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Magnetometer (MAG)

NSSDCA ID: 2005-045A-07

Mission Name: Venus Express
Principal Investigator:Dr. Tielong Zhang

Description

The Magnetometer instrument (MAG), is designed to make measurements of magnetic field strength and direction. The scientific objectives of this experiment are to identify boundaries between the various plasma regions, study the interaction of the solar wind with the atmosphere of Venus and provide support data for measurements made by other instruments.

The magnetometer instrument consists of two tri-axial fluxgate magnetometers, one mounted on the outer surface of the spacecraft and one on the end of a 1 meter long deployable boom, and an electronic control unit. The use of two sensors reduces the effect of the intrinsic magnetic field of the spacecraft on the measurements. The fluxgate sensors each consist of two single ring-core sensors measuring the magnetic field in the X- and Y-directions. The magnetic field in the Z-direction is measured using a coil surrounding both the X- and Y- sensors. The side length of the cuboid sensor triad is approximately 50 mm. A feedback field is used to increase the overall linearity and stability of the magnetometer. It is supplied to all sensor elements by a separate pair of Helmholtz coils per sensor axis.

Sense and feedback signals are continuously transmitted to the digital processing unit, which calculates the magnetic field values with a resolution of 24 bits by scaling and summing the received data. The appropriate dynamic range is defined by selecting 16 of the calculated 24 bits for transmission. The measurement range can be modified by telecommand to have a value between +- 32.8 nT and +- 8 388.6 nT, with a corresponding digital resolution between 1 pT and 128 pT. The default range will be +- 262.1 nT with a resolution of 8 pT. A magnetic field of +- 10 000 nT can be independently applied to each sensor axis via additional 12-bit digital to analogue converters for compensation of any static stray field.

The MAG instrument will take measurements over the entire orbit. It has four operating modes which take data at 1 Hz, 2 Hz, 4 Hz, or 64 Hz. MAG is based on the Rosetta ROMAP instrument.

Alternate Names

  • MAG
  • VenusExpress/MAG

Discipline

  • Planetary Science: Fields and Particles

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams

 

Personnel

NameRoleOriginal AffiliationE-mail
Dr. Tielong ZhangPrincipal InvestigatorInstitut fuer Weltraumforschung, AustriaTielong.Zhang@oeaw.ac.at
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