Collection Information
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IDENTIFIER |
urn:nasa:pds:mess-mag-raw:data-lac::1.0
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NAME |
MESSENGER MAG Alternating Current Data Collection
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TYPE |
Data
|
DESCRIPTION |
Contains alternating current (AC) level values at the commanded sample rate. To conserve
telemetry the vector sampling will usually be less than the maximum rate, 20 sample/s.
To provide a record of the amplitude of fluctuations for frequencies higher than 1 Hz,
an AC amplitude is calculated from the internally sampled 20/s data for the sensor axis
commanded as the AC_AXIS. Thus, in addition to the vector samples data, a 1 Hz to 10 Hz
bandpass average amplitude is evaluated for the commanded sensor axis, selected by command,
and recorded as a log AC value with a 4-bit mantissa of the four most significant non-zero
bits and a 4-bit power of two exponent of the 4th (least significant) bit of the mantissa.
This is called the logAC value. It is created once per second and saved for telemetry at
that rate or at the commanded science rate, whichever is less frequent.
|
SEARCH/ACCESS DATA |
MESSENGER MAG Alternating Current Data Collection Online
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Citation |
DIGITAL OBJECT IDENTIFIER (DOI) |
10.17189/1522364
|
AUTHOR LIST |
Korth, H.
|
EDITOR LIST |
|
PUBLICATION YEAR |
2021
|
DESCRIPTION |
Contains alternating current (AC) level values at the commanded sample rate. To conserve
telemetry the vector sampling will usually be less than the maximum rate, 20 sample/s.
To provide a record of the amplitude of fluctuations for frequencies higher than 1 Hz,
an AC amplitude is calculated from the internally sampled 20/s data for the sensor axis
commanded as the AC_AXIS. Thus, in addition to the vector samples data, a 1 Hz to 10 Hz
bandpass average amplitude is evaluated for the commanded sensor axis, selected by command,
and recorded as a log AC value with a 4-bit mantissa of the four most significant non-zero
bits and a 4-bit power of two exponent of the 4th (least significant) bit of the mantissa.
This is called the logAC value. It is created once per second and saved for telemetry at
that rate or at the commanded science rate, whichever is less frequent.
|
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Context |
START DATE TIME |
2004-08-12T05:44:07.000Z
|
STOP DATE TIME |
2015-04-30T03:08:04.000Z
|
LOCAL MEAN SOLAR TIME |
|
LOCAL TRUE SOLAR TIME |
|
SOLAR LONGITUDE |
|
PRIMARY RESULT PURPOSE |
ENGINEERING
|
PRIMARY RESULT PROCESSING LEVEL |
Raw
|
PRIMARY RESULT DESCRIPTION |
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PRIMARY RESULT WAVELENGTH RANGE |
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PRIMARY RESULT DOMAIN |
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PRIMARY RESULT DISCIPLINE NAME |
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INVESTIGATION |
MESSENGER
|
OBSERVING SYSTEM |
|
OBSERVING SYSTEM COMPONENT |
MESSENGER
Magnetometer
|
TARGET |
CALIBRATION
EARTH
VENUS
MERCURY
|
REFERENCES |
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