
  hdg,
  lon,
  lat,
  year,
  height = 0,
  height_ref = c("geoid", "ellipsoid"),
  model = c("IGRF13", "WMM2020", "EMM2017")
)

Arguments

lon	Vectors of coordinates.
lat	Vectors of coordinates.
year	A decimal year (e.g., 2020.2120). The World Magnetic Model is valid between 2020.0 and 2025.0; the Enhanced Magnetic Model is valid between 2000.0 and 2022.0.
height	A height above the earth's surface (as approximated by the EGM9615 geoid) in kilometers. If height_ref is "ellipsoid", this is interpreted as the height above the WGS84 ellipsoid.
height_ref	One of geoid or ellipsoid.
model	One of IGRF13, WMM2020, or EMM2017.
hdg	A heading in degrees, where 0 is north, 90 is east, 180 is south, and 270 is west. Values outside the range [0-360) are coerced to this range using hdg_norm().

Value

A declination, true heading, or magnetic heading.

Examples

hdg_decl(-64, 45, year = 2021)
hdg_true_from_magnetic(13.40, -64, 45, year = 2021)
hdg_magnetic_from_true(356.51, -64, 45, year = 2021)

paleolimbot/headings documentation built on April 14, 2021, 8:33 a.m.