PDS_VERSION_ID                   = PDS3
LABEL_REVISION_NOTE              = "E. GUINNESS, 1998-09-04;
                                    E. GUINNESS, 1999-05-11;
                                    E. GUINNESS, 1999-10-01"

RECORD_TYPE                      = STREAM

OBJECT                           = DATA_SET
DATA_SET_ID                      = "LP-L-ENG/GRS/NS/APS/MAG/ER-1-MDR-V1.0"

OBJECT                           = DATA_SET_INFORMATION
DATA_SET_NAME                    = "LP MOON MERGED TELEMETRY DATA V1.0"
START_TIME                       = 1998-01-07T06:31
STOP_TIME                        = 1999-07-31T08:59
DATA_OBJECT_TYPE                 = "TABLE"
DATA_SET_RELEASE_DATE            = 1998-06-01
PRODUCER_FULL_NAME               = "ALAN B. BINDER"
DETAILED_CATALOG_FLAG            = "N"
DATA_SET_COLLECTION_MEMBER_FLG   = "N"
DATA_SET_DESC                    = "

Data Set Overview
=================

The Lunar Prospector merged telemetry data set is a result of
comparing the two Lunar Prospector telemetry data streams and
selecting one of them.  The Lunar Prospector raw telemetry data
downlink stream contained data transmitted in real-time and data that
was collected about 50 minutes prior and stored on the spacecraft.
The purpose of the delayed stream was to capture data acquired during
communications blackouts.  See the CONFIDENCE_LEVEL_NOTE field for a
description of the merging process.

The merged telemetry data set contains raw science and instrument
engineering data acquired by all of the science instruments (Gamma
Ray, Neutron, and Alpha Particle Spectrometers, and the Magnetometer
and Electron Reflectometer), along with spacecraft engineering data.
As such, the merged telemetry files are part of the Lunar Prospector
Level 0 data archive.  The data set is organized into binary files
with each file containing about 4-6 hours of data.  Each record in a
given file is a main (minor) frame containing 2 seconds of downlinked
data.  A major frame consists of 16 minor frames.
 
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; BINDER1998]. "
 
 CONFIDENCE_LEVEL_NOTE           = "
 
Confidence Level Overview
=========================

The merging process compared each minor frame of the real-time and
delayed data streams.  When mismatches occurred between the two data
streams, the data stream with the highest signal-to-noise ratio was
chosen for storage in the merged file.  When there were no mismatches,
the real-time data stream was chosen.  When mismatches occurred
between the two streams, and the signal-to-noise ratios were the same,
the real-time stream was selected.  Where there was only one data
stream for a given time, that stream was stored in the merged file.
Each minor frame (i.e., each record in a merged telemetry file) has a
flag to indicate which stream was selected and which criteria was used
for the selection.

Data Coverage and Quality
=========================

Science and engineering data were acquired continuously by the Lunar
Prospector science instruments during the Primary and Extended
Missions.  Over time, the entire lunar surface was covered from the
circular polar orbit of the spacecraft.  However, data gaps occurred
in the merged telemetry data files.  The times of these data gaps are
documented in a log file included with the level 0 archive.

Noise in several faces of the Alpha Particle Spectrometer (APS)
instrument caused data from the other faces to saturate.  The noise
was due to solar flares or other effects.  Faces of the APS showing
the most noise were turned off to keep the instrument from saturating.
Near the start of the Extended Mission, noise in the Alpha Particle
Spectrometer instrument started to affect the Neutron Spectrometer
(NS) causing the NS instrument to saturate.  As a result, the APS was
turned off on February 8, 1999 to allow the NS to collect clean data.
The APS instrument was turned on again on April 21, 1999 and was
collecting good data without noise in either the APS or NS. However,
noise from the APS began affecting the NS again in mid-May 1999.  As a
result, the APS was turned off on May 24, 1999 and it remained off for
the remainder of the mission.

All three spectrometers were turned off for the final three days of
the mission (July 28-31, 1999) in order to conserve battery power
during a lunar eclipse.  The MAG/ER instruments, however, continued to
operate right up to the time of impact."
 
 END_OBJECT                       = DATA_SET_INFORMATION

 OBJECT                           = DATA_SET_TARGET
 TARGET_NAME                      = MOON
 END_OBJECT                       = DATA_SET_TARGET
 
 OBJECT                           = DATA_SET_HOST
 INSTRUMENT_HOST_ID               = LP
 INSTRUMENT_ID                    = {GRS, NS, APS, MAG, ER}
 END_OBJECT                       = DATA_SET_HOST

 OBJECT                           = MISSION_REFERENCE_INFORMATION
   REFERENCE_KEY_ID               = "BINDER1998"
 END_OBJECT                       = MISSION_REFERENCE_INFORMATION
 
 OBJECT                           = DATA_SET_REFERENCE_INFORMATION
 REFERENCE_KEY_ID                 = "BINDERETAL1998"
 END_OBJECT                       = DATA_SET_REFERENCE_INFORMATION

END_OBJECT                        = DATA_SET
END