PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = "2021-08-20: Initial release; 2022-04-12: Updated per Liens 20230125 RChen/EN work around catalog ingest. Delete this line next time. " RECORD_TYPE = STREAM INSTRUMENT_HOST_NAME = "NEW HORIZONS" OBJECT = DATA_SET DATA_SET_ID = "NH-X-SWAP-5-DERIVED-SOLARWIND-V2.0" OBJECT = DATA_SET_INFORMATION ARCHIVE_STATUS = "LOCALLY ARCHIVED" START_TIME = 2008-10-10T21:07:14 STOP_TIME = 2020-01-27T06:56:02 DATA_SET_DESC = " Data Set Overview ================= The NH_SW_20081010_20200127 file of this data set provides the time information for a given pair of sweeps in the original CODMAC level 2 raw data file, the solar wind proton density, proton speed, proton temperature, proton dynamic pressure, and proton thermal pressure. It also has the spacecraft position in Heliographic Inertial (HGI), Heliocentric Aries Ecliptic (HAE-J2000), and Heliographic (HG). The NH_PICKUPIONS_2008_11_16 file of this data set provides the interstellar pickup ion density, temperature, and pressure that are described in detail in [MCCOMASETAL2017]. Version ======= This is VERSION 2.0 of this data set. The changes are (1) the addition of pickup ion product and (2) time expansion & all records updated of the solar wind product (due to updated SPICE information). Solar Wind Coverage =================== This data set specifically excludes SWAP data obtained while New Horizons was inside the Pluto system. The results provided here are for observations obtained when the solar wind beam was fully within the SWAP field of view. As explained by Heather Elliott (co-investigator): The solar wind is very radial the vast majority of the time. Since we do not have much angular information, we assume the solar wind is radial to perform our analysis. Inside the Pluto system, we have no way of knowing the direction of the ions or if we are measuring the full distribution function. We did a separate analysis for Pluto and have already published those results in [MCCOMASETAL2016], but those results to our best knowledge only reflect the portion of the distribution function that we measure and are not true density, speeds, and temperatures. Since we believe we do measure the full distribution function of the solar wind when the instrument was pointed such that the solar wind beam was well within the SWAP FOV, we refer to those results as true density, speed, and temperature. Solar Wind Processing ===================== The analysis of the count rate energy distributions (SWAP level 2 data archived at PDS) to produce solar wind parameters is described by [ELLIOTTETAL2016]. This paper includes a lengthy discussion of all the calibration information used to forward model the count rate distributions, the use of Poisson errors in the fit procedure, and shows comparisons to 1 AU and Voyager 2 solar wind observations. Interstellar Pickup Ions ======================== In brief, they are found by fitting the functional form of a filled shell distribution, i.e., the Vasyliunas & Siscoe distribution. This shell distribution is coupled with SWAP instrument responses in order to simulate the measured count rate-energy per charge distribution function. The fitting procedure minimizes the chi-square between the simulated and measured count rate-energy per charge distributions. After fitting the distribution to SWAP observations, the density, temperature, and pressure distributions are calculated by taking moments of the fitted distribution. As described in [MCCOMASETAL2017], this data set was culled for times when the solar wind speed varied over the ~24 hour period by >1% (~13% of the samples). Additionally, SWAP energy distribution that experienced a failing in the fit were manually removed (see [MCCOMASETAL2017], Section 5 for more details). This resulted in a removal of ~2% of the remaining data. In total, ~85% of the spectra remain. Reference Frame =============== Heliographic Inertial (HGI) --------------------------- This system is a Sun centered with the X-axis along the intersection line of the ecliptic (zero longitude occurs at the +X-axis) and solar equatorial planes. The Z-axis is perpendicular to the solar equator, and the Y-axis completes the right-handed system. This coordinate system is also referred to as the Heliocentric Inertial (HCI) system. Heliocentric Aries Ecliptic J2000 (HAE-J2000) --------------------------------------------- This coordinate system is a heliocentric system with the Z-axis normal to the ecliptic plane and the X-axis pointes toward the first point of Aries on the Vernal Equinox, and the Y-axis completes the right-handed system. This coordinate system is also referred to as the Solar Ecliptic (SE) coordinate system. The label 'J2000' refers to the time at which one defines the Vernal Equinox. In this case it is defined at the J2000 date, which is January 1, 2000 at noon. Heliographic (HG) ----------------- This system is similar to the Heliographic Inertial one except the zero longitude is fixed on the surface of the Sun and rotates with a period of 25.38 days. Specifically, the zero was defined as the longitude at the ascending node of the equator in the ecliptic plane on January 1, 1854 at 12 UT. This system is also known as the Carrington system and is an intrinsic system to Spacecraft Planet Instrument C-matric Events (SPICE) toolkit denoted as IAU_SUN where IAU stands for International Astronomical Union. Summary ------- The reference frames above are based on SPICE defined reference frames and central bodies. See below for a summary of their definitions in terms of SPICE. SPICE SPICE Reference Central Frame Body Description Name Name -------------------------------------------- ---- ---- Heliogr. Inertial (HGI) HCI Sun Heliocentr. Aries Eclip. J2000 (HAE-J2000) ECLIPJ2000 Sun Heliographic (HG) IAU_SUN Sun Epoch of Geometric Parameters ----------------------------- All geometric parameters provided in the data labels were computed at the epoch midway between the START_TIME and STOP_TIME label fields. " ABSTRACT_DESC = " This data set presents characteristics of the solar wind derived from data taken by the New Horizons Solar Wind Around Pluto (SWAP) instrument as well as pickup ions. This archive contains two data products. For the solar wind derived product each product compiles the CODMAC level 2 source data used, the solar wind proton density, proton speed, proton temerature, proton dynamic pressure, proton thermal pressure, and spacecraft position. For the pickup ion derived product the interstellar pickup ion density, temperature, and pressure is provided. For the solar wind, the data is derived from observations obtained during cruise, Pluto encounter (excluding the period inside the Pluto system), and afterwards. For the pickup ion data, the data set was culled for times when the solar wind speed varied over the ~24 hour period by >1% (~13% of the samples). This is VERSION 2.0 of this data set. The pickup ion data and additional solar wind data what is new to this version. " CITATION_DESC = " McComas, D., Elliott, H., Mukherjee, J., NEW HORIZONS SWAP DERIVED SOLAR WIND DATA V2.0, NH-X-SWAP-5-DERIVED-SOLARWIND-V2.0, NASA Planetary Data System, 2023." DATA_OBJECT_TYPE = "SPREADSHEET" DATA_SET_COLLECTION_MEMBER_FLG = "N" DATA_SET_NAME = " NEW HORIZONS SWAP SOLAR WIND DERIVED DATA V2.0 " DATA_SET_RELEASE_DATE = 2021-08-20 DATA_SET_TERSE_DESC = " This data set contains solar wind characteristics and pickup ions from the New Horizons Prime and Extended mission, derived from data from the New Horizons Solar Wind Around Pluto (SWAP) instrument. " DETAILED_CATALOG_FLAG = "N" PRODUCER_FULL_NAME = "HEATHER ELLIOTT" CONFIDENCE_LEVEL_NOTE = " The PickUp Ion file provides the interstellar pickup ion density, temperature, and pressure that are described in detail in [MCCOMASETAL2017]. The Solar Wind file provides proton density, speed, temperature, dynamic pressure and thermal pressure of the solar wind and the confidence in the final parameters is discussed in Elliott et al., 2016. [ELLIOTTETAL2016]. " END_OBJECT = DATA_SET_INFORMATION OBJECT = DATA_SET_MISSION MISSION_NAME = "NEW HORIZONS" END_OBJECT = DATA_SET_MISSION OBJECT = DATA_SET_MISSION MISSION_NAME = "NEW HORIZONS KUIPER BELT EXTENDED MISSION" END_OBJECT = DATA_SET_MISSION OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "ELLIOTTETAL2016" END_OBJECT = DATA_SET_REFERENCE_INFORMATION OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "MCCOMASETAL2017" END_OBJECT = DATA_SET_REFERENCE_INFORMATION OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "MCCOMASETAL2016" END_OBJECT = DATA_SET_REFERENCE_INFORMATION OBJECT = DATA_SET_TARGET TARGET_NAME = "SOLAR WIND" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_TARGET TARGET_NAME = "INTERSTELLAR PARTICLES" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_HOST INSTRUMENT_HOST_ID = "NH" INSTRUMENT_ID = "SWAP" END_OBJECT = DATA_SET_HOST END_OBJECT = DATA_SET END