PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2003-08-19 NOTE = "Description of the GEOMETRY directory contents for the Lunar Prospector MAG/ER Level 1 data archive." END_OBJECT = TEXT END GEOMETRY Directory Contents The GEOMETRY directory contains ancillary geometry files for the Lunar Prospector data on this disk. The data includes spacecraft attitude, spin rate, and ephemeris. The following files are found in this directory. GEOMINFO.TXT - The file you are reading. ATTITUDE.TAB - A sparse table giving the time and new spacecraft orientation after each major change in spacecraft attitude or spin rate. Parameters are spin averaged. ATTITUDE.LBL - PDS label for ATTITUDE.TAB. The spacecraft ephemeris data in EME-50 coordinates are stored in the EME50 directory. These files have the naming convention: Eyyddd.DAT - Spacecraft ephemeris files where yyddd is the year and day of year for the start of a given file. Data contain spacecraft state vectors in Selenocentric Earth Mean Equatorial (1950) coordinates. Eyyddd.LBL - PDS label for Eyyddd.DAT. The spacecraft trajectory data are stored in the TRAJECT directory. These files have the naming convention: POSyy_mm.TAB - Spacecraft trajectory files where yy and mm are the year and month of a given file. Data contain spacecraft location vectors in a variety of coordinate systems. POSyy_mm.LBL - PDS label for POSyy_mm.TAB. The spacecraft Sun pulse data (binary) are stored in the SUNPULSE directory. These files have the naming convention: Syydddhh.B - Spacecraft sunpulse files where yydddhh is the year, day and hour for the start of a given file. Files contain spacecraft sunpulse times and time uncertainties. Syydddhh.LBL - PDS label for Syydddhh.B The attitude, position, spacecraft ephemeris, and sunpulse data files are part of the LP Level 0 archive prepared by the Geosciences Node of the PDS. These files are provided here to improve the usability of the Level 1B MAG and ER data on this disk. Some Level 0 files included here may have been padded with space characters prior to inclusion. The SPICE kernels are provided on this product for completeness and are not official NAIF data sets. The kernels represent the best data available from NAIF at the time of the creation of this product; however, each of these kernels is dynamic and is subject to updates with time. The official archive of all SPICE products is maintained by the Navigation and Ancillary Information Facility (NAIF) at the Jet Propulsion Laboratory (JPL) in Pasadena, CA. In addition to being the PDS archive site for the SPICE kernels, NAIF provides and maintains a software toolkit (SPICELIB) for accessing the kernels. For more information about NAIF or SPICELIB please visit the NAIF website (http://pds.jpl.nasa.gov/naif.html). LP_EPHEM.TSP - A SPICE spacecraft/planetary ephemeris kernel that contains ephemerides for the Earth, Moon, and Sun. This kernel can be used to generate LP trajectory data in alternative coordinate systems and to generate transformation matrices that can rotate the magnetometer data into these systems. This kernel is provided in transfer format. P_CONST.TPC A SPICE kernel containing planetary constants data in transfer format. LEAP_SEC.TLS A SPICE kernel containing leapsecond data in transfer format. The following file, though not a SPICE kernel, serves related purposes: MOON_POS.TAB A table of positions of the Moon relative to Earth. Each kernel is accompanied on the disk by a detached PDS label file, which has the same filename but with the extension replaced by .LBL. In addition to accessing geometry files directly, users with Web browsers can access them via links in the HTML file GEOMETRY.HTM in the EXTRAS directory, and can navigate the entire disk using the file AAREADME.HTM in the disk root directory.