This data set contains the 286 coefficients of the POGO (10/68) spherical harmonics model of the Earth's main (core) magnetic field. The coefficients are for epoch 1960.0 and extend up to degree and order 11 in the constant and first derivative terms. In addition to all the data used in POGO (3/68), the model is based on OGO 4 field strength data until December 1967. Altogether 32,649 data points were considered in establishing POGO (6/68). Improvements over POGO (3/68) resulted not only from the extended data base but also from using more accurate orbital positions for OGO 2.
J. C. Cain and R. A. Langel, The Geomagnetic Survey by the Polar-Orbiting Geophysical Observatories OGO 2 and OGO 4 1965-1967, Goddard Space Flight Center, Report X-612-68- 502, Greenbelt, Maryland, 1968.