# AACGM-v2 Coordinate Transformations  A calculator for transformations between geographic and AACGM-v2 coordinates. For details of the underlying technique, please see preprint [Shepherd, S. G. (2014), Altitude-adjusted corrected geomagnetic coordinates: Definition and functional approximations, J. Geophys. Res., 119, 9, doi:10.1002/2014JA020264.] Supported, in part, by NSF Award ATM-0838356.

## AACGM-v2 Calculator

 Date(s): (YYYY[MM[DD]]) Time(s): (HH[MM]) Latitude(s): (-90 to 90 degrees N) Longitude(s): (-180 to 180 degrees E) Altitude(s):** (0 to 2000 km) * Select: Geographic to AACGM-v2 AACGM-v2 to Geographic Use: Coefficients (10th order) Field-line tracing Coordinates: Geodetic (WGS84) Geocentric (6371.2 km sphere)
 ``` Fill out the form and click submit ```
Important Notes:

1. The coefficients and software used for these calculations are different from the historical AACGM coefficients.
The transformations used here will almost certainly result in different numbers than would be obtained from the historical AACGM software, but
they are more accurate. Please see the following preprint for details.

2.  Multiple values for date, latitude, longitude and altitude are allowed:
- Numbers must be separated by commas
- Lists of numbers must either be the same length or a scalar

3.  *Altitudes above 2000 km require the field-line tracing button to be selected.

4.  **For G2A input altitude(s) are either geodetic (height above sea level) or geocentric (height above sphere RE = 6371.2 km).
Output altitude(s) are geocentric height for both geodetic and geocentric inputs. For A2G input altitude(s) are
geocentric. Output altitudes(s) are either geodetic or geocentric depending on the output selected.

5.  Geographic coordinates can be specified as either geodetic or geocentric. If geodetic is selected then coordinates are transformed to geocentric before
converting to AACGM. For inverse transformations (AACGM to geographic) the resulting geographic coordinates are transformed to geodetic coordinates.