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- The objectives of the EFD investigation on Geotail are studies of (1) the large
scale configuration of the electric field in the magnetotail, (2) tail electric
field variations during substorms, (3) the electric field in the plasma sheet,
(4) the electric field near the magnetopause and in the plasma mantle at
locations tailward of those covered by similar measurements on ISEE 1, (5)
micropulsation and low frequency wave measurements at frequencies covering the
local gyrofrequency (<1Hz) and lower hybrid frequency (<10Hz) in the tail, (6)
plasma density as deduced from measurement of the floating potential of the
spacecraft, and (7) electric field comparisons (with the aid of the other
spacecraft in the ISTP program) at different points along the same magnetic
field line, at different points along a common boundary, or in different
regions of the magnetosphere.
The instrument consists of two orthogonal double probes, each of which is a
pair of separated spheres on wire booms that are located in the satellite spin
plane and whose difference of potential is measured. The separation distances
between the pair of sensors are variable and as great as 160 m tip-to-tip. One
operating mode involves length ratios of the two antennas of about 2:1 in order
to verify instrument operation through showing that the electric field
signature is proportional to the boom length. A second reason for two pairs of
wire booms in the satellite spin plane is the requirement for measurements
having a time resolution far better than the satellite spin period.
Principal Investigator:
Dr. Koichiro Tsuruda
The Institute of Space and Astronautical Science
3-1-1 Yoshinodai, Sagamihara
Kannagawa 229, Japan
Phone: 81-427-51-3911 ext. 2501
Fax: 81-427-59-4236
e-mail: tsuruda@fujitubo.gtl.isas.ac.jp
See:
"http://pwg.gsfc.nasa.gov/geotail_inst.shtml"
Group: Instrument_Details
Entry_ID: EFD
Group: Instrument_Identification
Instrument_Category: Solar/Space Observing Instruments
Instrument_Class: Magnetic Field/Electric Field Instruments
Short_Name: EFD
Long_Name: Electric Fields Detector (Geotail)
End_Group
Group: Associated_Platforms
Short_Name: GEOTAIL
End_Group
Online_Resource: http://pwg.gsfc.nasa.gov/geotail_inst.shtml#EFD
Online_Resource: http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1992-044A&ex=5
Group: Instrument_Logistics
Instrument_Start_Date: 1992-07-24
Instrument_Owner: ISAS, Japan
End_Group
End_Group
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