Three L-Value Zones Demarking Belt Indices

To discriminate between regions of different geomagnetic particle trapping, three separate belt indices are calculated based on the L-value at the satellite's location. The inner zone, slot region and outer zone correpond to regions with an L-value less than 2.0, regions from 2.0 up to but not including 2.5, and regions greater than 2.5, respectively.