HDPWS

ResourceID

spase://NASA/NumericalData/Voyager1/LECP/Particle/PT24H

Description

This data file contains 1 day averages of count rates for eleven differential energy proton/ion channels (30 keV - 20 MeV) and one integral channel (>70 MeV protons) from the Low Energy Charged Particle (LECP) instrument on Voyager 1. The interplanetary data listed are averaged over 24 hours, with the start time of the averging interval begining at the start of the day listed. For example, 77/300 is an average over hours 0-23 on day 300 of 1977. Times are given in SCET-UT. The count rates R are in counts per second. The statistical uncertainty for each channel is the inverse square root of the total number of counts during each 24 hour period times the average count rate R. Included in the data table are the passbands in KeV for protons, the logarithmic mean energy Em for the differential energy channels, the geometric factor "g" (cm**2-steradian), and the flux conversion factor "f". To get from count rate R to differential in energy flux "dj(E)/dE", multiply R by f,
i.e.,
dj(E)/dE=f*R.
Note that f is simply the inverse of the energy passband multiplied by
the geometric factor. Generally one uses a more elaborate algorithm to
calculate fluxes by determining the local slope of the energy spectrum within
each energy passband, usually by an iterative algorithm, and then evaluating
the flux corresponding to each channel using this slope. However, if the
slope of the energy spectrum is not to steep, the approximation dj(E)/dE=f*R
is very good if the flux is evaluated at the mean energy Em=Sqrt(EL*EH),
where EL and EH are the low and high energy ends of the passband. Since the
slopes of low energy ion spectra in the interplanetary medium are in the
range of -1 to -3, the approximation is very good.

Version:2.2.2

ResourceID

spase://NASA/NumericalData/Voyager1/LECP/Particle/PT24H

ResourceHeader

ResourceName

Voyager 1 LECP - Daily Average Interplanetary Data

ReleaseDate

2020-07-07 21:15:53Z

Description

This data file contains 1 day averages of count rates for eleven differential energy proton/ion channels (30 keV - 20 MeV) and one integral channel (>70 MeV protons) from the Low Energy Charged Particle (LECP) instrument on Voyager 1. The interplanetary data listed are averaged over 24 hours, with the start time of the averging interval begining at the start of the day listed. For example, 77/300 is an average over hours 0-23 on day 300 of 1977. Times are given in SCET-UT. The count rates R are in counts per second. The statistical uncertainty for each channel is the inverse square root of the total number of counts during each 24 hour period times the average count rate R. Included in the data table are the passbands in KeV for protons, the logarithmic mean energy Em for the differential energy channels, the geometric factor "g" (cm**2-steradian), and the flux conversion factor "f". To get from count rate R to differential in energy flux "dj(E)/dE", multiply R by f,
i.e.,
dj(E)/dE=f*R.
Note that f is simply the inverse of the energy passband multiplied by
the geometric factor. Generally one uses a more elaborate algorithm to
calculate fluxes by determining the local slope of the energy spectrum within
each energy passband, usually by an iterative algorithm, and then evaluating
the flux corresponding to each channel using this slope. However, if the
slope of the energy spectrum is not to steep, the approximation dj(E)/dE=f*R
is very good if the flux is evaluated at the mean energy Em=Sqrt(EL*EH),
where EL and EH are the low and high energy ends of the passband. Since the
slopes of low energy ion spectra in the interplanetary medium are in the
range of -1 to -3, the approximation is very good.

Acknowledgement

Use of these data in publications should be accompanied by acknowledgements of the NASA Space Physics Data Facility, the National Space Science Data Center and the responsible Principal Investigator defined in the experiment documentation provided here.

Contacts

Role | Person | StartDate | StopDate | Note | |
---|---|---|---|---|---|

1. | PrincipalInvestigator | spase://SMWG/Person/Stamatios.M.Krimigis | |||

2. | TechnicalContact | spase://SMWG/Person/Robert.B.Decker |

PriorIDs

spase://VSPO/NumericalData/Voyager1/LECP/Particle/PT24H

AccessInformation

RepositoryID

Availability

Online

AccessRights

Open

AccessURL

Name

FTPS from SPDF (not with most browsers)

URL

Description

In ASCII via FTP from SPDF

AccessURL

Name

HTTPS from SPDF

URL

Description

In ASCII via HTTP from SPDF

Format

Text

ProviderProcessingLevel

CALIBRATED

InstrumentIDs

MeasurementType

EnergeticParticles

TemporalDescription

TimeSpan

StartDate

1977-09-07 00:00:00

StopDate

1994-12-30 23:59:59

Cadence

PT24H

ObservedRegion

Heliosphere