Improved Models of the Inner and Outer Radiation Belts

Abstract

A pitch angle dependent invariant routine has been developed. This routine written in FORTRAN calculates the first and second invariant for an arbitrary number of pitch angles at any satellite location within the magnetosphere providing the observation is on a closed field line. The invariant routine utilizes a new fast version of the IGRF internal magnetic field and the Olson-Pfitzer 1977 external magnetic field routine. The internal field routine utilizes term dropping at large distances as well as improved coding techniques to obtain speed advantages of 1.5 to 35 over the standard internal field routine. The invariant utilizing routine is highly optimized and calculates all of the pitch angle dependent invariant utilizing only a single field line integral. The invariant routine also determines the actual minimum B value along the line of force and where in local time the field line crosses the magnetic equator. Hiton's expansion of L is used to assign an L value to each of the invariant calculations.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1991
Accession Number
ADA242579

Entities

People

  • K. A. Pfitzer

Tags

Communities of Interest

  • C4I
  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Altitude
  • Artificial Satellites
  • Atmospheres
  • Atmospheric Density
  • Cartesian Coordinates
  • Coordinate Systems
  • Hypervelocity Flow
  • Integrals
  • Latitude
  • Longitude
  • Magnetic Fields
  • Magnetosphere
  • Radiation
  • Space Sciences
  • Space Systems
  • Standards

Fields of Study

  • Physics

Readers

  • Calculus or Mathematical Analysis
  • Computer Science.
  • Space/Atmospheric Physics.

Technology Areas

  • Space
  • Space - Spacecraft Maneuvers