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PSP - SWEAP SPC - fits

ResourceID
spase://CNES/NumericalData/CDPP-AMDA/PSP/SPC/psp-spc-fit

Description
This data product contains derived measurements of ion properties in the solar wind, including density, temperature, velocity vector. The velocity, temperature, and density of the solar wind proton population are estimated by fitting each spectrum to a single Maxwellian or a set of Maxwellian ion populations. * p1 fit to the “primary” proton peak. This is the peak or largest amplitude observed in a given l2i spectrum. A locus of measurements is selected that includes the absolute maximum and at least the 1/e folding, if possible, on either side for this fit. * a fit to the “primary” alpha particle (He++) peak, if resolved. For l3i measurements, this is “guessed” by searching for a secondary peak in each l2i spectrum in the neighborhood of twice the p1 peak energy. * 3 if an additional high signal-to-noise feature is present in the l2i spectrum, typically due to a proton beam or shoulder but also potentially due to a cold minor ion population, a fit is attempted to the p1-subtracted residuals on this neighborhood. The POP3_MTOQ variable is used to indicate the species. * p_tot if p1 and 3 are successfully fit, and the 3 population is determined to be protons, this signifies the total proton parameters (np =total proton density, vp = center of mass velocity, wp = effective thermal velocity, accounting for both populations and their relative drift).

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Details

Version:2.4.1

NumericalData

ResourceID
spase://CNES/NumericalData/CDPP-AMDA/PSP/SPC/psp-spc-fit
ResourceHeader
ResourceName
PSP - SWEAP SPC - fits
AlternateName
SWEAP Level 3 fits
ReleaseDate
2025-10-12 20:24:13Z
Description
This data product contains derived measurements of ion properties in the solar wind, including density, temperature, velocity vector. The velocity, temperature, and density of the solar wind proton population are estimated by fitting each spectrum to a single Maxwellian or a set of Maxwellian ion populations. * p1 fit to the “primary” proton peak. This is the peak or largest amplitude observed in a given l2i spectrum. A locus of measurements is selected that includes the absolute maximum and at least the 1/e folding, if possible, on either side for this fit. * a fit to the “primary” alpha particle (He++) peak, if resolved. For l3i measurements, this is “guessed” by searching for a secondary peak in each l2i spectrum in the neighborhood of twice the p1 peak energy. * 3 if an additional high signal-to-noise feature is present in the l2i spectrum, typically due to a proton beam or shoulder but also potentially due to a cold minor ion population, a fit is attempted to the p1-subtracted residuals on this neighborhood. The POP3_MTOQ variable is used to indicate the species. * p_tot if p1 and 3 are successfully fit, and the 3 population is determined to be protons, this signifies the total proton parameters (np =total proton density, vp = center of mass velocity, wp = effective thermal velocity, accounting for both populations and their relative drift).
Acknowledgement
Please acknowledge the NASA Parker Solar Probe Mission and SWEAP team led by Justin Kasper for use of data.
Contacts
Role Person StartDate StopDate Note
1. PrincipalInvestigator spase://SMWG/Person/Justin.C.Kasper
2. CoInvestigator spase://SMWG/Person/Anthony.W.Case

InformationURL
Name
User Guide
URL
https://spdf.sci.gsfc.nasa.gov/pub/data/psp/sweap/sweap_data_user_guide.pdf
Description
User Guide for Parker Solar Probe SWEAP-SPC Investigation Data Products
AccessInformation
RepositoryID
spase://SMWG/Repository/CDPP/AMDA
Availability
Online
AccessRights
Open
AccessURL
Name
CDPP/AMDA HAPI Server
URL
https://amda.irap.omp.eu/service/hapi
Style
HAPI
ProductKey
psp-spc-fit
Description
Web Service to this product using the HAPI interface.
Format
CSV
Acknowledgement
Thank you for acknowledging the use of AMDA in publications with wording like "Data analysis was performed with the AMDA science analysis system provided by the Centre de Données de la Physique des Plasmas (CDPP) supported by CNRS, CNES, Observatoire de Paris and Université Paul Sabatier, Toulouse". See the Rules of the road at https://amda.cdpp.eu/help/policy.html . Please acknowledge the Data Providers.
AccessInformation
RepositoryID
spase://SMWG/Repository/CDPP/AMDA
Availability
Online
AccessRights
Open
AccessURL
Name
CDPP/AMDA Web application
URL
https://amda.cdpp.eu
Description
Access to Data via CDPP/AMDA Web application.
Format
CSV
Format
VOTable
Format
CDF
Format
PNG
Acknowledgement
Thank you for acknowledging the use of AMDA in publications with wording like "Data analysis was performed with the AMDA science analysis system provided by the Centre de Données de la Physique des Plasmas (CDPP) supported by CNRS, CNES, Observatoire de Paris and Université Paul Sabatier, Toulouse". See the Rules of the road at https://amda.cdpp.eu/help/policy.html . Please acknowledge the Data Providers.
ProviderName
SPDF
ProviderResourceName
psp/sweap/spc/l3/l3i/
InstrumentIDs
spase://CNES/Instrument/CDPP-AMDA/PSP/SPC
MeasurementType
Spectrum
TemporalDescription
TimeSpan
StartDate
2018-10-30 23:59:59Z
StopDate
2025-05-30 03:29:14Z
CadenceMin
PT0.2S
CadenceMax
PT30S
ObservedRegion
Heliosphere.Inner
ObservedRegion
Sun.Corona
Parameter #1
Name
np1
ParameterKey
psp_spc_np1
Description
Number density, fitted to the “primary” proton peak
Units
cm-3
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
NumberDensity
Parameter #2
Name
np1_uncertainty
ParameterKey
psp_spc_dnp1
Description
Estimated uncertainty on the number density, fitted to the “primary” proton peak
Units
cm-3
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
NumberDensity
Parameter #3
Name
wp1
ParameterKey
psp_spc_wp1
Description
Thermal velocity = sqrt(2kT/m), fitted to the “primary” proton peak
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #4
Name
wp1_uncertainty
ParameterKey
psp_spc_dwp1
Description
Estimated uncertainty on the thermal velocity, fitted to the “primary” proton peak
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #5
Name
vp1_rtn
ParameterKey
psp_spc_vp1
Description
Velocity vector, estimated from the radial thermal velocity fit p1 and flow angle
Units
km/s
RenderingHints
DisplayType
TimeSeries
Structure
Size
3
Element
Name
vp1r
Qualifier
Component.I
Index
1
ParameterKey
psp_spc_vp1(0)
Element
Name
vp1t
Qualifier
Component.J
Index
2
ParameterKey
psp_spc_vp1(1)
Element
Name
vp1n
Qualifier
Component.K
Index
3
ParameterKey
psp_spc_vp1(2)
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #6
Name
vp1_uncertainty
ParameterKey
psp_spc_dvp1
Description
Velocity vector component upper uncertainties
Units
km/s
RenderingHints
DisplayType
TimeSeries
Structure
Size
3
Element
Name
dvp1r
Qualifier
Component.I
Index
1
ParameterKey
psp_spc_dvp1(0)
Element
Name
dvp1t
Qualifier
Component.J
Index
2
ParameterKey
psp_spc_dvp1(1)
Element
Name
dvp1n
Qualifier
Component.K
Index
3
ParameterKey
psp_spc_dvp1(2)
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #7
Name
|vp1|
ParameterKey
psp_spc_vp1_nrm
Description
Velociy vector magnitude
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #8
Name
na
ParameterKey
psp_spc_na
Description
Number density, fitted to the “primary” alpha particle (He++) peak, if resolved
Units
cm-3
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
NumberDensity
Parameter #9
Name
na_uncertainty
ParameterKey
psp_spc_dna
Description
Estimated uncertainty on the number density, fitted to the “primary” alpha particle (He++) peak, if resolved
Units
cm-3
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
NumberDensity
Parameter #10
Name
wa
ParameterKey
psp_spc_wa
Description
Thermal velocity = sqrt(2kT/m), fitted to the “primary” alpha particle (He++) peak, if resolved
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #11
Name
wa_uncertainty
ParameterKey
psp_spc_dwa
Description
Estimated uncertainty on the thermal velocity, fitted to the “primary” alpha particle (He++) peak, if resolved
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #12
Name
va_rtn
ParameterKey
psp_spc_va
Description
Velocity vector, estimated from the radial thermal velocity fit and flow angle
Units
km/s
RenderingHints
DisplayType
TimeSeries
Structure
Size
3
Element
Name
var
Qualifier
Component.I
Index
1
ParameterKey
psp_spc_va(0)
Element
Name
vat
Qualifier
Component.J
Index
2
ParameterKey
psp_spc_va(1)
Element
Name
van
Qualifier
Component.K
Index
3
ParameterKey
psp_spc_va(2)
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #13
Name
va_uncertainty
ParameterKey
psp_spc_dva
Description
Velocity vector component uncertainties
Units
km/s
RenderingHints
DisplayType
TimeSeries
Structure
Size
3
Element
Name
dvar
Qualifier
Component.I
Index
1
ParameterKey
psp_spc_dva(0)
Element
Name
dvat
Qualifier
Component.J
Index
2
ParameterKey
psp_spc_dva(1)
Element
Name
dvan
Qualifier
Component.K
Index
3
ParameterKey
psp_spc_dva(2)
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #14
Name
|va|
ParameterKey
psp_spc_va_nrm
Description
Velociy vector magnitude
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #15
Name
n3
ParameterKey
psp_spc_n3
Description
Number density, fitted to the p1 substracted residuals
Units
cm-3
RenderingHints
DisplayType
TimeSeries
Particle
ParticleQuantity
NumberDensity
Parameter #16
Name
n3_uncertainty
ParameterKey
psp_spc_dn3
Description
Estimated uncertainty on the number density, fitted to the p1 substracted residuals
Units
cm-3
RenderingHints
DisplayType
TimeSeries
Particle
ParticleQuantity
NumberDensity
Parameter #17
Name
w3
ParameterKey
psp_spc_w3
Description
Thermal velocity = sqrt(2kT/m), fitted to the p1 substracted residuals
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleQuantity
Velocity
Parameter #18
Name
w3_uncertainty
ParameterKey
psp_spc_dw3
Description
Estimated uncertainty on the thermal velocity, fitted to the p1 substracted residuals
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleQuantity
Velocity
Parameter #19
Name
v3_rtn
ParameterKey
psp_spc_v3
Description
Velocity vector, estimated from the radial thermal velocity fit and flow angle
Units
km/s
RenderingHints
DisplayType
TimeSeries
Structure
Size
3
Element
Name
v3r
Qualifier
Component.I
Index
1
ParameterKey
psp_spc_v3(0)
Element
Name
v3t
Qualifier
Component.J
Index
2
ParameterKey
psp_spc_v3(1)
Element
Name
v3n
Qualifier
Component.K
Index
3
ParameterKey
psp_spc_v3(2)
Particle
ParticleQuantity
Velocity
Parameter #20
Name
v3_uncertainty
ParameterKey
psp_spc_dv3
Description
Velocity vector component uncertainties
Units
km/s
RenderingHints
DisplayType
TimeSeries
Structure
Size
3
Element
Name
dv3r
Qualifier
Component.I
Index
1
ParameterKey
psp_spc_dv3(0)
Element
Name
dv3t
Qualifier
Component.J
Index
2
ParameterKey
psp_spc_dv3(1)
Element
Name
dv3n
Qualifier
Component.K
Index
3
ParameterKey
psp_spc_dv3(2)
Particle
ParticleQuantity
Velocity
Parameter #21
Name
|v3|
ParameterKey
psp_spc_v3_nrm
Description
Velociy vector magnitude
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleQuantity
Velocity
Parameter #22
Name
np_tot
ParameterKey
psp_spc_np_tot
Description
If p1 and 3 are successfully fitted, total proton density
Units
cm-3
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
NumberDensity
Parameter #23
Name
np_tot_uncertainty
ParameterKey
psp_spc_dnp_tot
Description
Estimated uncertainty on the number density
Units
cm-3
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
NumberDensity
Parameter #24
Name
wp_tot
ParameterKey
psp_spc_wp_tot
Description
If p1 and 3 are successfully fitted, effective thermal velocity
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #25
Name
wp_tot_uncertainty
ParameterKey
psp_spc_dwp_tot
Description
Estimated uncertainty on the thermal velocity
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #26
Name
vp_tot_rtn
ParameterKey
psp_spc_vp_tot
Description
If p1 and 3 are successfully fitted, center of mass velocity vector
Units
km/s
RenderingHints
DisplayType
TimeSeries
Structure
Size
3
Element
Name
vp_totr
Qualifier
Component.I
Index
1
ParameterKey
psp_spc_vp_tot(0)
Element
Name
vp_tott
Qualifier
Component.J
Index
2
ParameterKey
psp_spc_vp_tot(1)
Element
Name
vp_totn
Qualifier
Component.K
Index
3
ParameterKey
psp_spc_vp_tot(2)
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #27
Name
vp_tot_uncertainty
ParameterKey
psp_spc_dvp_tot
Description
Velocity vector component uncertainties
Units
km/s
RenderingHints
DisplayType
TimeSeries
Structure
Size
3
Element
Name
dvp_totr
Qualifier
Component.I
Index
1
ParameterKey
psp_spc_dvp_tot(0)
Element
Name
dvp_tott
Qualifier
Component.J
Index
2
ParameterKey
psp_spc_dvp_tot(1)
Element
Name
dvp_totn
Qualifier
Component.K
Index
3
ParameterKey
psp_spc_dvp_tot(2)
Particle
ParticleType
Proton
ParticleQuantity
Velocity
Parameter #28
Name
|vp_tot|
ParameterKey
psp_spc_vp_tot_nrm
Description
Velociy vector magnitude
Units
km/s
RenderingHints
DisplayType
TimeSeries
Particle
ParticleType
Proton
ParticleQuantity
Velocity
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Last Updated: 2025-10-12