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MF4 is a field model representing the visible part of the crustal
magnetic field. It is derived from almost 5 years of CHAMP measurements
of the period 09Aug2000 to Apr2005. The model is
given as a spherical harmonic expansion of the scalar magnetic potential
to degree 90. Coefficients 115 are set to zero, since these coefficients
are masked by the main magnetic field with its source in the Earth's
core.
See also the special model for ground level: MF4x
Improvements over MF3 (GFZ)
Data processing scheme for the MF4 model 
Available MF4 Downloads  

Type  Format  Mbyte  Ref.Radius  Contents  
SH coefficients  ASCII Table  0.2  6371.2 km  MF4 Model spherical harmonic coefficients (Schmid seminormalized, as usual)  
Graphic  0.5  6771.2 km  Image of Bz at average satellite altitude  
Graphic  0.8  6429.2 km  Image of Bz at 50 km above surface  
Graphic  0.7  6771.2 km  Image of total intensity anomaly (dT) at 400 km altitude  
Graphic  0.7  6429.2 km  Image of total intensity anomaly (dT) at 50 km above surface  
Graphic  0.6  6471.2 km  Image of analytic signal grad(dT) at 100 km altitude  
Graphic  0.6  6771.2 km  Image of analytic signal grad(dT) at 400 km altitude  
Data grid  ASCII Listing  20  6771.2 km  15' grid of Bz at average satellite altitude  
Data grid  ASCII Listing  20  6771.2 km  Total intensity anomaly (dT) at 400 km altitude  
Data grid  ASCII Listing  20  6429.2 km  Total intensity anomaly (dT) at 50 km above surface  
Data grid  ASCII Listing  21  6471.2 km  Analytic signal grad(dT) at 100 km altitude  
Data grid  ASCII Listing  22  6471.2 km  Northward derivative of dT at 100 km altitude  
Data grid  ASCII Listing  22  6471.2 km  Eastward derivative of dT at 100 km altitude  
Data grid  ASCII Listing  22  6471.2 km  Downward derivative of dT at 100 km altitude  
Data grid  ASCII Listing  20  6429.2 km  15' grid of Bz at 50 km above surface  
Animation  AVI  31  6471.2 km 
Simple animation of a rotating sphere with MF4 crustal anomalies
using Z at 100 km altitude, exaggerated as 3D and colored;
the smaller greyish structures are only bumpmap overlays of a
topographic/bathymetric map.
Runs in MS Powerpoint und Apple Quicktime 5.0.2, but not in MS Windows Media Player. Compression yields in a loss of image quality. 

= use with caution since noise is strongly amplified by downward continuation! 
2005Jun12, Stefan Maus, Martin Rother.