urn:nasa:pds:a12sws_solar_wind_28s_1hr 1.0 1.23.0.0 Product_Bundle 2025 10.17189/ym2x-ye69 This data set contains daily tables of time ordered, 28-second-resolution plasma parameters, mainly of the solar wind, as observed on the Moon at the Apollo 12 ALSEP site by the Apollo 12 Solar Wind Spectrometer (SWS) from 19 November 1969 through 25 March 1976. This is the highest resolution data set available from the SWS instrument. This data set also contains tables of time ordered, hourly-averaged plasma parameters, mainly of the solar wind, as observed on the Moon at the Apollo 12 ALSEP site by the Apollo 12 Solar Wind Spectrometer from 19 November 1969 through 25 March 1976. David R. Williams National Space Science Data Center Producer Abigail Knight Washington University in St. Louis 2025-09-26 1.0 Initial bundle. 1969-11-19T18:42:13Z 1976-03-25T08:35:57Z Science Calibrated The 28-second SWS data tables are in fixed-width ASCII format. There is one table for each daily set of SWS measurements. Each daily table contains a sequence of plasma measurements made every 28.1 seconds. Each record in a table provides the time of a measurement, proton density, alpha-to-proton ratio, proton bulk speed, and angle of flow. Each record identifies the Faraday cup on the side of the instrument (one of six) that measured the most charge. The measured charge of this cup, the adjacent side cups, and the vertical (top) cup are included in each record as well as the most probable thermal speed, and various housekeeping and fit parameters relating to the reliability of the calculated plasma parameters. Note that a value of 99.0 in Column 14, the Percentage Error in Fitting Program, indicates the fit was bad and thus all computed plasma parameters in that row are invalid. These data tables were converted from the CDF format which was created from the original binary data set PSFP-00118 by the NSSDC as part of the Lunar Data Restoration project. The original tapes were written in BCD format on a UNIVAC 1108 computer. See Clay, et al. (1975), Goldstein, et al. (1973), Neugebauer, et al. (1972), and Snyder, et al. (1970) for more information about the SWS plasma data from Apollo 12. The hourly averaged SWS data tables are in fixed-width ASCII format. There is one table for each year the SWS recorded data. Each table provides four sets of computed hourly parameters using as input data: (1) all fine-time scale parameters (FTSP), (2) all FTSP computed from spectra with small root-mean-square (RMS) error on curve fitting and thermal speeds less than one-half the bulk velocity, (3) all FTSP computed from spectra that satisfy the requirements of criterion 2 as well as having only one flow angle that can be directly measured, and (4) all FTSP computed from spectra that satisfy the requirements of criterion 2 as well as having both flow angles directly measurable. Contained in each of the four sets of averages are the proton density, alpha-to-proton ratio, bulk speed, angle of flow, number of spectra, and RMS deviations of each average. These data tables were converted from the CDF format which was created from the original binary data set PSFP-00117 by the NSSDC as part of the Lunar Data Restoration project. The original tapes were written in BCD format on a UNIVAC 1108 computer. See Clay, et al. (1975), Goldstein, et al. (1973), Neugebauer, et al. (1972), and Snyder, et al. (1970) for more information about the SWS plasma data from Apollo 12. This data set description was provided by the NSSDC. Apollo 12 Mission urn:nasa:pds:context:investigation:mission.apollo_12 bundle_to_investigation The Apollo 12 Lunar Surface Experiments Package Host urn:nasa:pds:context:instrument_host:spacecraft.a12a is_instrument_host Apollo 12 Lunar Surface Experiments Package Solar Wind Spectrometer Instrument urn:nasa:pds:context:instrument:sws.a12a is_instrument Moon Satellite urn:nasa:pds:context:target:satellite.earth.moon bundle_to_target 10.1029/JA080i013p01751 Clay, D.R., B.E. Goldstein, M. Neugebauer and C.W. Snyder, Lunar surface solar wind observations at the Apollo 12 and Apollo 15 sites, Journal of Geophysical Research, 80, 1751-1760, 1975. Goldstein, B.E., D.R. Clay, C.W. Snyder and M. Neugebauer, ALSEP solar wind spectrometer plasma data as observed at the Apollo 12 and 15 landing sites, Jet Propulsion Laboratory, Contract NAS7-100, 1973. 10.1016/0032-0633(72)90184-5 Neugebauer, M., C.W. Snyder, D.R. Clay and B.E. Goldstein, Solar wind observations on the lunar surface with the Apollo-12 ALSEP, Planetary and Space Science, 20, 1577-1591, 1972. Snyder, C.W., D.R. Clay and M. Neugebauer, The solar-wind spectrometer experiment, Apollo 12 Preliminary Science Report, NASA SP-235, 75-81, published by NASA, Washington D.C., 1970. Archive readme.txt 2867 0 7-Bit ASCII Text Brief overview of this bundle. Carriage-Return Line-Feed urn:nasa:pds:a12sws_solar_wind_28s_1hr:data Primary bundle_has_data_collection urn:nasa:pds:a12sws_solar_wind_28s_1hr:document Primary bundle_has_document_collection