SuperDARN AACGM library is using old coefficients

spedas / bleeding_edge

IDL-based Space Physics Environment Data Analysis Software (bleeding edge)

http://www.spedas.org

Other

7 stars 0 forks source link

SuperDARN AACGM library is using old coefficients #81

Open ericthewizard opened 1 year ago

ericthewizard commented 1 year ago

A user reported the following:

year=2016
t0=3600.*24*31.+3600.*6.
glat=56.4
glon=265.4
hgt=110.

aacgmconvcoord, glat,glon,hgt, mlat,mlon,err,/TO_AACGM

Uses old coefficients:

AACGM coef path: /Users/eric/trunk/general/cotrans/aacgm/coef/aacgm_coeffs Year list of coef. files available: 1975 1980 1985 1990 1995 2000 2005 2010

jameswilburlewis commented 1 year ago

The SuperDARN code should probably be updated to use the AACGM_V2 library which is bundled with SPEDAS. That version has coefficients that are good through 2025.

jameswilburlewis commented 1 year ago

~~It looks like the latest coefficients could be backported to the existing AACGM V1 libraries.~~. Actually, the IGRF13 coefficients file doesn't seem compatible with the AAGCM (version 1) model. The number of entries doesn't add up, and there don't appear to be any values in common between the yearly columns in the IGRF13 file and the corresponding aacgm_coeffsYYYY.asc files under general/cotrans/aacgm/coef .

New coefficients are here (last column of table):

https://www.ngdc.noaa.gov/IAGA/vmod/coeffs/igrf13coeffs.txt