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Data Access
FTPBrowser
FTPS from SPDF (not with most browsers)
HTTPS from SPDF
IMP 8 Cosmic Ray Nuclear Composition (CRNC) 15-min PHA and coincidence mode counts
ResourceID
spase://NASA/NumericalData/IMP8/CRNC/PT15M
Description
This 15-min-resolution data set consists of 5 count rates from the Low Energy Telescope,
8 count rates for the main telescope (MT), 4 counts of pulse height analyzed events in each of 4 MT
coincidence modes, and 27 box counts corresponding to specific species and energy ranges associated
with 3 of the MT coincidence modes. Actually the 13 referenced "count rates" are given as paired counts
and accumulation times. Associated documentation suggests algorithms for computation of count rates and
fluxes from the MT data given, for electrons in 3 energy bands (0.7-2.0, 2.0-12, 12-50 MeV), protons in 9 bands
(11.24-20.00 MeV to 74.50-94.78 MeV), helium nuclei in 10 bands (10.90-12.89 MeV per n to 84.32-94.81 MeV per n),
and CNO nuclei in 1 band (25 - 250 Mev per n). There are no azimuthally sectored data in this data set.
The data are accessible via ftp and, with higher functionality, via FTPBrowser.
Metadata Rights
CC0-1.0:
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions. The actual data/software may be subject to a different license.
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Details
Version:2.7.1
NumericalData
ResourceID
spase://NASA/NumericalData/IMP8/CRNC/PT15M
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
IMP 8 Cosmic Ray Nuclear Composition (CRNC) 15-min PHA and coincidence mode counts
ReleaseDate
2026-06-26 13:17:55Z
RevisionHistory
RevisionEvent
ReleaseDate
2021-03-11 18:39:11Z
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2025-12-04 13:29:34Z
Note
Added MetadataRightsList and RightsList(s). Added ResourceType and NamingAuthority. Updated to 2.7.1. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. ZCB
RevisionEvent
ReleaseDate
2026-06-26 13:17:55Z
Note
Add 'Z' to TemporalDescription:TimeSpan:StartDate, TemporalDescription:TimeSpan:StopDate. ZCB
Description
This 15-min-resolution data set consists of 5 count rates from the Low Energy Telescope,
8 count rates for the main telescope (MT), 4 counts of pulse height analyzed events in each of 4 MT
coincidence modes, and 27 box counts corresponding to specific species and energy ranges associated
with 3 of the MT coincidence modes. Actually the 13 referenced "count rates" are given as paired counts
and accumulation times. Associated documentation suggests algorithms for computation of count rates and
fluxes from the MT data given, for electrons in 3 energy bands (0.7-2.0, 2.0-12, 12-50 MeV), protons in 9 bands
(11.24-20.00 MeV to 74.50-94.78 MeV), helium nuclei in 10 bands (10.90-12.89 MeV per n to 84.32-94.81 MeV per n),
and CNO nuclei in 1 band (25 - 250 Mev per n). There are no azimuthally sectored data in this data set.
The data are accessible via ftp and, with higher functionality, via FTPBrowser.
Acknowledgement
C. Lopate, UNH, and the late J. Simpson, U. Chi
Contacts
Role
Person
StartDate
StopDate
Note
1.
GeneralContact
spase://SMWG/Person/Clifford.Lopate
InformationURL
Name
Voldesc file at SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/imp/imp8/particles_uchi/15min_asci/voldesc.sfd
Description
Detailed documentation file about experiment and data
PriorIDs
spase://VEPO/NumericalData/IMP8/UChi/PT15M
spase://VEPO/NumericalData/IMP8/CRNC/PT15M
spase://VSPO/NumericalData/IMP8/CRNC/PT15M
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF
Availability
Online
AccessRights
Open
RightsList
Rights
SchemeURI
https://spdx.org/licenses/
RightsIdentifierScheme
SPDX
RightsIdentifier
CC0-1.0
RightsURI
https://spdx.org/licenses/CC0-1.0.html
RightsName
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
AccessURL
Name
FTPBrowser
URL
https://omniweb.gsfc.nasa.gov/ftpbrowser/chicago.html
Description
Interface to plot or list parameter subsets
AccessURL
Name
FTPS from SPDF (not with most browsers)
URL
ftps://spdf.gsfc.nasa.gov/pub/data/imp/imp8/particles_uchi/15min_asci/
Description
download files by ftp
AccessURL
Name
HTTPS from SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/imp/imp8/particles_uchi/15min_asci/
Description
In CDF via HTTP from SPDF
Format
Text
DataExtent
Quantity
320
Units
MB
Acknowledgement
C. Lopate, UNH, the late J. Simpson, U. Chicago, and the NSSDC and SPDF at GSFC
ProcessingLevel
Uncalibrated
InstrumentIDs
spase://SMWG/Instrument/IMP8/CRNC
MeasurementType
EnergeticParticles
TemporalDescription
TimeSpan
StartDate
1973-10-30 00:00:00Z
StopDate
2000-09-30 00:00:00Z
Cadence
PT15M
ObservedRegion
Heliosphere.NearEarth
Caveats
Data must be processed to obtain count rates and fluxes. Note that records with no data have spacecraft ID = 0 in first word.
Parameter #1
Name
Coincidence mode counts
Description
A set of 13 counts of events corresponding various telescope coincidence modes and discriminator levels
Cadence
PT15M
Structure
Size
13
Description
A set of 13 counts of events corresponding various telescope coincidence modes and discriminator levels. Counts are due to a mix of protons and alpha particles identified below plus 0.7-50 MeV electrons.
Particle
ParticleType
Proton
ParticleType
AlphaParticle
ParticleQuantity
Counts
EnergyRange
Low
0.54
High
94.78
Units
MeV per n
Parameter #2
Name
Count accumulation durations
Description
A set of 13 accumulation durations (in seconds) corresponding to the 13 coincidence mode counts described above
Cadence
PT15M
Units
sec
Structure
Size
13
Description
A set of 13 accumulation durations (in seconds) corresponding to the 13 coincidence mode counts described above
Support
SupportQuantity
Other
Parameter #3
Name
Counts of events pulse height analyzed
Description
A set of 4 counts of events pulse height analyzed in various coincidence modes for this interval for the CPI main telescope
Cadence
PT15M
Structure
Size
4
Description
A set of 4 counts of events pulse height analyzed in various coincidence modes for this interval. Counts are due to a mix of protons and alpha particles identified below plus 0.7-50 MeV electrons.
Particle
ParticleType
Proton
ParticleType
AlphaParticle
ParticleQuantity
Counts
EnergyRange
Low
11.24
High
94.78
Units
MeV per n
Parameter #4
Name
Box counts for specific species
Description
A set of 27 counts in E-dE/dx boxes corresponding to known species and energy ranges. In particular, there are 9 proton counts with energy ranges between 11.24-12.62 MeV and 74.50-94.78 MeV plus 2 proton counts aggregated over subsets of the 9, 10 alpha particle counts with energy ranges between 10.90-12.89 MeV/n and 84.32-94.81 MeV/n plus 2 alpha particle counts aggregated over subsets of the 10, 3 electron boxes at 0.7-2.0 MeV, 2.0-12 MeV, and 12-50 MeV, and one CNO box at ~25-250 MeV/n
Caveats
Data and companion documentation (algorithms, geometric factors, etc.) enable calculation of count rates and fluxes
Cadence
PT15M
Structure
Size
27
Description
A set of 27 box counts as described above
Particle
ParticleType
Proton
ParticleType
AlphaParticle
ParticleQuantity
Counts
EnergyRange
Low
11.24
High
94.78
Units
MeV per n