Blue Sky Geoscience (Webb) and Geosoft (Ellis) gave a presentation at an inversion symposium in August 2015, that in part covered the effects of magnetic topography in an area with low magnetic field inclination (Northern Chile).
Forward modelling of the terrain with reference to the location of the helicopter used in the survey showed that most of the near surface magnetic anomalies are due to variations in topography.
Summary slides can be view in the PDF attached to this post. For more information please contact admin@blueskygeo.com
Geosoft also kindly presented some of this work at the 2015 PDAC conference. The discussion starts about 4 minutes into the clip on youtube at the link below