What is the output coordinate frame from IGRF Block?

Dear,

I'm trying to use the IGRF Block from Arerospace Blockset.

The reference is here, Calculate Earth magnetic field and secular variation using 12th generation International Geomagnetic Reference Field - Simulink (mathworks.com)

I'm using trying to use the XYZ output from that block. But my problem is: I'm not sure about the "+ve down" notation as written in the document, is it the same to NED(North East Down) or ENU(East North Up)?

Thank you

Answer 1

[David Coventry]

The coordinate frame is local NED at the requested lat,lon,h location.

The source paper can be used as a reference:

https://earth-planets-space.springeropen.com/articles/10.1186/s40623-015-0228-9

"The geocentric components of the geomagnetic field in the northward, eastward, and radially inwards directions (X, Y and Z) are obtained from the model coefficients using Equation 1 and by taking the gradient of V in spherical polar co-ordinates"

Also, please take a look at the new IGRF block which has the updated IGRF-13 data:

https://www.mathworks.com/help/aeroblks/internationalgeomagneticreferencefield.html

David