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Advanced Composition Explorer Level 2 ASCII Magnetic Field Data, 1-hour Vectors


Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1997-12-27 to 2000-10-17


This data collection contains Level 2 data files in ascii format from the magnetometer experiment on the Advanced Composition Explorer (ACE) spacecraft. Each file contains data from one Bartel interval of 27 days at a time resolution for individual records of one hour. Components of the interplanetary magnetic field vectors are given in heliographic (RTN) and Geocentric Solar Ecliptic (GSE) coordinates in units of nanotelsa (nT). Other parameters include the scalar magnitude, RTN longitude angle (Lambda), RTN latitude angle (Delta), RMS deviations of measured vector components at 16-sec resolution from the average values, and the variance of the scalar magnitude. The fraction of the averaging interval during which there was good quality data, and the number of 16-sec intervals (1) used to generate the average, are also included. Errors in magnetic field parameters are generally less than 0.1 nT. Spacecraft position is provided in GSE coordinates. Data values of -999.9 indicate bad or missing data for the given time period. Level 2 format documentation and release notes on processing are respectively included in the text files mag_l2desc.txt and mag_release_notes.txt.

Data are available online at

Alternate Names

  • MAG Level 2 ASCII,1-hour Vectors


  • Space Physics: Heliospheric Studies


  • 97-045A-09H

Additional Information



Questions and comments about this data collection can be directed to: Dr. John F. Cooper



NameRoleOriginal AffiliationE-mail
Dr. Andrew J. DavisGeneral ContactCalifornia Institute of
Mr. Robert M. CandeyGeneral ContactNASA Goddard Space Flight
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