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Apollo 12 ALSEP Solar Wind Spectrometer 1-hour Data (PDS)


Availability: Archived at NSSDC, accessible from elsewhere

Time span: 0069-11-19 to 0076-03-25


This PDS data set 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 (SWS) from 19 November 1969 through 25 March 1976.

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.

This is PDS Data Set ID A12A-L-SWS-4-SOLAR-WIND-1HR-AVG-V1.0 held on Volume A12SW_0002. The data are available online at:

Alternate Names



  • Planetary Science: Fields and Particles

Additional Information



Questions and comments about this data collection can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. David R. WilliamsGeneral ContactNASA Goddard Space Flight
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