Abstract: A modified hybrid Hall effect device is provided which is the combination of a conventional Hall effect device and a second Hall effect device having a Hall plate coupled to a ferromagnetic layer. The hybrid Hall effect device can be used to determine the independent magnetic field vector components comprising a vector magnetic field, such as for determining the {circumflex over (x)} and the {circumflex over (z)} components of a magnetic field, or for measuring the total magnitude of a vector magnetic field of any orientation. The modified Hall Effect device can be adapted for use as a magnetic field sensor for the detection of macroscopic objects that have associated magnetic fields, or for microscopic objects that have been tagged by microscopic magnetic particles.

Abstract: An aspect of the present invention is a method and apparatus for computing a geomagnetic transmission function. This apparatus includes a programmed digital computer running modeling software for modeling the transmission of cosmic ray particles through the magnetosphere. The software includes a model representing a solution to the Lorentz equation in a magnetic field given by B=BIGRF(r,t?)+BTSYG(Kp,r,t?). Another aspect of the present invention is a method and apparatus for computing a flux of particles at the outer surface of a satellite comprising, inter alia, an improved method and apparatus for computing a flux of solar heavy ions. This apparatus includes a programmed digital computer running modeling software for modeling the flux of cosmic ray particles through the outer surface of a satellite.