Data Set Overview : The Lunar Reconnaisance Orbiter (LRO) Radio Science (RS) Raw Data Archive (RDA) is a time-ordered collection of raw and partially processed data collected during the LRO mission to the Moon [CHINETAL2007] [SMITHETAL2009].  This data set was collected beginning in June 2009 after the launch of LRO.  Radio Doppler and range tracking to the LRO omnidirectional and high-gain antennas (HGA) provide the main source of the radio science data. The gimbaled HGA also carries a small, coboresighted, optical receiver telescope. One-way time-of-flight from the ground to the optical receiver using laser pulses provides an alternate tracking data type known as Laser Ranging (LR), which is handled jointly by the Lunar Orbiter Laser Altimeter (LOLA) Science Operations Center (SOC) and the Crustal Dynamics Data Information System (CDDIS).  The data set includes one primary data type, the tracking data files, TRKs.  Typical users of these data might analyze range and Doppler measurements in TRKs to reconstruct the spacecraft trajectory.  Users may obtain SPICE kernels related to pointing information of the solar array and high gain antenna at the JPL NAIF website: naif.jpl.nasa.gov/pub/naif/pds/data/lro-l-spice-6-v1.0/  Data : The Station Raw Tracking Data (TRK) provides the data required to support tracking of the orbiter and generation of orbit and mission products. Each ground station (WS1 and the USN stations) that supports tracking for the LRO mission will create the data in a format identified as the Universal Tracking Data Format (UTDF) as defined in the STDN Tracking and Acquisition Handbook [STDN7241990]. TRKs are stored in the TRK directory. File names are of the form LSUTDF_SSSSVV_PAD_YYYY_DDD_HHMM.ext, where File Qualifier :> 6 ASCII characters to identify the type of UTDF data LSUTDF (indicates low-speed UTDF data) Spacecraft Designations :> 6 ASCII characters (SSSSVV) to identify the spacecraft SSSS : Spacecraft ID (0059 for LRO) VV : Vehicle ID (01 for LRO) Receiver PADID :> 3ASCII characters (PAD) to identify the station receiver PAD identifier 188 for the White Sands station 189 for the Solar Dynamics Observatory (SDO) Backup station 103 for USPS for USN Dongara 105 for USHS for USN South Point, Hawaii 126 for KU1S (or KU2S) for Kiruna, Sweden 128 for WU1S (or WU2S) for Wilheim, Germany Date Information :> 13 ASCII characters in the form of YYYY_DDD_HHMM to represent the date and time of when the station closed the file; YYYY : 4 ASCII characters for year (2008 - 2013) DDD : 3 ASCII characters for day of year (001 - 366) HHMM : 4 ASCII characters (24 Hour time qualifier) ext :> 3-character ASCII extension; TRK (default)  The TRK PDS label has file names of the same form as the data files with an extension of LBL.  Secondary Data : A set of ancillary files is needed for proper analysis and interpretation of the TRK data.  Small Forces File (SFF Directory) --------------------------------- The Small Forces File (SFF) or Angular Momentum Desaturation (AMD) data provides the cumulative delta-V effect of attitude thruster firings over one or more specified intervals of time. In some cases it also provides an estimate of the cumulative spacecraft mass loss due to the use of propellant in those attitude thrusters. The same format file is also produced to model predicted accelerations. The primary data portion of a SFF consists of required parameters (in this order) separated by commas: Record index, record type, record generation time, data start time, data stop time, data accumulation period duration, mass change, resultant delta-V in J2000 X direction, resultant delta-V in J2000 Y direction, and resultant delta-V in J2000 Z direction. The secondary data portion is optional and consists of additional data requested by mission, for LRO this is TBD.  Weather Data Files (WEA Directory) ---------------------------------- The Weather data are ASCII formatted, space-delimited, information sent in a file format. Weather data files are produced at the ground stations. The file consists of multiple lines in which the first line contains start date (YYYYMMDD), Day of Year (DDD), and station identifier information. Then there are 2:N repeating lines that provide the following information: Time reference, temperature, Pressure, Relative Humidity, and Wind Speed  File names have the form STID_YYYYDDD_HHMM.ext, where: Station ID :> 4 ASCII Characters for the station ID WS1S : White Sands USPS : USN Dongara USHS : USN Hawaii KI3S : Kiruna, Sweden WG1S : Wilheim, Germany Scheduled Acquisition of Signal (AOS) time :> 12 ASCII characters in the form of YYYYDDD_HHMM, where: YYYY : start year designator (2008 - 2013) DDD : start day of year (001 - 366) HHMM : Hours and Minutes of AOS HH : (00 - 23) MM : (00 - 59) ext :> 3-character ASCII extension, WEA (to represent this is a weather file).  For example, a file name for a weather product from White Sands: WS1S_2009040_0824.WEA  Each WEA file is accompanied by a PDS label file that has a file name of the same form as the WEA file with an extension of LBL.  Laser Ranging Files (RANGE Directory) ------------------------------------- The Laser Ranging file contains the LOLA/SOC-processed one-way laser ranging fire time from data processing based on the telemetry that LOLA receives from the LRO Mission Operations Center (MOC) as part of the real-time and post- pass s/c and instrument housekeeping and measurement telemetry, and from station dependent fire time files retrieved from the Crustal Dynamics Data Information System (CDDIS) which contains files from the Next Generation Satellite Laser Ranging (NGSLR) and participating International Laser Ranging Service (ILRS) laser ranging sites [PEARLMANETAL2008]. The Laser Ranging files are ASCII files formatted as defined in [STDN7241990] and ILRS Consolidated Laser Ranging Data Format [RICKLEFSETAL2009].   Full Rate Files (RANGE/FULL_RATE Directory) ------------------------------------------- Laser Ranging full rate files contain LOLA SOC-processed one-way laser ranging fire time. Full rate data contains every outgoing ground station laser shot together with a corresponding LOLA receive signal whose pulse width is larger than 10 ns.   Normal Point Files (RANGE/NPT Directory) ---------------------------------------- Laser Ranging normal point files contain LOLA SOC-processed one-way laser ranging fire time. After outliers are removed from full-rate data, every 5 second interval with more than 5 full-rate points files will form one normal point per the procedure described in [SINCLAIR1997].   GEODYN Trajectory Files (SPK Directory) --------------------------------------- GEODYN SPK files are orbit reconstructions produced by the LOLA Precise Orbit Determination Team. They were used for geolocation of LOLA data. These files give spacecraft and planetary ephemerides and have the same binary format as SPK files generated by the LRO Flight Dynamics Team. Flight Dynamics SPKs can be found at naif.jpl.nasa.gov.  Unlike the majority of this data archive, SPKs are a higher level data product (level 5.) The raw data are level 1. We include SPKs here as an example of a higher level product that can be derived from the Radio Science Raw Data Archive.  File names have the form LRO_xxxx_yyyymm_model.BSP where xxxx is the mission phase including month, where applicable (CO : Commissioning; NO_01, NO_02, etc. stand for Nominal Mission, with the number corresponding to the month between stationkeeping maneuvers, yyyymm gives the date of generation (or version), and model corresponds to the gravity model used for the creation of this particular SPK file (e.g., GRGM900C_L600 stands for gravity model GRGM900C of degree and order 900 with a power law constraint applied for degree L>600 [LEMOINEETAL2014]).  Each trajectory file is accompanied by a PDS label with file name LRO_xxxx_yyyymmdd.LBL. Typical SPK files comprise one lunar month, with gaps during thrusting maneuvers.  Typical file sizes are approximately 30MB with the exception of Commissioning, which has a 72MB file size.  The reconstructed LRO trajectory contained in each SPK has been created by the LOLA Precision Orbit Determination (POD) Team in an effort to refine the trajectory of the spacecraft and to improve the Lunar Gravity field based on LRO tracking data [MAZARICOETAL2010].  The data were originally written out by the GEODYN orbit processor at five second intervals. They were then converted from the original true of date (IAU of date) coordinates to J2000, and then written in SPK files (type 8, discrete states, evenly spaced, Lagrange Interpolation).  The orbits were produced from an analysis of the Doppler and range data supplied by the LRO project. The primary tracking stations are the NASA/LRO White Sands S/Ka-band ground station and the Universal Space Network (USN) S-band sites. See the Appendix in CATALOG/INST.CAT for a list of LRO tracking stations. Altimetric crossovers constructed with LOLA data were also used in the POD to help improve the trajectory precision.  The various arcs were combined into SPKs spanning one mission phase (about a month). Trajectories from consecutive arcs were (linearly) tapered during overlap periods. Because the maneuvers (delta-H and station-keeping) were not modeled, the SPKs are discontinuous around those maneuvers.   Coordinate System : The SPICE (SPK) files use the J2000 reference frame internally, which is equivalent to the International Celestial Reference Frame. They do not depend on planetary ephemerides, but rather are relative to the Center of Mass (COM) of the Moon.  DE421 is used as the reference ephemeris of the Moon as specified by the Project. Where there is some dependence on coordinate frame in this dataset, it would be the DE421.  Software : No software is included with the archival data set. Spice toolkits can be downloaded from naif.jpl.nasa.gov.  Media/Format : This data set is stored online at the Planetary Data System (http://pds.nasa.gov/) and may be downloaded using a web browser or FTP software. A copy may be requested on physical media if downloading is not possible. The Planetary Data System maintains backup copies of this data set on various media.

Overview : Data in this archival data set have been collected to support radio science investigations, including derivation of the gravity field of the Moon. These are similar to data collected using other spacecraft and are believed to be generally of good quality.  Review : This archival data set was reviewed by the LRO Radio Science Team, a subunit of the Lunar Orbiter Laser Altimeter (LOLA) Team, prior to submission to the Planetary Data System (PDS). Data set design, documentation, and sample products have passed a PDS peer review.  Prior to creation of the final version of the archival data set, key elements of the archive were distributed for preliminary review. These included electronic versions of example PDS labels, example data files, CATALOG files, and Software Interface Specifications. These materials were distributed to PDS personnel, the experiment investigator, and others, as appropriate.   Data Coverage and Quality : Data set coverage is given by START_TIME and STOP_TIME except for the delivery of SPK files, which are derived products. These may lag delivery of tyhe raw data (TRK files). There is no significant variation in data quality with coverage.