Data Description

This page summarizes information about the selected resource and its origin based on SPASE metadata.

Table of Contents

  1. Product
  2. Repository
  3. Instrument
  4. Observatory
  5. Persons

SPASE version 2.0.0

Numerical Data Product: Geotail KP Magnetic Field Data (64s)

Resource ID
spase://VMO/NumericalData/Geotail/MGF/PT64S Get XML
Name
Geotail KP Magnetic Field Data (64s)
Description

This data set contains the investigator-selected Key Parameters from the Magnetic Field instrument (MGF) on Geotail, as made available via NSSDC's interactive WWW interface CDAWeb.

Selected references:

Kokubun, S., et al., Magnetic field measurement (MGF), In Geotail Prelaunch Report, SES-TD-92-007SY, Institute of Space and Astronautical Science, SES Data Center, pp. 58-70, Apr. 1992.

Nishida, A., et al., Geotail mission to explore earth's magnetotail, EOS, 73, No. 40, Oct. 1992.

Kokubun, S., et al., The GEOTAIL Magnetic Field Experiment, J. Geomag. Geoelectr., 46, No. 1, 7-21, 1994.

Additional information
The Geotail Magnetic Field Experiment (MGF)

Reprint of Kokubun, S., T. Yamamoto, M. H. Acuna, K. Hayashi, K. Shiokawa, and H. Kawano, The Geotail Magnetic Field Experiment, J. Geomag. Geoelectr., 46, 7-21, 1994.

Key Parameters GE_K0_MGF from the Geotail Magnetic Field Instrument (MGF) in CDF
Acknowledgement

Data were provided by T. Nagai at Institute of Space and Astronautical Science, JAXA in Japan.

Contact
Role Person
1. Principal investigator Prof. Tsugunobu Nagai Get XML
2. Scientist Dr. Donald H. Fairfield Get XML
3. Metadata contact Jan Merka Get XML
Release date
2009-05-20 23:06:12
Repository
Name
CDAWeb Data Repository FTP Interface Get XML
Availability
Online
Access rights
Open
URL
CDAWeb FTP download
Format
CDF
Encoding
None
Instrument
Geotail MGF Get XML
Measurement type
Magnetic field
Temporal description
Start date
1992-09-04 19:14:06
Relative stop date
Cadence
1 minute 4 seconds
Observed regions
Earth.Magnetosheath
Earth.Magnetosphere
Earth.Magnetosphere.Magnetotail
Heliosphere.NearEarth
Caveats

Switched from outer magnetometer to inner in January 2007.

This data is computed with a preliminary algorithm and is not necessarily complete nor is it certified by the experimenters or considered publishable.

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Parameters

Parameter #1

Name
Time
Parameter key
Epoch
Description

Time in miliseconds since CDF epoch

Units
ms
Conversion to SI units
1e-3>s
Valid minimum
01-Aug-1992 00:00:00.000
Valid maximum
31-Dec-2000 23:59:59.000
Fill value
-1.0E31
Parameter type
Temporal

Parameter #2

Name
Time
Parameter key
Time_PB5
Description

Time as an array (year, day of year and elapsed milliseconds of day).

Structure
Size
3
Elements
Index Name Units Valid min Valid max Fill value
1 Year year 1992 2020 -2147483648
2 Day of Year (jan 1 = day 1) day 1 366 -2147483648
3 Elapsed ms of day ms 0 86399000 -2147483648
Parameter type
Temporal

Parameter #3

Name
Time of day
Parameter key
MSEC
Description

Elapsed milliseconds of day

Units
ms
Valid minimum
0
Valid maximum
86400000
Fill value
-2147483648
Parameter type
Temporal

Parameter #4

Name
Magnetic Field Intensity
Parameter key
IB
Description

Observed magnetic field intensity

Units
0.1nT
Conversion to SI units
1e-10>T
Valid minimum
-32768
Valid maximum
32767
Fill value
-32768
Quantity
Magnetic field
Qualifier
Average
Magnitude

Parameter #5

Name
Magnetic Field (GSE)
Parameter key
IB_vector
Description

Observed magnetic field vector in GSE coordinates

Units
0.1nT
Conversion to SI units
1e-10>T
Coordinate system
Cartesian GSE
Structure
Size
3
Elements
Index Name Component Valid min Valid max Fill value
1 Bx I -32768 32767 -32768
2 By J -32768 32767 -32768
3 Bz K -32768 32767 -32768
Quantity
Magnetic field
Qualifier
Average
Vector

Parameter #6

Name
B RMS (sensor coord)
Parameter key
IS_vector
Description

Standard deviation of sin fitting for magnetic field in sensor coordinates

Units
0.01nT
Conversion to SI units
1e-11>T
Coordinate system
Cartesian SC
Structure
Size
3
Elements
Index Name Component Valid min Valid max Fill value
1 Bx-RMS I -32768 32767 -32768
2 By-RMS J -32768 32767 -32768
3 Bz-RMS K -32768 32767 -32768
Quantity
Magnetic field
Qualifier
Standard deviation
Vector

Parameter #7

Name
MGF Range
Parameter key
RANGE_STATUS
Description

Range status of the fluxgate magnetometer.

  • 0 = Not valid
  • 1 = +/- 16 nT
  • 2 = +/- 64 nT
  • 3 = +/- 256 nT
  • 4 = +/- 1024 nT
  • 5 = +/- 4096 nT
  • 6 = +/- 16384 nT
  • 7 = +/- 65536 nT
Valid minimum
1
Valid maximum
7
Fill value
-32768
Parameter type
Other

Parameter #8

Name
Satellite Position (GSE)
Parameter key
POS
Description

Satellite position vector in GSE coordinates

Units
km
Conversion to SI units
1e3>m
Structure
Size
3
Elements
Index Name Component Valid min Valid max Fill value
1 X-GSE I -1800000.0 1800000.0 -1.0E31
2 Y-GSE J -1800000.0 1800000.0 -1.0E31
3 Z-GSE K -1800000.0 1800000.0 -1.0E31
Parameter type
Positional

Parameter #9

Name
Data Quality Flag
Parameter key
DQF
Description

Data quality flag: Good/Bad/Fill (0: good; 1,2,3: poor 4: fill value)

Valid minimum
0
Valid maximum
4
Fill value
-2147483648
Parameter type
Other

Parameter #10

Name
Post Gap Flag
Parameter key
Gap_Flag
Description

Post gap flag. 0: no gap occurred; 1: gap occurred because SIRIUS data were illegal or because the instrument was not in a mode that allowed KP's 2: gap occurred because of the jump of MGF RANGE or MGF SENSE during 64 s

Valid minimum
0
Valid maximum
2
Fill value
-2147483648
Parameter type
Other
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SPASE version 2.0.0

Instrument: Geotail MGF

Instrument ID
spase://SMWG/Instrument/Geotail/MGF Get XML
Name
Geotail MGF
Description

The objective of this experiment is to measure the magnetic field variation of the magnetotail in the frequency below 50 Hz. The MGF experiment consists of dual three-axis fluxgate magnetometers and a three-axis search coil magnetometer. Triad fluxgate sensors, which utilize a ring core geometry, are installed at the end and middle of a 6 m deployable mast. Three search coils are mounted approximately one-half of the way out on another 6 m boom together with search coils for the VLF wave in the PWI system.

The fluxgate magnetometers are of standard design and consist of an amplifier, filter, phase sensitive detector, integrator, and a voltage-current convertor. The fluxgate magnetometers operate in seven dynamic ranges to cover various regions of the Earth's magnetosphere and the solar wind: +/-16 nT, +/-64 nT, +/-256 nT, +/-1024 nT, +/-4096 nT, +/-16384 nT, and +/-65536 nT, and supply 16 vectors/sec.

The automatic range control of the fluxgate magnetometers failed in 1999 so the observable range was manually fixed in the +/-256 nT where it has remained ever since. On November 23, 2006, the fluxgate magnetometer at the end of the boom failed and data from the second magnetometer at the middle of the boom has been used ever since. Neither of the above changes substantially affect the data.

The search coil magnetometer system consists of three sensors, preamplifier, amplifier, filter, multiplexer, and an A/D converter. The search coil magnetometers operate in a frequency range of 0.5 kHz to 1 kHz, and supply 128 vectors/sec. The fluxgate magnetometer operates in both real time and record modes, while the search coil data are used only in real time mode.

Additional information
NSSDC's Master Catalog

Information about the Magnetic Fields Measurement (MGF)

Contact
Role Person
1. Principal investigator Prof. Tsugunobu Nagai Get XML
2. Scientist Dr. Donald H. Fairfield Get XML
3. Metadata contact Jan Merka Get XML
Release date
2009-05-20 21:10:15
Prior ID
spase://nssdc/instrument/1992-044A-06
Instrument type
Magnetometer
Investigation name
MGF on GEOTAIL
Observatory
Geotail Get XML
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SPASE version 2.0.0

Observatory: Geotail

Observatory ID
spase://SMWG/Observatory/Geotail Get XML
Name
Geotail
Alternate name
1992-044A
GTL
ISTP/Geotail
GGS/Geotail
Geomagnetic Tail Lab
Description

The solar wind draws the Earth's magnetic field into a long tail on the nightside of the Earth and stores energy in the stretched field lines of the magnetotail. During active periods, the tail couples with the near-Earth magnetosphere, sometimes releasing energy stored in the tail and activating auroras in the polar ionosphere.

The Geotail mission measures global energy flow and transformation in the magnetotail to increase understanding of fundamental magnetospheric processes. This includes the physics of the magnetopause magnetospheric boundary regions, the lobe and plasma sheet, and reconnection and neutral line formation, i.e., the mechanisms processes of input, transport, storage, release and conversion of mass, momentum and energy in the magnetotail.

Geotail, together with Wind, Polar, SOHO, and Cluster projects, constitute a cooperative scientific satellite project designated the International Solar Terrestrial Physics (ISTP) program which aims at gaining improved understanding of the physics of solar-terrestrial relations.

Geotail is a spin-stabilized spacecraft utilizing mechanically despun antennas with a design lifetime of about four years. The nominal spin rate of the spacecraft is about 20 rpm around a spin axis maintained between 85-89 degrees to the ecliptic plane. Geotail is cylindrical, approximately 2.2 m in diameter, and 1.6 m high. with It has body-mounted solar cells. Geotail also has and a back-up battery subsystem which that operates when the spacecraft is in the Earth's shadow (limited to 2 hrs). Real-time telemetry data transmitted in X-band are received at the Usuda Deep Space Center (UDSC) in Japan. There are two tape recorders on board, each with a capacity of 450 Mb, which allows daily 24-hour data coverage and are collected in playback mode by the NASA Deep Space Network (DSN).

The Geotail mission is divided into two phases. During the two-year initial phase, the orbit apogee was kept on the nightside of the Earth by using the Moon's gravity in a series of double-lunar swing-by maneuvers that result in the spacecraft spending most of its time in the distant magnetotail (maximum apogee about 200 Earth radii) with a period varying from one to four months. Then, in November 1994, there were a series of maneuvers that reduced the apogee to 50 Re. After three more months in the magnetotail the spacecraft was put in a 10 by 30 Re orbit where it has remained except that the perigee was reduced from 10 to 9 Re in June 1997.

Details on the Geotail mission and instrumentation are given in the Journal of Geomagnetism and Geoelectricity (Vol. 46, No. 1, 1994); online from JGG at

http://www.terrapub.co.jp/journals/EPS/JGG

Additional information
NSSDC's Master Catalog

Information about the Geotail mission

Contact
Role Person
1. Project scientist Guan Le Get XML
2. Project scientist Prof. Masaki Fujimoto Get XML
3. Metadata contact Jan Merka Get XML
Release date
2009-05-20 20:00:12
Location
Region
Earth.Magnetosphere
Heliosphere.NearEarth
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SPASE version 2.0.0

Person: Prof. Tsugunobu Nagai

Name
Prof. Tsugunobu Nagai
Organization
Tokyo Institute of Technology
Address
Department of Earth and Planetary Sciences, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
Email
nagai@geo.titech.ac.jp
Fax number
+81-3-5734-3537
Person ID
spase://SMWG/Person/Tsugunobu.Nagai Get XML
Release date
2009-03-16 21:51:28
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SPASE version 2.0.0

Person: Dr. Donald H. Fairfield

Name
Dr. Donald H. Fairfield
Organization
GSFC-Code 695
Email
u2dhf@lepdhf.gsfc.nasa.gov
Phone
+1-301-286-7472
Person ID
spase://SMWG/Person/Donald.H.Fairfield Get XML
Release date
1999-08-18 00:00:00
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SPASE version 2.0.0

Person: Jan Merka

Name
Jan Merka
Organization
NASA Goddard Space Flight Center
Address
Code 672, Greenbelt, MD 20771, USA
Email
jan.merka@nasa.gov
Phone
1-301-286-8751
Person ID
spase://SMWG/Person/Jan.Merka Get XML
Release date
2007-08-09 22:02:24
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SPASE version 2.0.0

Person: Dr. Robert E. McGuire

Name
Dr. Robert E. McGuire
Organization
NASA Goddard Space Flight Center
Address
Code 672, Greenbelt, MD 20771, USA
Email
mcguire@mail630.gsfc.nasa.gov
Phone
1-301-286-7794
Person ID
spase://SMWG/Person/Robert.E.McGuire Get XML
Release date
2007-05-30 15:25:24
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SPASE version 2.0.0

Person: Guan Le

Name
Guan Le
Organization
NASA Goddard Space Flight Center
Address
Code 674, Greenbelt, MD 20771, USA
Email
guan.le@nasa.gov
Phone
+1-301-286-1087
Person ID
spase://SMWG/Person/Guan.Le Get XML
Release date
2007-08-28 20:26:51
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SPASE version 2.0.0

Person: Prof. Masaki Fujimoto

Name
Prof. Masaki Fujimoto
Organization
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
Address
3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan
Email
fujimoto@stp.isas.jaxa.jp
Fax number
+81-42-759-8456
Person ID
spase://SMWG/Person/Masaki.Fujimoto Get XML
Release date
2009-03-23 19:02:01
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SPASE version 1.2.0

Repository: CDAWeb Data Repository FTP Interface

Repository ID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb Get XML
Name
CDAWeb Data Repository FTP Interface
Description

Coordinated Data Analysis Web (CDAWeb) supports not only interactive plotting of variables from multiple instruments on multiple investigations simultaneously on arbitrary, user-defined time-scales. It also supports data retrieval in various formats using its interactive web interface or ftp service.

Additional information
CDAWeb Home Page

Coordinated Data Analysis Web (CDAWeb) home page at Space Physics Data Facility of the NASA Goddard Space Flight Center.

Contact
Role Person
1. Project scientist Dr. Robert E. McGuire Get XML
Release date
2008-08-26 21:14:34
Prior ID
spase://VMO/Repository/CDAWeb
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