This section describes the product name convention and the product classification.
Product Name Convention
According to [AD13], Swarm product names consist of 10 digits, which are subdivided into two subfields as follows: TTTTTTTTTT = FFFFDDDDDD, where FFFF = File Category and DDDDDD = Semantic Descriptor.
For L2 products FFFF = FFFx, where FFF describes the product type (e.g. MCO  Magnetic Core Field) and for the single satelitte x = A, B or C for Swarm A, Swarm B, or Swarm C, respectively. If the product is derived from (available for) the satellite constellation (e.g. A and C) x = _.
The Semantic Descriptor DDDDDD = DDDy2z. DDD provides a description which is specific for each product, for example TMS for time series or SHA for spherical harmonics and y = _.
The last two digits describe the product level [AD13]. Therefore digit 9 is always 2, identifying the product as a L2 product. The last digit z indicates the origin or the purpose of the product. This applies especially when different chains lead to the same science product. This last digit z can be:
C
derived from Comprehensive Inversion
D
derived from dedicated chain
F
Fast Track product
E
Extended, only applied for extended lithospheric field maps (MLI_SHA_2E)
_
Only one chain has been identified to lead to this product type
a
Product derived from candidate chain a (only applied for mantle conductivity products  derived in the frequency domain)
b
Product derived from candidate chain b (only applied for mantle conductivity products  derived in the time domain)
Product Classification
L2 product Categories (Cat) have been defined in [AD12]. Each L2 product is attributed to one of these categories.
Cat1: Complex algorithms contributing to the generation of a L2 product of the various sources of the Earth's magnetic field, of thermospheric products, and for Precise Orbit determination. The generation of Cat1 products require interaction with experienced scientists. The products will be processed by SCARF, and will be distributed by ESA.
Cat2: Algorithms leading to a L2 product with minimum delay with respect to the generation of the corresponding Level 1b data. The generation of Cat2 products is designed to run automatically. The Cat2 products will be generated and distributed by ESA.
Fast Track products: The validation is performed by means of an internal quality check in the algorithms of each of these products, and the quality of the product is provided, e.g., by a quality flag. Fast Track products are released without a validation report. The Cat1 magnetic products, e.g. core field model and magnetospheric model, will be derived on Fast Track. All Cat2 products are Fast Track products. For all Fast Track products, the last letter of the product name is F (see Product Name Convention).
Validation Reports: For nonFast Track products a validation report is required. Validation reports are provided for each product chain (see L2 Product Overview Table). The intercomparison between products of two chains in one product family (e.g. MCO_SHA_2D and MCO_SHA_2C) will be released in one validation report (e.g MCO_VAL_2_). Validation report products exist for following product families (e.g.): core field models, lithospheric field models, ionospheric models, magnetosphere models, 1Dmantle conductivity (mantle conductivity model and Cresponse), 3Dmantle conductivity (mantle conductivity model and Cresponse maps), precise orbit determination, and thermospheric winds and density.
N/A (lithospheric field is considered constant over the analysed time range)
Update rate
One model every year
Latency
One month
Notes
⇒ L2 Cat1: MLI_SHA_2E
Product identifier
MLI_SHA_2E
Definition
Final map of the lithospheric field from the Revised Spherical Cap Harmonic analysis (RSCHA) Dedicated Lithospheric Inversion, expressed in terms of high degree Spherical Harmonics
N/A (lithospheric field is considered constant over the analysed time range)
Update rate
One model every year
Latency
One month
Notes
The product has the same format as the other lithospheric field models, but at a higher SH degree to be used for mapping purpose only. SH Gauss coefficients are here a mean to store the map, but the product itself is a map. The map should not be computed at altitudes lower than the minimum altitude of Swarm measurements
⇒ L2 Cat1: MLI_VAL_2C
Product identifier
MLI_VAL_2C
Definition
Validation report for lithospheric field model from CI chain
Input Data
MLI_SHAi2C, MLI_VALi2C, AUX_LIT_2_
Data volume
< 1 Mb per day
Data format
PDF
Output Data
PDF file
Update rate
First after 1 year, updated every year
Latency
1 month
Notes
⇒ L2 Cat1: MLI_VAL_2D
Product identifier
MLI_VAL_2
Definition
Validation report for lithospheric field model from dedicated
Input Data
MLI_SHAi2D, MLI_VALi2D, AUX_LIT_2_
Data volume
< 1 Mb per day
Data format
PDF
Output Data
PDF file
Update rate
One model every year
Latency
1 month
Notes
⇒ L2 Cat1: MLI_VAL_2_
Product identifier
MLI_VAL_2_
Definition
Comparison validation report for lithospheric field model
Cresponses (real and imaginary parts), their uncertainties and squared coherences on a set of periods
Output time span and resolution
N/A
Update rate
First version after 2 years, update every year
Latency
1 month
Notes
⇒ L2 Cat1: MI1_VAL_2_
Product identifier
MI1_VAL_2_
Definition
Validation report for 1D mantle conductivity
Input Data
MIN_1DMi2_, MI1_VALi2_
Data volume
< 1 Mb per day
Data format
PDF
Output Data
PDF file
Update rate
First version after 2 years, update every year
Latency
1 month
Notes
⇒ L2 Cat1: MC1_VAL_2_
Product identifier
MC1_VAL_2_
Definition
Validation report for 1D Cresponse
Input Data
MCR_1DMi2_, MC1_VALi2_
Data volume
< 1 Mb per day
Data format
PDF
Output Data
PDF file
Update rate
First version after 2 years, update every year
Latency
1 month
Notes
External Current Systems
⇒ L2 Cat1: MMA_SHA_2C
Product identifier
MMA_SHA_2C
Definition
Spherical harmonic representation of the large scale magnetospheric field and of its induced counterpart
Input data
MMA_SHAi2C, MMA_VAL_2_
Input time span
All available quiet time observations from the mission
Spatial representation
Spherical Harmonics of degree and order at least 1 for the external field and of degree and order at least 5 for its Earth induced counterpart
Time representation
Time series
Units
nT
Resolution
≤ 1 pT
Uncertainty
Refer to product quality report
Quality indicator
Statistics of data misfit provided in the validation report
Data volume
~2 MB/year
Data format
CDF
Various temporal resolutions may be employed for various external and internal coefficients, hence a number of CDF variable groups are used to store external (named "...qs_N") respectively internal (named "...gh_N") coefficients. Note: the temporal resolutions for the various groups of external and internal coefficients are usually not identical.
Name
Type
Dim
Unit
Contents
t_qs_1
CDF_EPOCH
1
ms
Time instants of external Gauss coefficients q (cosine) and s (sine)
qs_1
CDF_DOUBLE
1
nT
External Gauss coefficients q (cosine) and s (sine) in dipole frame corresponding to time instants t_qs_1
dqs_1
CDF_DOUBLE
1
nT
Formal error estimate for qs_1
nm_qs_1
CDF_INT2
1

First column: vector of spherical harmonic degrees of the coefficients qs_1.
Second column: vector of spherical harmonic orders. Nonnegative values denote coefficients q (cosine) while negative values denote coefficients s (sine)
t_qs_2
CDF_EPOCH
1
ms
Time instants of external Gauss coefficients q (cosine) and s (sine)
qs_2
CDF_DOUBLE
2
nT
External Gauss coefficients q (cosine) and s (sine) in dipole frame corresponding to time instants t_qs_2
dqs_2
CDF_DOUBLE
2
nT
Formal error estimate for qs_2
nm_qs_2
CDF_INT2
2

First column: vector of spherical harmonic degrees of the coefficients qs_2.
Second column: vector of spherical harmonic orders. Nonnegative values denote coefficients q (cosine) while negative values denote coefficients s (sine)
t_gh_1
CDF_EPOCH
1
ms
Time instants of induced Gauss coefficients g (cosine) and h (sine)
gh_1
CDF_DOUBLE
1
nT
Internal induced Gauss coefficients g (cosine) and h (sine) in dipole frame
dgh_1
CDF_DOUBLE
1
nT
Formal error estimate for gh_1
nm_gh_1
CDF_INT2
1

First column: vector of spherical harmonic degrees of the coefficients gh_1.
Second column: vector of spherical harmonic orders. Nonnegative values denote coefficients g (cosine) while negative values denote coefficients h (sine)
t_gh_2
CDF_EPOCH
1
ms
Time instants of induced Gauss coefficients g (cosine) and h (sine)
gh_2
CDF_DOUBLE
2
nT
Internal induced Gauss coefficients g (cosine) and h (sine) in dipole frame
dgh_2
CDF_DOUBLE
2
nT
Formal error estimate for gh_2
nm_gh_2
CDF_INT2
2

First column: vector of spherical harmonic degrees of the coefficients gh_2.
Second column: vector of spherical harmonic orders. Nonnegative values denote coefficients g (cosine) while negative values denote coefficients h (sine)
t_qual
CDF_EPOCH
1
ms
Time instants of quality information (rms, n_data, and q_flag).
rms
CDF_DOUBLE
2
nT
Rootmeansquare difference between models and input data (after processing to subtract nonmagnetospheric sources) in dipole frame, for the time instants indicated by t_qual
First column: RMS difference in radial direction. Second column: RMS difference in theta direction. Third column: RMS difference in phi direction.
n_data
CDF_UINT2
2

Number of data used at each timeinstant from each satellite.
First column: Number of data from SWARM A. Second column: Number of data from SWARM B. Third column: Number of data from SWARM C.
Output data
Time series of external and induced SH coefficients in dipole coordinate frame; rootmeansquare differences between (processed) input data and models; number of data from each satellite used for each model; quality flag
Output time span
Time span as input
Update rate
First after 1 year, updated every year
Latency
1.5 months
Notes
⇒ L2 Cat1: MMA_VAL_2C
Product identifier
MMA_VAL_2C
Definition
Validation report for magnetospheric field model from CI chain
Input data
MMA_SHAi2C, MMA_SHA_2F, MMA_VALi2C
Data volume
< 1 Mb per day
Data format
PDF
Output data
PDF file
Update rate
First after 1 year, updated every year
Latency
1 month
Notes
⇒ L2 Cat1: MMA_SHA_2F
Product identifier
MMA_SHA_2F
Definition
Spherical harmonic representation of the large scale magnetospheric field and its induced counterpart
Degree 1 spherical Harmonics for the external and internally induced fields
Time representation
Snapshot values 1.5 hours apart.
Units
See variable ‘Units' in ‘Data format', below.
Resolution
See variable ‘Type' in ‘Data format', below.
Uncertainty
Overall uncertainty will include contributions from uncertainties in the Input Data, which are not calculated here. Estimates of the uncertainty resulting from the modeling process after the Input Data has been processed can be obtained from the ‘rms' output variable.
Quality indicator
Rootmeansquare difference between model and (processed) input data; number of data used per model; quality flag.
Data volume
~5 MB/year
Data format
CDF
Name
Type
Dim
Unit
Contents
t_qs
CDF_EPOCH
1
ms
Time instants (CDFEPOCH) of external Gauss coefficients q (cosine) and s (sine)
qs_geo
CDF_DOUBLE
2
nT
External Gauss coefficients q (cosine) and s (sine) in Geographic frame
qs_sm
CDF_DOUBLE
2
nT
External Gauss coefficients q (cosine) and s (sine) in Solar Magnetic frame
nm_qs
CDF_INT2
2

First column: vector of spherical harmonic degrees of the coefficients qs_geo and qs_sm. Nonnegative values denote coefficients q (cosine) while negative values denote coefficients s (sine)
Second column: vector of spherical harmonic orders
t_gh
CDF_EPOCH
1
ms
Time instants (CDFEPOCH) of induced Gauss coefficients g (cosine) and h (sine)
gh_geo
CDF_DOUBLE
2
nT
Internal induced Gauss coefficients g (cosine) and h (sine) in Geographic frame
gh_sm
CDF_DOUBLE
2
nT
Internal induced Gauss coefficients g (cosine) and h (sine) in Solar Magnetic frame
nm_gh
CDF_INT2
2

First column: vector of spherical harmonic degrees of the coefficients gh_geo and gh_sm. Nonnegative values denote coefficients g (cosine) while negative values denote coefficients h (sine)
Second column: vector of spherical harmonic orders
t_qual
CDF_EPOCH
1
ms
Time instants (CDFEPOCH) of quality information (rms, n_data, and q_flag).
rms
CDF_DOUBLE
2
nT
Rootmeansquare difference between models and input data (after processing to subtract nonmagnetospheric sources) in geographic frame.
First column: RMS difference in radial direction. Second column: RMS difference in theta direction. Third column: RMS difference in phi direction.
n_data
CDF_UINT2
2

Number of data used at each timeinstant from each satellite.
First column: Number of data from SWARM A. Second column: Number of data from SWARM B. Third column: Number of data from SWARM C.
q_flag
CDF_UINT1
1

Product quality flag. Value of zero indicates good quality / no issues. The meaning of the individual bits are described below:
Bit
Set if
1
Input timeseries is shorter than 1year filter used to separate internal and external coefficients. This is unavoidable at the start of the mission.
2
Internal/external separation filter has at least one bad/missing datum. This is not necessarily serious (check n_data, above and bits 3 and 4, below).
3
total n_data for this model is < 90% of the expected maximum available.
4
Internal/external separation filter has at least one bad/missing datum amongst the most recent (five) where it is most sensitive.
Example: decimal ‘9' means bits ‘1' and ‘4' set.
Output data
Time series of external and induced SH coefficients in Solar Magnetic and Geographic coordinate frames; rootmeansquare differences between (processed) input data and models; number of data from each satellite used for each model; quality flag.
Output time span
1 day
Update rate
Daily
Latency
< 1 day
Notes
⇒ L2 Cat1: MIO_SHA_2C
Product identifier
MIO_SHA_2C
Definition
Spherical harmonic representation of the daily geomagnetic variations at mid and low latitudes (Sq and EEJ)
Input Data
MIO_SHAi2C, MIO_VAL_2_
Input time span
All available quiet time observations from the mission
Spatial representation
Spherical Harmonics up to degree 60 and order 12 in dipole coordinates
Time representation
Fourier Series, seasonal and daily periodicity
Units
nT
Resolution
1 pT
Uncertainty
Refer to product quality report
Quality indicator
Statistics of data misfit provided in the validation report
Relative_STEC_RMS (RMS deviation between code and carrier phases) and DCB_Error
Data volume
~4 MB / day / satellite
Data format
CDF
Variable Name
Description
Type
Unit
Timestamp
Time stamp in UTC
CDF_EPOCH
ms
Latitude
Geographic latitude
CDF_DOUBLE
degree
Longitude
Geographic longitude
CDF_DOUBLE
degree
Radius
Geographic radius
CDF_DOUBLE
m
GPS_Position
X,Y,Zcoordinates (WGS84) of the GPS satellite
CDF_DOUBLE
m
LEO_Position
X,Y,Zcoordinates (WGS84) of the LEO satellite
CDF_DOUBLE
m
PRN
GPS satellite PRN
CDF_UINT2
No Unit
L1
GPS L1 carrier phase observation
CDF_DOUBLE
m
L2
GPS L2 carrier phase observation
CDF_DOUBLE
m
P1
GPS P1 code phase observation
CDF_DOUBLE
m
P2
GPS P2 code phase observation
CDF_DOUBLE
m
S1
GPS signaltonoise ratio or raw signal strength on L1
CDF_DOUBLE
dBHz
S2
GPS signaltonoise ratio or raw signal strength on L2
CDF_DOUBLE
dBHz
Absolute_STEC
Absolute slant TEC
CDF_DOUBLE
TECU
Absolute_VTEC
Absolute vertical TEC
CDF_DOUBLE
TECU
ElevationAngle
Elevation angle
CDF_DOUBLE
degree
Relative_STEC
Relative slant TEC
CDF_DOUBLE
TECU
Relative_STEC_RMS
Root mean square error of relative slant TEC
CDF_DOUBLE
TECU
DCB
GPS receiver differential code bias
CDF_DOUBLE
TECU
DCB_Error
Error of the GPS receiver differential code bias
CDF_DOUBLE
TECU
Output data
CDF file with time series
Output time span
1 day
Latency
6 min
Update rate
1 per day
Notes
The cadence of the TECxTMS_2F data has changed from 10s (0.1 Hz) to 1s (1 Hz) at:
20140714 06:42:59 for Swarm A
20140714 06:06:46 for Swarm B
20140714 08:15:59 for Swarm C
It is recommended to use absolute VTEC data with corresponding elevation angles of the GPS rays of at least 50°.
⇒ L2 Cat2: FAC_TMS_2F
Product identifier
FAC_TMS_2F
Definition
Time series of fieldaligned and radial current densities along the orbit using the dualsatellite method. Fieldaligned current (FAC) density is derived by the multiplication of the radial current (IRC) density with the inclination angle of the geomagnetic field. The fieldaligned current density can only be calculated at latitudes, where the magnetic field is well inclined, i.e. I > 30°. Near the magnetic equator for magnetic inclination angles I < 30° FAC values are set to NaN. The radial current density can be provided along the whole orbit, except for latitudes θ>86° (near poles), where both FAC and IRC values are set to NaN.
Note that the magnetic field data used for the dualsatellite method is lowpass filtered with a 3dB cutoff period of 20 s (corresponding to a wavelength of 150 km). This step is indispensable because the lateral distance between Swarm A and Swarm C has to be taken into account.
Current density estimates along entire orbits at positions between SwA and SwC
Time representation
Time series of current density, Δt=1sec
Units
Current density: µA/m^{2}
Resolution
Current density: 1E6 µA/m^{2}
Uncertainty
50 nA/m^{2} for periods 10s to 90min on top of constant bias of <200nA/m^{2}, for latitudes below 80°, gradually degrading between 80° to 86°, no values beyond 86°
Quality indicator
Flags:
A table below presents the list of 10 individual and independent digits, characterizing the FACdual (FAC_TMS_2F) product quality. Digits from 1 to 8 report issues that may have been occurred at one or more of the measurement points used for the computation of a current density value. Digits 9 and 10 report whether the NaN values for the current density were used or not. Values N>0 mark the number of measurement points that were affected and value 0 marks not affected ones. For FACdual N can be equal to 1, 2, 3, or 4.
DigitNr.
Value
Meaning
1
0/N
A short (< 5 seconds) data gap occurred, which was interpolated linearly
2
0/N
A long (> 5 seconds) data gap occurred, which cannot be interpolated linearly, in the vicinity
3
0/N
No EST (external part of AUX_DST_2F) data were available, and a default value was used for the magnetospheric field model
4
0/N
No IST (external part of AUX_DST_2F) data were available, and a default value was used for the magnetospheric field model
5
0/N
No solar radio flux (AUX_F10_2F) data were available, and a default value was used for the magnetospheric field model
6
0/N
No interplanetary magnetic field (AUX_IMF_2F) data were available, and a default value was used for the magnetospheric field model
7
0/N
No Em (merging electric field) data were available, and a default value was used for the magnetospheric field model
8
0/N
No magnetospheric field coefficients (Aux_PMF_2F or Aux_PSM_2F or Aux_PGM_2F) were available, and magnetospheric field is set to 0
9
0/1
For FACdual, this digit is equal to 1 if latitude θ >86° (near geographic poles)
(IRC = NaN and FAC = NaN)
10
0/1
This digit is equal to 1 if inclination I < 30° (near magnetic equator)
(FAC = NaN)
Flags_B, Flags_F and Flags_q are handed through from Level 1b processing [AD5].
Data volume
5 MB per day
Data format
CDF
Variable Name
Data Type
Descriptions
Units
Timestamp
CDF_EPOCH
Time, UTC
milliseconds
Latitude
CDF_DOUBLE
Position in ITRF, Latitude
degrees
Longitude
CDF_DOUBLE
Position in ITRF, Longitude
degrees
Radius
CDF_DOUBLE
Position in ITRF, Radius
m
IRC
CDF_DOUBLE
Ionospheric radial current (IRC)
µA/m^{2}
IRC_Error
CDF_DOUBLE
uncertainty of IRC
µA/m^{2}
FAC
CDF_DOUBLE
Fieldaligned current (FAC)
µA/m^{2}
FAC_Error
CDF_DOUBLE
uncertainty of FAC
µA/m^{2}
Flags
CDF_UINT4
Flags characterizing the product quality (processing flags)

Flags_F
CDF_UINT4
Flags_F passed through from L1b and accumulated for quad points

Flags_B
CDF_UINT4
Flags_B passed through from L1b and accumulated for quad points

Flags_q
CDF_UINT4
Flags_q passed through from L1b and accumulated for quad points

Output data
CDF file with time series
Output time span
1day
Update rate
1 per day
Latency
10 min
Notes
⇒ L2 Cat2: FACxTMS_2F
Product identifier
FACxTMS_2F
Definition
Time series of fieldaligned and radial current densities along the orbit from single satellite measurements. Fieldaligned current (FAC) density is derived by the multiplication of the radial current (IRC) density with the inclination angle of the geomagnetic field. The fieldaligned current density can only be calculated at latitudes, where the magnetic field is well inclined, i.e. I > 30°. Near the magnetic equator for magnetic inclination angles I < 30° FAC values are set to NaN. The radial current density can be provided along the whole orbit. Scale size >7.5 km.
Current density estimates along entire orbits at positions of SwA, SwB, and SwC.
Time representation
Time series of current density, Δt=1sec
Units
Current density: µA/m^{2}
Resolution
Current density: 1E6 µA/m^{2}
Uncertainty
less than FAC_TMS_2F, 70 nA/m^{2} on top of constant bias of <200nA/m^{2}, for latitudes below 80°, gradually degrading between 80° to 86°, no values beyond 86°
Quality indicator
Flags:
A table below presents the list of 10 individual and independent digits, characterizing the FACsingle (FACxTMS_2F) product quality. Digits from 1 to 8 report issues that may have been occurred at one or more of the measurement points used for the computation of a current density value. Digits 9 and 10 report whether the NaN values for the current density were used or not. Values N>0 mark the number of measurement points that were affected and value 0 marks not affected ones. For FACsingle N can be equal to 1 or 2.
DigitNr.
Value
Meaning
1
0/N
A short (< 5 seconds) data gap occurred, which was interpolated linearly
2
0
For FACsingle, this digit is always zero because no filtering is done
3
0/N
No EST (external part of AUX_DST_2F) data were available, and a default value was used for the magnetospheric field model
4
0/N
No IST (external part of AUX_DST_2F) data were available, and a default value was used for the magnetospheric field model
5
0/N
No solar radio flux (AUX_F10_2F) data were available, and a default value was used for the magnetospheric field model
6
0/N
No interplanetary magnetic field (AUX_IMF_2F) data were available, and a default value was used for the magnetospheric field model
7
0/N
No Em (merging electric field) data were available, and a default value was used for the magnetospheric field model
8
0/N
No magnetospheric field coefficients (Aux_PMF_2F or Aux_PSM_2F or Aux_PGM_2F) were available, and magnetospheric field is set to 0
9
0
For FACsingle, this digit is always equal to 0
10
0/1
This digit is equal to 1 if inclination I < 30° (near magnetic equator)
(FAC = NaN)
Flags_B, Flags_F and Flags_q are handed through from Level 1b processing [AD5].
Data volume
5MB per day, per satellite
Data format
CDF
Variable Name
Data Type
Descriptions
Units
Timestamp
CDF_EPOCH
Time, UTC
milliseconds
Latitude
CDF_DOUBLE
Position in ITRF, Latitude
degrees
Longitude
CDF_DOUBLE
Position in ITRF, Longitude
degrees
Radius
CDF_DOUBLE
Position in ITRF, Radius
m
IRC
CDF_DOUBLE
Ionospheric radial current (IRC)
µA/m^{2}
IRC_Error
CDF_DOUBLE
uncertainty of IRC
µA/m^{2}
FAC
CDF_DOUBLE
Fieldaligned current (FAC)
µA/m^{2}
FAC_Error
CDF_DOUBLE
uncertainty of FAC
µA/m^{2}
Flags
CDF_UINT4
Flags characterizing the product quality (processing flags)

Flags_F
CDF_UINT4
Flags_F passed through from L1b and accumulated for quad points

Flags_B
CDF_UINT4
Flags_B passed through from L1b and accumulated for quad points

Flags_q
CDF_UINT4
Flags_q passed through from L1b and accumulated for quad points

Output data
CDF file with time series
Output time span
1day
Latency
10 min
Update rate
1 per day
Notes
⇒ L2: EEFxTMS_2F
Product identifier
EEFxTMS_2F
Definition
Dayside equatorial electric field
Input data
MAGx_LR_1B, MCO_SHA_2X
Input time span
Every dayside equator crossing ±20 minutes
Spatial representation
One longitude/latitude pair (on the magnetic equator ) for each output value
Time representation
Single values at time of dayside equator crossing
Units
V/m
Resolution
0.1 mV/m
Uncertainty
0.1 mV/m
Quality indicator
Relative error between modeled and observed current profile
Data volume
< 2 kB
Data format
CDF
Variable Name
Type
Description
Units
Timestamp
CDF_EPOCH
Timestamp of the EEF measurement (time of satellite crossing of magnetic equator)
Milliseconds
Longitude
CDF_DOUBLE
Geographic longitude of the Swarm satellite crossing of the magnetic equator
Degrees
Latitude
CDF_DOUBLE
Geographic latitude of the Swarm satellite crossing of the magnetic equator
Degrees
EEF
CDF_DOUBLE
Equatorial eastward electric field estimate
mV/m
EEJ
CDF_DOUBLE
Heightintegrated latitude profile of equatorial eastward current estimate (lenght 81)
mA/m
RelErr
CDF_DOUBLE
Relative error between modelled and observed equatorial electrojet current
N/A
Flags
CDF_UINT2
Value describing the quality of the EEF estimate. Also contains identification information for Swarm satellite (A,B,C)
N/A
Output data
CDF file with time series
Output time span
Continuous for entire mission. One value for each dayside equator crossing (90 minute sampling for daynight local time orbits, 45 minutes for dawndusk orbits)
Update rate
One output file per day
Latency
30 hours
Notes
The EEJ vector has length 81 and corresponds to QD latitudes ranging from 20° to +20° in steps of 0.5°. So for example, the corresponding QD latitude vector could be constructed using the following MATLAB syntax: qdvec = [20:0.5:20].
Jin Y, Spicher A, Xiong C, Clausen L, Kervalishvili G, Stolle C, Miloch W (2019), "Ionospheric plasma irregularities characterized by the Swarm satellites: statistics at high latitudes", Journal of Geophysical Research: Space Physics, Vol. 124, pp. 1262–128, DOI: 10.1029/2018JA026063
Definition
Time series of characteristics of the plasma density and plasma irregularities along the orbit from single satellite measurements. Time series of local plasma conditions, including background density and total electron content. Data related to geomagnetic regions in the ionosphere. Indication of severity of plasma irregularities for groundbased users provided
Input data
EFI_LP_1B, TECxTMS_2F, AOBxFAC_2F, IBIxTMS_2F, PCP – Polar Cap Products
Input time span
3 days
Spatial representation
Data provided along entire orbits at positions of SwA, SwB, and SwC
Time representation
1 second time series (the electron density data are downsampled to 1 second resolution; the timestamp of the electron density and TEC data are rounded to the nearest integer UTC seconds)
Units
See data format table
Resolution
Temporal data resolution of 1 second, density variations estimated at 0.5 second resolution
Uncertainty
N/A
Quality indicator
Quality flags are handed through from Level 1b and Level 2 processing which is used as input data
Data volume
ca.10 MB per day, per satellite
Data format
CDF
Output data
CDF file with time series
Variable Name
Data Type
Descriptions
Units
Timestamp
CDF_EPOCH
Time, UTC
milliseconds
Latitude
CDF_DOUBLE
Position in ITRF – Latitude
deg
Longitude
CDF_DOUBLE
Position in ITRF – Longitude
deg
Radius
CDF_DOUBLE
Position in ITRF – Radius
m
Ne
CDF_DOUBLE
Plasma density; directly copied from the Langmuir probe files
cm^3
Background Ne
CDF_DOUBLE
Background density; calculated from Ne using a percentile filter
cm^3
Foreground Ne
CDF_DOUBLE
Foreground density; calculated from Ne using a percentile filter
cm^3
Te
CDF_DOUBLE
Electron temperature; directly copied from the Langmuir probe files
K
PCP_flag
CDF_INT4
The polar cap patch flag

Grad_Ne@100km
CDF_DOUBLE
The electron density gradient in a running window calculated via linear regression over 27 data points for the 2 Hz electron density data
cm^3/m
Grad_Ne@50km
CDF_DOUBLE
The electron density gradient in a running window calculated via linear regression over 13 data points for the 2 Hz electron density data
cm^3/m
Grad_Ne@20km
CDF_DOUBLE
The electron density gradient in a running window calculated via linear regression over 5 data points for the 2 Hz electron density data
cm^3/m
Grad_Ne@PCP_edge
CDF_DOUBLE
The linear electron density gradient calculated over the edges of a patch; nonzero only at the edges of polar cap patches
cm^3/m
ROD
CDF_DOUBLE
Rate Of change of Density
cm^3/s
RODI10s
CDF_DOUBLE
Rate Of change of Density Index (RODI) is the standard deviation of ROD over 10 seconds
cm^3/s
RODI20s
CDF_DOUBLE
Rate Of Density Index (RODI) is the standard deviation of ROD over 20 seconds
cm^3/s
delta_Ne10s
CDF_DOUBLE
Derived by subtracting Ne by its median filtered value in 10 seconds; indicates the electron density fluctuations smaller than 75 km
cm^3
delta_Ne20s
CDF_DOUBLE
Derived by subtracting Ne by its median filtered value in 20 seconds; indicates the electron density fluctuations smaller than 150 km
cm^3
delta_Ne40s
CDF_DOUBLE
Derived by subtracting Ne by its median filtered value in 40 seconds; indicates the electron density fluctuations smaller than 300 km
cm^3
num_GPS_satellites
CDF_INT4
Total number of tracked GPS satellites above 20 degrees

mVTEC
CDF_DOUBLE
Median of VTEC from all available GPS satellites above 30 degrees
TECU
mROT
CDF_DOUBLE
Median of Rate Of TEC (ROT) from all available GPS satellites above 30 degrees
TECU/s
mROTI10s
CDF_DOUBLE
Median of Rate Of TEC Index (ROTI) from all available GPS satellites above 30 degrees. The ROTI of each satellite is the standard deviation of ROT over 10 seconds
TECU/s
mROTI20s
CDF_DOUBLE
Median of Rate Of TEC Index (ROTI) from all available GPS satellites above 30 degrees. The ROTI of each satellite is the standard deviation of ROT over 20 seconds
TECU/s
IBI_flag
CDF_INT4
Plasma Bubble Index, copied from the level2 Ionospheric Bubble Index product, IBIxTMS_2F

Ionopshere_region_ flag
CDF_INT4
0: equator, 1: midlatitudes; 2: auroral oval; 3: polar cap

IPIR_index
CDF_INT4
03 low, 45 medium, and > 6 high level of fluctuations in the ionospheric plasma density

Ne_quality_flag
CDF_INT4
Quality flag for the Ne data and the derived data from Ne, e.g., background density, foreground density etc. It is a mixture of the LP and TII QFlags. It is calculated as LP_QFLAG*1000 + TII_QFLAG

TEC_STD
CDF_DOUBLE
Standard deviation of VTEC from GPS satellites
TECU
Output time span
1 day
Update rate
1 per day
Latency
10 min
Notes
The meanings of the PCP_flag are as follows: 0 if the plasma density measurement occurred outside a polar cap patch. 1 if the plasma density measurement occurred at one of the edges of a polar cap patch (no plasma velocity measurements are available). 2 if the plasma density measurement occurred at the leading edge of a polar cap patch. 3 if the plasma density measurement occurred at the trailing edge of a polar cap patch. 4 if the plasma density measurement occurred inside a polar cap patch proper. When no ion drift data is available, the leading and trailing edges cannot be distinguished. In this case the polar cap patch flag is set to 4 throughout the patch proper and to 1 throughout both edges
Swarm magnetic field (MAGL) measurements, CHAMP magnetic field measurements, model predictions of core, lithospheric and largescale magnetospheric (including Earthinduced) contributions, taken by the CHAOS geomagnetic field model, OMNI solar wind measurements, F10.7 index
Input time span
Entire Swarm mission + entire CHAMP mission
Spatial representation
Spherical harmonic expansion in QD/modified apex coordinates, with degree up to 45/65 for poloidal/toroidal magnetic field parts. Spherical harmonic order (in MLT) up to 3
Time representation
Time dependence contained in parametrization in terms of external parameters: 20 min average solar wind speed and interplanetary magnetic field, dipole tilt angle, and F10.7 index
Units
Magnetic field in nT, horizontal sheet current density in mA/m, vertical current density in µA/m^{2}
Central 24 hr of input time span will be selected for SP3 product
Quality report will be provided as separate Level 2 product
⇒ L2 Cat1: SP3xVAL_2_
Product identifier
SP3xVAL_2_
Definition
Validation report for precise orbit solutions SP3xCOM_2_ and SP3xKIN_2_
Input Data
SP3xCOM_2_, SP3xKIN_2_, ILRS Swarm tracking data, Diagnostic and statistical output from orbit determination process
Input Time Span
30 hr
Data volume
< 20 Mb per satellite per day
Data format
PDF
Output Data
PDF file
Output time span
24 hr
Update rate
1 day
Latency
21 per day
Notes
30 hr time input time span includes overlaps between consecutive orbit solutions
⇒ L2 Cat1: ACCxPOD_2_
Product identifier
ACCxPOD_2_
Definition
Time series of nongravitational and aerodynamic accelerations obtained by POD
Input data
GPSx_RO_1B, STRxATT_1B, SC_xDYN_1B, External data from CODE
Input time span
30 hr (daily batches with overlap)
Spatial representation
N/A
Time representation
UTC (seconds – s), time step = 30 sec
Units
m/s^{2 }
Resolution
64 bit double precision floating point number format
Uncertainty
10^{7} m/s^{2 }variance for alongtrack and crosstrack directions
Quality indicator
Validation report DNSxVAL_2_
Data volume
< 10 Kb per satellite per day
Data format
CDF
Field name
Type
Dimension
Unit
Contents
time
CDF_EPOCH
1
ms
Observation time
acc_pod
CDF_REAL8
3
m/s^{2}
Estimated nongravitational accelerations (X,Y,Z)
acc_pod_aero
CDF_REAL8
3
m/s^{2}
Estimated aerodynamic accelerations (X,Y,Z)
validity_flag_tot
CDF_INT8
1

Flag for variable "acc_pod"
0 = nominal data
1 = anomalous data
validity_flag
CDF_INT8
1

Flag for variable "acc_pod_aero"
0 = nominal data
1 = anomalous data
Output data
CDF file with time series of accelerations
Output time span
24 hr
Update rate
1 month
Latency
21 days
Notes
The total nongravitational acceleration (variable "acc_pod") is used for calibrating the accelerometer data (in product "ACCxCAL_2"), whereas the aerodynamic acceleration (variable "acc_pod_aero") is used for the calculation of thermosphere density (in product "DNSxPOD_2").
Accelerometry
⇒ L2 Cat1: ACCxCAL_2_
Product identifier
ACCxCAL_2_
Definition
Time series of corrected and calibrated acceleration, including all corrections and calibration parameters
Threedimensional time series along satellite orbit
Time representation
UTC
Units
m/s^{2} for accelerations, unitless for scale factors and flags
Resolution
64 bit double precision floating point number format
Uncertainty
0.01 scale factor for flight direction, 10^{7} m/s^{2} for alongtrack bias
Quality indicator
Validation report ACCxVAL_2_
Global attribute "DAILY_QUALITY_INDEX" of Type CDF_REAL, which ranges from 1.0 (good data quality) to 5.0 (bad data quality)
Data volume
15 MB per day
Data format
CDF
Field name
Type
Dimension
Unit
Contents
time
CDF_EPOCH
1
ms
Epoch of observation (UTC)
a_cal
CDF_REAL8
3
m/s^{2}
Calibrated linear acceleration (X,Y,Z)
a_stp
CDF_REAL8
3
m/s^{2}
Step correction for linear accelerations
a_tmp
CDF_REAL8
3
m/s^{2}
Temperature correction for linear accelerations
a_gg
CDF_REAL8
3
m/s^{2}
Gravity gradient correction for linear accelerations
a_aa
CDF_REAL8
3
m/s^{2}
Angular acceleration correction for linear accelerations
a_ca
CDF_REAL8
3
m/s^{2}
Centrifugal acceleration correction for linear accelerations
s
CDF_REAL8
3
N/A
Scale factor (time series) for linear accelerations
b
CDF_REAL8
3
m/s^{2}
Bias for linear accelerations
spike_index
CDF_REAL8
3
m/s^{2}
Vector indicating per axis the size of artificial spikes in linear accelerations
flag_cor
CDF_UINT4
1
N/A
Flag indicating which corrections are applied
flag_val
CDF_UINT4
1
N/A
Flag indicating if data is valid
flag_thr
CDF_UINT4
1
N/A
Flag indicating if thruster activations
Output data
CDF file with corrected and calibrated accelerations from the accelerometer, all corrections and calibration parameters, and flags; sampling rate is 1 Hz (accelerations are at original measurement epochs)
Output time span
1 day
Update rate
3 months
Latency
1 month
Notes
All accelerations are provided in the CRF (xdirection is roughly alongtrack, ydirection is roughly crosstrack, zdirection is roughly nadir)
Calibration was performed against nongravitational accelerations from POD that are contained in product ACCxPOD_2_
⇒ L2 Cat1: ACCxVAL_2_
Product identifier
ACCxVAL_2_
Definition
Validation report for measured, modeled and POD accelerations ACCxCAL_2_, ACCxDISi2_
Thermospheric density at the satellite location along with auxiliary parameters (altitude, latitude, longitude and local solar time). Derived from nongravitational accelerations based on precise orbit determination data only (ACCxPOD_2_)
Input data
MODx_SC_1B, STRxATT_1B, SC_xDYN_1B, ACCxPOD_2_
Input time span
24 hr
Spatial representation
Timeseries along satellite track, altitude (m), latitude (deg), longitude (deg) and local solar time (hours) available based on MODx_SC_1B
Time representation
UUTC (seconds – s), nominally with 30 s time step, as well as orbital averages
Units
kg/m^{3} for density
Resolution
64 bit double precision floating point number format
Uncertainty
30% of variance from models for neutral density
Quality indicator
Validation report DNSxVAL_2_
Data volume
< 160 Kbyte per satellite per day
Data format
CDF
Field name
Type
Dimension
Unit
Contents
time
CDF_EPOCH
1
ms
Time of observation
density
CDF_REAL8
1
kg/m^{3}
Density derived from GPS accelerations
density_orbitmean
CDF_REAL8
1
kg/m^{3}
Orbitaverage of density derived from GPS accelerations
validity_flag
CDF_INT8
1

0 = nominal data
1 = anomalous data
altitude
CDF_REAL8
1
m
Altitude
latitude
CDF_REAL8
1
deg
Geodetic latitude
longitude
CDF_REAL8
1
deg
Geodetic longitude
local_solar_time
CDF_REAL8
1
hours
Local solar time
Output data
CDF file with time series
Output time span
24 hr
Update rate
1 month
Latency
21 days
Notes
The density data is derived from the ACCxPOD aerodynamic acceleration component along the spacecraft Xaxis.
The density_orbitmean field contains the mean density, taken over one orbital period, for each time step. The orbital period in seconds is provided as metadata in the CDF file.
At high altitude and low solar activity, the errors inherent in the radiation pressure model and acceleration determination using GPS data can become significant compared to the magnitude of the acceleration signal. This can result in large density errors and even negative densities. Users are advised to use the orbit mean densities in those conditions.
⇒ L2 Cat1: DNSxACC_2_
Product identifier
DNSxACC_2_
Definition
Thermospheric density at the satellite location derived from ACCxCAL_2
Input data
STRxATT_1B, SC_xDYN_1B, ACCxCAL_1, MODx_SC_1B, external data from IERS, F10.7 and Kp indices from external source
Input time span
24 hr
Spatial representation
Timeseries along satellite track, altitude (m), latitude (deg), longitude (deg) and local solar time (hours) available based on MODX_SC_1B
Time representation
UTC (seconds – s), nominally with 10 s time step
Units
kg/m^{3} for density
Resolution
64 bit double precision floating point number format
Uncertainty
30% of variance from models for neutral density
Quality indicator
Global attribute "DAILY_QUALITY_INDEX" copied from ACCxCAL_2
Validation report TDAxVAL_2_
Monthly average of Earth's gravity field, i.e. with an implicit epoch located at the middle of the calendar month
Units
See output data
Resolution
12 significant digits in scientific notation
Uncertainty
Typically 12 mm geoid height or 12 cm Equivalent Water Height discrepancy w.r.t. GRACE over land areas during low solar activity periods, considering Gaussian smoothing with 750km spherical cap radius
Quality indicator
RMS over ocean areas that are 6 degrees away from coast lines, after removing longterm trend, annual and semiannual variations estimated from monthly unweighted averages of numerous GRACE models (AIUB02, CSR05, GRGS03, ITSG14, GFZ05a, JPL05 and TNJ01)
Degree, order, cosine coefficient, sine coefficient (columns 5 and 6 set to zero)
Output time span
1 calendar month
Update rate
Quarterly
Latency
5 months
Notes
 Stokes coefficients available up to degree 40
 No smoothing applied
 GRACE comparison indicates that there is little useful geophysical signal above roughly degree 12, i.e. it suggest the signaltonoise ratio drops below 1 at those degrees and above