Data Set Information
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| DATA_SET_NAME |
LP MOON SUN PULSE DATA V1.0
|
| DATA_SET_ID |
LP-L-ENG-6-SUNPULSE-V1.0
|
| NSSDC_DATA_SET_ID |
|
| DATA_SET_TERSE_DESCRIPTION |
|
| DATA_SET_DESCRIPTION |
Data Set Overview : The sun pulse data set is a record of times that the Lunar Prospector sun sensor detects the Sun. These sun pulse times are derived from ground processing of the sun sensor data, earth-moon limb sensor data, and the spacecraft ephemeris. This data set is part of the Lunar Prospector Level 0 data archive. The sun pulse times are used in determining the spacecraft spin rate and orientation as a function of time. Because the Lunar Prospector spacecraft is sometimes in eclipse with the Sun, the sun pulse data set is generated on the ground to include both actual sun pulse times based on the sun sensor measurements and estimated sun pulse times based on the history of spin rate change during all prior eclipses. See the CONFIDENCE_LEVEL_NOTE field for further information on how sun pulse time is estimated during eclipses. The sun pulse data set is organized into files, each of which cover about 4-6 hours of time. In general, each sun pulse file matches the time range of a corresponding merged telemetry file. There is usually one sun pulse record for every other minor frame of the merged telemetry file. Science Objectives : The Lunar Prospector science objectives relevant to this data set are to map the Moon's surface composition and its magnetic field, and to determine the frequency and location of gas release events. A special emphasis of the science objectives is to search for polar water ice deposits [BINDERETAL1998].
|
| DATA_SET_RELEASE_DATE |
1998-06-01T00:00:00.000Z
|
| START_TIME |
1998-01-07T09:36:00.000Z
|
| STOP_TIME |
1999-07-29T06:10:00.000Z
|
| MISSION_NAME |
LUNAR PROSPECTOR
|
| MISSION_START_DATE |
1995-01-01T12:00:00.000Z
|
| MISSION_STOP_DATE |
1999-07-31T12:00:00.000Z
|
| TARGET_NAME |
MOON
|
| TARGET_TYPE |
SATELLITE
|
| INSTRUMENT_HOST_ID |
LP
|
| INSTRUMENT_NAME |
LP ENGINEERING
|
| INSTRUMENT_ID |
ENG
|
| INSTRUMENT_TYPE |
UNKNOWN
|
| NODE_NAME |
Planetary Plasma Interactions
|
| ARCHIVE_STATUS |
ARCHIVED
|
| CONFIDENCE_LEVEL_NOTE |
Confidence Level Overview : When Lunar Prospector was in sunlight, the sun pulse time was set equal to the sun sensor time extracted from the telemetry files. When the spacecraft was in eclipse, the sun pulse was estimated using the pre-eclipse measured spin rate, the calibrated spin rate change during eclipse, and limb sensor telemetry. The uncertainty in an estimated sun pulse time was also determined and stored in the data set. Each sun pulse record contains a flag indicating whether the value is an actual or estimated value. Data Coverage and Quality : Sun sensor data were acquired continuously by Lunar Prospector during the Primary and Extended Missions. However, gaps can occur in the telemetry data. The times of these gaps are documented in a log file included with the level 0 archive. There were 18 sun pulse files missing from the archive volume that contained the matching telemetry file because solutions were not complete at the time the archive volume was produced. The missing sun pulse files are included on the last level 0 volume (LP_0019) in the SUNPULSE/DXXX directory. The 18 late sun pulse files are documented in the ERRATA.TXT file. The earth-moon limb sensor was turned off toward the end of the Primary Mission and into the Extended Mission to extend the spacecraft battery life. Thus these data were not always available for estimating sun pulses during times of spacecraft eclipses.
|
| CITATION_DESCRIPTION |
Binder, A.B., W.C. Feldman, A.S.Konopliv, R.P. Lin, M.H. Acuna, L.L. Hood, and E.A. Guinness, LP MOON SUN PULSE DATA V1.0, LP-L-ENG-6-SUNPULSE-V1.0, NASA Planetary Data System, 1998.
|
| ABSTRACT_TEXT |
The sun pulse data set is a record of times that the Lunar Prospector sun sensor detects the Sun. These sun pulse times are derived from ground processing of the sun sensor data, earth-moon limb sensor data, and the spacecraft ephemeris. This data set is part of the Lunar Prospector Level 0 data archive. The sun pulse times are used in determining the spacecraft spin rate and orientation as a function of time. Because the Lunar Prospector spacecraft is sometimes in eclipse with the Sun, the sun pulse data set is generated on the ground to include both actual sun pulse times based on the sun sensor measurements and estimated sun pulse times based on the history of spin rate change during all prior eclipses.
|
| PRODUCER_FULL_NAME |
ALAN B. BINDER
|
| SEARCH/ACCESS DATA |
Planetary Plasma Interactions Website
Geosciences Web Services
Geosciences Online Archives
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