Vector Anomaly Component Values Covering 65 Deg South to 65 Deg North Latitude

Description

This data set contains the x (north), y (east), and z (down) components of the vector anomaly field, averaged over two- by two-degree areas from 65 degrees north to 65 degrees south latitude. There are four separate files: one for each rectangular component of the anomaly field, and one with a very short description of the data plus a Fortran program to read and print any file. The processing followed the same steps used for the Magsat scalar anomaly data set (79-094A-01M): (1) selection for magnetically quiet periods; (2) subtraction of the main field, estimated by the Magsat model field MGST(4/81); (3) subtraction of an estimated magnetospheric field; and (4) subtraction of a linear trend fit to the ("magnetospherically corrected") data from each pass. These data form the basis for the delta X, Y, and Z plots that appear as Figures 1 and 2 and the journal frontispiece in the paper "Initial vector magnetic anomaly map from Magsat," R. A. Langel et al., Geophysical Research Letters, v. 9, no. 4, pp. 273-276, 1982. That article should be consulted for details relating to the map generation. The vector anomaly maps are available as photographic prints in data set 79-094A-02R.