Cain Mars crustal model magnetic field

• Brief description of Cain model: A potential function using spherical harmonics up to degree and order 90 was derived from a selection of Mars Global Surveyor (MGS) vector data. These included all three components of those taken below 200 km altitude during the two aerobraking phases (AB1 and AB2), the Science Phase Orbits (SPO), and the higher altitude (367435 km) data taken on the nightside during the Mapping Phase Orbits (MPO). The merger of these sets of data provided total global coverage. The technique used was a least squares minimization developed for Earth field analysis whereby the relative weighting of each data source was determined by the width of a Gaussian fit to the residual distribution about the potential function. Also, data selection by area and area weight functions were used to improve normalization. Comparisons with other published maps and models for Mars show general agreement with the field representations at MPO altitudes, but disagreements up to several hundred nT in components calculated for areodetic altitudes below 200 km
• A detailed description along with complete references is available here.