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Data Access
FTPS from SPDF (not with most browsers)
HTTPS from SPDF
CDAWeb
WebService:
CDAWeb Programmatic Data Access
HAPI: CDAWeb HAPI Server
Alouette 2 Topside Electron Density Profiles Manually Scaled at CRC
var authors='Jackson, John E.';
document.write(authors);
(2026).
Alouette 2 Topside Electron Density Profiles Manually Scaled at CRC.
[Data set].
Space Physics Data Facility.
https://doi.org/10.48322/y5gh-s748. Accessed on document.write(currentDateStr);.
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ResourceID
spase://NASA/NumericalData/Alouette2/SFS/PT32S
Description
This data set, provided by the Communications Research Centre (CRC) in Ottawa, Canada, consists of electron density profiles derived from Alouette 2 Sweep-Frequency Sounder for the ionosphere above the F2 maximum (topside ionosphere). The data set was originally provided on an EBCDIC magnetic tape written on an IBM 360 computer. The electron density profiles were computed from digital values of frequency and virtual height, scaled from ionograms. The data are ordered chronologically and include about 11,000 profiles. Telemetry stations are not identified, but satellite location, Greenwich mean time of observation, solar zenith angle at the satellite, dip latitude at the satellite, total electron content down to the lowest height of topside signal reflection (normally near 300 km), and other relevant information is noted with each profile. The format gives sequences of numbers for each point scaled from the ionogram. These sequences include electron density at the successive points, and the coefficients a2, b3, b4, b5, etc. from which geometric heights can be calculated, using formulas 40 and 41 in J. E. Jackson, "The reduction of topside ionograms to electron-density profiles," Proceedings of the IEEE., p. 960, June 1969. These formulas can also be used to calculate interpolated density-height values. A CRC interpolation program available at NSSDC can be used with this data set. The ionograms were selected for their scientific interest and comprise only a very small portion of reductions possible from the available ionograms. Data obtained prior to March 9, 1970, are also available on microfiche from NSSDC.
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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Version:2.7.1
NumericalData
ResourceID
spase://NASA/NumericalData/Alouette2/SFS/PT32S
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
Alouette 2 Topside Electron Density Profiles Manually Scaled at CRC
DOI
https://doi.org/10.48322/y5gh-s748
ReleaseDate
2026-04-30 16:34:01Z
RevisionHistory
RevisionEvent
ReleaseDate
2021-04-27 15:38:11Z
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2025-12-04 13:28:27Z
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
2026-04-10 09:58:44Z
Note
Added new Contact(s). ZCB
RevisionEvent
ReleaseDate
2026-04-10 10:03:42Z
Note
Added PublicationInfo. ZCB
RevisionEvent
ReleaseDate
2026-04-30 16:34:01Z
Note
Added DOI. tlk
Description
This data set, provided by the Communications Research Centre (CRC) in Ottawa, Canada, consists of electron density profiles derived from Alouette 2 Sweep-Frequency Sounder for the ionosphere above the F2 maximum (topside ionosphere). The data set was originally provided on an EBCDIC magnetic tape written on an IBM 360 computer. The electron density profiles were computed from digital values of frequency and virtual height, scaled from ionograms. The data are ordered chronologically and include about 11,000 profiles. Telemetry stations are not identified, but satellite location, Greenwich mean time of observation, solar zenith angle at the satellite, dip latitude at the satellite, total electron content down to the lowest height of topside signal reflection (normally near 300 km), and other relevant information is noted with each profile. The format gives sequences of numbers for each point scaled from the ionogram. These sequences include electron density at the successive points, and the coefficients a2, b3, b4, b5, etc. from which geometric heights can be calculated, using formulas 40 and 41 in J. E. Jackson, "The reduction of topside ionograms to electron-density profiles," Proceedings of the IEEE., p. 960, June 1969. These formulas can also be used to calculate interpolated density-height values. A CRC interpolation program available at NSSDC can be used with this data set. The ionograms were selected for their scientific interest and comprise only a very small portion of reductions possible from the available ionograms. Data obtained prior to March 9, 1970, are also available on microfiche from NSSDC.
PublicationInfo
Authors
Jackson, John E.
PublicationDate
2026-04-10 10:03:42Z
PublishedBy
Space Physics Data Facility
Contacts
Role
Person
StartDate
StopDate
Note
1.
PrincipalInvestigator
spase://SMWG/Person/John.E.Jackson
2.
GeneralContact
spase://SMWG/Person/Dieter.K.Bilitza
PriorIDs
spase://VSPO/NumericalData/P_ALOUETTE2_HDR_NEPROF
spase://VSPO/NumericalData/Alouette2/SFS/PT32S
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
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
FTPS from SPDF (not with most browsers)
URL
ftps://spdf.gsfc.nasa.gov/pub/data/alouette/topside_sounder/crc_ne_profile_cdf/alouette2/
AccessURL
Name
HTTPS from SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/alouette/topside_sounder/crc_ne_profile_cdf/alouette2/
Description
In CDF via HTTP from CDAWeb
AccessURL
Name
CDAWeb
URL
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=ALOUETTE2_NEPROF_TOPS&index=sp_phys
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CDAWeb Programmatic Data Access
URL
https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/ALOUETTE2_NEPROF_TOPS/clientLibraryExample/
Style
WebService
ProductKey
ALOUETTE2_NEPROF_TOPS
Description
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Format
Binary
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
CDAWeb HAPI Server
URL
https://cdaweb.gsfc.nasa.gov/hapi
Style
HAPI
ProductKey
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Description
Web Service to this product using the HAPI interface.
Format
CSV
ProviderProcessingLevel
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InstrumentIDs
spase://SMWG/Instrument/Alouette2/SFS
MeasurementType
ThermalPlasma
TemporalDescription
TimeSpan
StartDate
1965-12-15 09:40:15
StopDate
1972-07-10 22:37:22
Cadence
PT32S
ObservedRegion
Earth.NearSurface.Ionosphere