ACE Electron Proton Alpha Monitor (EPAM) Data Products Provided by Fundamental Technologies, LLC
The ACE Science Center provides spin-averaged EPAM fluxes (intensities) at 5-minute, hourly, and daily cadences as standard ACE EPAM Level 2 Data Products.
A more comprehensive set of EPAM data products is provided by Fundamental Technologies, LLC (FunTech).
- ACE EPAM Home Page at FunTech - instrument documentation and publications
- ACE EPAM data documentation at FunTech
- Main ACE EPAM data download page at FunTech
Links to specific ACE EPAM data products available from FunTech. All data are in comma-separated-variable (CSV) ASCII files.
- Electron and ion count rates
Both sectored and spin-averaged, at 12-sec, 5-min, hourly and daily cadences.
- Electron and ion fluxes
Both sectored and spin-averaged, at 17-minute, hourly and daily cadences.
Energy spectra/fluxes of individual heavy ion species
PHA-derived, and background corrected. Hourly and Daily averages: He, C, O, Ne, Si, and Fe.
- Event by event pulse height analysis of DC(B) logic in calibrated form
- Electron and ion count rates
- Detailed List of ACE EPAM rates and fluxes available from FunTech, plus associated metadata, maintained by the Virtual Energetic Particle Observatory (VEPO).
The data references above are publication quality, subject to the same usage rules and warnings about observational characteristics of the instrument and spacecraft as regular EPAM Level 2 data.
Release notes for EPAM level 2 data - provided by the EPAM instrument team. All users of EPAM data should read these notes.
Notes on the comma-separated-variable (CSV) ASCII files provided by Fundamental Technologies, LLC
The data in the rates CSV files consist of count rates of solar ions and electrons, including both sectored and unsectored rates.
Explanation of EPAM Comma Separated Variable (CSV) Files. This document describes the format and content
of the EPAM 5-minute and 12-second CSV data files. Please read this document carefully before attempting to work
with these data. Note that the geometric factors and energy pass-bands in this document must be
used to convert the count-rate data into fluxes.
See also these docs, maintained by Fundamental Technologies, LLC.
Note on Computing Uncertainties in Rates and Flux dataIn the CSV files there are counting rates for each channel, each sector, so that the best way to estimate the counting statistical uncertainty is to evaluate the number of counts as 300*rate (c/sec) for the five minute averages. Then one may use the number of counts in whatever approximate for the statistic that suits the purpose. This assumes a 100% duty cycle, which isn't exactly true, but it's almost true. At least this works to ESTIMATE the uncertainty. If the channel in question happens to be presented in flux units it's still possible to get the uncertainties. In this case, one has to compute the rate first by multiplying the flux by the geometrical factor and passband.
The EPAM InstrumentThe Electron, Proton, and Alpha Monitor (EPAM) is composed of five telescope apertures of three different types. Two Low Energy Foil Spectrometers (LEFS) measure the flux and direction of electrons above 30 keV (geometry factor = 0.397 cm2*sr), two Low Energy Magnetic Spectrometers (LEMS) measure the flux and direction of ions greater than 50 keV (geometry factor = 0.48 cm2*sr), and the Composition Aperture (CA) measures the elemental composition of the ions (geometry factor = 0.24 cm2*sr). The telescopes use the spin of the spacecraft to sweep the full sky. Solid-state detectors are used to measure the energy and composition of the incoming particles. For more information about the EPAM instrument, visit the EPAM Home Page, at JHU/APL.
Last Updated: 19 Dec 2013