Data Set Information
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| DATA_SET_NAME |
LRO LUNAR EXPLORATION NEUTRON DETECTOR 2 EDR V1.0
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| DATA_SET_ID |
LRO-L-LEND-2-EDR-V1.0
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| NSSDC_DATA_SET_ID |
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| DATA_SET_TERSE_DESCRIPTION |
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| DATA_SET_DESCRIPTION |
Data Set Overview : The Lunar Reconnaissance Orbiter (LRO) Lunar Exploration Neutron Detector (LEND) that will act as large orbital neutron telescope for mapping the Moon's neutron albedo. LEND consists of eight 3He sensors for detecting thermal and epithermal neutrons, four of which are are collimated to improve spatial resolution. LEND also contains the Sensor for High Energy Neutrons (SHEN), which is a stilbene scintillator that produces a flash of light each time a high energy neutron in the energy range 0.3 - 15.0 MeV collides with a hydrogen nucleus and creates a recoil proton. A full description of the LRO LEND instrument can be found in [MITROFANOVETAL2008]. The LRO LUNAR EXPLORATION NEUTRON DETECTOR 2 EDR data set is a time series collection of science and housekeeping data from the LRO spacecraft. Data are sorted by type and by time. Data are sorted by time, with each data file containing one day's worth of data from midnight to midnight UTC. Measurements are assigned to a particular day based on the end of the collection interval. LEND collects a new spectrum (frame) approximately every second. Approximately 86400 spectra are expected to be received every day. The collection interval can be changed in the middle of a time series file, which can be determined by noting the difference between record timestamps. The data (both science and housekeeping) are downloaded from the spacecraft. Data are output to a spooler that passes them to the University of Arizona (UA) database ingest process. The ingest process inputs raw data into the UA database. Data are retrieved from the UA database to build the LEND EDR data products. The LEND EDR data set is intended to be the lowest level (level 0) data available for LEND. It should be useful to those scientists who are experienced in neutron spectroscopy. Parameters : The LEND EDR data set is composed of two data types. The objective of compiling the LEND EDR is to create a record of the primary data collected by LEND. The following paragraphs discuss the parameters of interest in each of the data types. Science ------- The LEND SCI data are time series science records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts 1 second. Data includes spectra for all collimated and uncollimated 3He detectors as well as spectra for the stilbene high energy neutron detector. Housekeeping ------------ The housekeeping data are time series records for each housekeeping parameter taken over the course of a day. Individual records are a single data collection interval. Data includes command, voltage and temperature information. Processing : A process termed 'ingest' occurs on the LEND Science Operations Center computer which receives data from the LRO Mission Operation Center. The ingest process verifies the consistency of the data. The LEND EDR data product is output by software that maps the stored relational data into the format described by the LEND EDR SIS. Both processes (ingest and output) are rigorously tested. Multiple versions of the data product may be made available if software bugs affecting the output data are uncovered and corrected. In the event of an error whose fix changes released data, it is expected the data will be reprocessed by the revised software and made available. Data : The LEND EDR data product contains two types of data. LEND_SCI_DATA Neutron Detector science data LEND_HK_DATA Neutron Detector housekeeping data LEND_SCI_DATA is a time series of Neutron Detector science data. LEND_HK_DATA is a time series of Neutron Detector housekeeping data. Each product type is stored in a separate file with a detached PDS label. All the product types are stored as binary tables with fixed-length records. Coordinate System : Not applicable for this data set. Software : No LEND specific software is provided with this data set. PDS-labeled images and tables can be viewed with the program NASAView, developed by the PDS and available for a variety of computer platforms from the PDS web site http://pds.nasa.gov/tools/software_download.cfm. There is no charge for NASAView. Media/Format : The LEND EDR will be delivered using DVD media. Formats will be based on standards for such products established by the Planetary Data System (PDS) [PDSSR2006].
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| DATA_SET_RELEASE_DATE |
2010-03-15T00:00:00.000Z
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| START_TIME |
2009-01-01T12:00:00.000Z
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| STOP_TIME |
N/A (ongoing)
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| MISSION_NAME |
LUNAR RECONNAISSANCE ORBITER
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| MISSION_START_DATE |
2009-06-18T12:00:00.000Z
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| MISSION_STOP_DATE |
N/A (ongoing)
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| TARGET_NAME |
MOON
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| TARGET_TYPE |
SATELLITE
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| INSTRUMENT_HOST_ID |
LRO
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| INSTRUMENT_NAME |
LUNAR EXPLORATION NEUTRON DETECTOR
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| INSTRUMENT_ID |
LEND
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| INSTRUMENT_TYPE |
CALORIMETER/SPECTROMETER
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| NODE_NAME |
Geosciences
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| ARCHIVE_STATUS |
ARCHIVED_ACCUMULATING
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| CONFIDENCE_LEVEL_NOTE |
Confidence Level Overview : The data presented in the LEND EDR is intended to be the least processed, most primitive data set released for LEND. Data presented here are an accurate representation of LEND data as received from the spacecraft. Review : The LEND EDR was reviewed internally by the LEND team prior to release to the PDS. PDS will also performed an external peer review of the LEND EDR. Data Coverage and Quality : Data reported are the minimally processed data received from the orbiter during nominal LEND operations. All data received is reformatted into one of the EDR data types. Data are by definition of good quality, as damaged telemetry packets are sequestered upon receipt from the spacecraft. We do not expect to receive many (if any) damaged data packets. Limitations : The major limitation of this data set is that this is level 0, minimally processed data. The data are received from the spacecraft telemetry and ingested into a database. If gaps exist in the telemetry, data are lost. Data Compression : No data compression is used.
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| CITATION_DESCRIPTION |
Boynton, W.V., 2009 Lunar Reconnaissance Orbiter Lunar Exploration Neutron Detector EDR Data V1.0, LRO-L-LEND-2-EDR-V1.0, NASA Planetary Data System, 2009.
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| ABSTRACT_TEXT |
Raw, uncalibrated housekeeping and scientific data collected from the Lunar Exploration Neutron Detector (LEND) aboard the Lunar Reconnaissance Orbiter.
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| PRODUCER_FULL_NAME |
WILLIAM BOYNTON
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| SEARCH/ACCESS DATA |
Geosciences Web Service
Geosciences Online Archives
Lunar Orbital Data Explorer
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