PDS_VERSION_ID                   = PDS3
RECORD_TYPE                      = STREAM

OBJECT                           = DATA_SET
DATA_SET_ID                      = "LP-L-ENG-6-ATTITUDE-V1.0"

OBJECT                           = DATA_SET_INFORMATION
DATA_SET_NAME                    = "LP MOON SPACECRAFT ATTITUDE V1.0"
START_TIME                       = 1998-01-05
STOP_TIME                        = UNK
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 attitude data set consists of values for the
spacecraft spin rate and spin axis orientation (attitude) as a
function of time.  These values are determined from spacecraft
attitude data (sun and limb crossing sensors) and ephemeris data.  The
details as to how attitude and spin rate are determined are given in
the Project's Ground Software User's Guide and Programmer's Guide
[JACOBSEN1998].

Spacecraft orientations are given as right ascension and declination
of the spacecraft spin axis in the Mean-of-J2000 Ecliptic reference
frame.  The attitude data set consists of a single, cumulative file
for the entire mission.  Records are added to this file following each
significant change in either the spin rate or spin axis orientation.

The spacecraft spin rates and attitudes in this data set are orbit
averages.  The instantaneous spin rate can be determined from the sun
pulse data set.  The instantaneous spin rate varies as the spacecraft
passes into and out of the Moon's shadow and after each spacecraft
maneuver.  Generally, an attitude record is included for times
immediately before and after each maneuver.
 
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].  The spacecraft attitude and spin rate data
are used to determine the spacecraft orientation at the time science
data were acquired.  "
 
 CONFIDENCE_LEVEL_NOTE           = "
 
Confidence Level Overview
=========================

Spin rate is given as the orbit average rate of spin.  During eclipse,
the instantaneous spin rate may differ from the mean spin rate by up
to 0.01 revolutions per minute as the spacecraft passes into and out
of the Moon's shadow.

The uncertainty in spacecraft attitude (right ascension and
declination) is estimated to be about one degree of arc.  The
spacecraft attitude generally varies by less than one degree per day,
except during maneuvers.  No attempt is made to determine the
instantaneous spacecraft attitude during a maneuver.  Following a
maneuver, the spacecraft nutates for 6 to 8 hours.

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

Attitude and spin rate determinations exist for the entire Lunar
Prospector Primary Mission. "
 
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                    = ENG
 END_OBJECT                       = DATA_SET_HOST
  
 OBJECT                           = DATA_SET_REFERENCE_INFORMATION
 REFERENCE_KEY_ID                 = "BINDERETAL1998"
 END_OBJECT                       = DATA_SET_REFERENCE_INFORMATION
  
 OBJECT                           = DATA_SET_REFERENCE_INFORMATION
 REFERENCE_KEY_ID                 = "JACOBSEN1998"
 END_OBJECT                       = DATA_SET_REFERENCE_INFORMATION
  
END_OBJECT                        = DATA_SET
END