  Low-inclination, low altitude Earth orbits (LEO) are of increasing importance
for astrophysical satellites, due to their low background environment. Here,
the South Atlantic Anomaly (SAA) is the region with the highest amount of
radiation. We study the radiation environment in a LEO (500-600 km altitude, 4
degrees inclination) through the particle background measured by the Particle
Monitor (PM) experiment onboard the BeppoSAX satellite, between 1996 and 2002.
Using time series of particle count rates measured by PM we construct intensity
maps and derive SAA passage times and fluences. The low-latitude SAA regions
are found to have an intensity strongly decreasing with altitude and dependent
on the magnetic rigidity. The SAA extent, westward drift and strength vs
altitude is shown.
