Specification of Level 2 Products
This section describes the product name convention and the product classification.
Product Name Convention
According to [AD-13], Swarm product names consist of 10 digits, which are subdivided into two sub-fields 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 [AD-13]. 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) |
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Product Classification
L2 product Categories (Cat) have been defined in [AD-12]. Each L2 product is attributed to one of these categories.
Cat-1: 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 Cat-1 products require interaction with experienced scientists. The products will be processed by SCARF, and will be distributed by ESA.
Cat-2: Algorithms leading to a L2 product with minimum delay with respect to the generation of the corresponding Level 1b data. The generation of Cat-2 products is designed to run automatically. The Cat-2 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 Cat-1 magnetic products, e.g. core field model and magnetospheric model, will be derived on Fast Track. All Cat-2 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 non-Fast Track products a validation report is required. Validation reports are provided for each product chain (see L2 Product Overview Table). The inter-comparison 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, 1D-mantle conductivity (mantle conductivity model and C-response), 3D-mantle conductivity (mantle conductivity model and C-response maps), precise orbit determination, and thermospheric winds and density.
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Level 2 Product Overview
Complete information about the Swarm Level 2 products can be found in the following document: "Product specification for L2 Products and Auxiliary Products".
More information about Science Objectives can be found on the Mission Overview web page.
Science Objective |
Product Name |
Description |
Format |
Extension |
Core Field |
MCO_SHA_2C |
Cat-1: Spherical harmonic model of the main (core) field and its temporal variation |
ASCII listing |
.shc |
MCO_SHA_2D |
Cat-1: Spherical harmonic model of the main (core) field and its temporal variation |
ASCII listing |
.shc |
MCO_VAL_2C |
Cat-1: Validation report on core magnetic field |
PDF |
.pdf |
MCO_VAL_2D |
Cat-1: Validation report on core magnetic field |
PDF |
.pdf |
MCO_VAL_2_ |
Cat-1: Validation report on core magnetic field |
PDF |
.pdf |
MCO_SHA_2F |
Cat-1: Spherical harmonic model of the main (core) field and its temporal variation |
ASCII listing |
.shc |
MCO_SHA_2X |
Cat-1: Spherical harmonic model of the main (core) field and its temporal variation |
ASCII listing |
.shc |
Lithospheric Field |
MLI_SHA_2C |
Cat-1: Spherical harmonic model of the lithospheric field |
ASCII listing |
.shc |
MLI_SHA_2D |
Cat-1: Spherical harmonic model of the lithospheric field |
ASCII listing |
.shc |
MLI_VAL_2C |
Cat-1: Validation report on lithospheric field |
PDF |
.pdf |
MLI_VAL_2D |
Cat-1: Validation report on lithospheric field |
PDF |
.pdf |
MLI_VAL_2_ |
Cat-1: Validation report on lithospheric field |
PDF |
.pdf |
Mantle Conductivity |
MIN_1DM_2_ |
Cat-1: 1D model of mantle conductivity |
ASCII listing |
.txt |
MCR_1DM_2_ |
Cat-1: 1D C-response maps |
ASCII listing |
.txt |
MI1_VAL_2_ |
Cat-1: Validation report on 1D mantle conductivity |
PDF |
.pdf |
MC1_VAL_2_ |
Cat-1: Validation report on 1D C-response |
PDF |
.pdf |
External Current Systems |
MMA_SHA_2C |
Cat-1: Spherical harmonic model of the large-scale magnetospheric field and its Earth-induced counterpart |
CDF |
.cdf |
MMA_VAL_2C |
Cat-1: Validation report magnetospheric magnetic model |
PDF |
.pdf |
MMA_SHA_2F |
Cat-1: Spherical harmonic model of the large-scale magnetospheric field and its Earth-induced counterpart |
CDF |
.cdf |
MIO_SHA_2C |
Cat-1: Spherical harmonic model of the daily geomagnetic variation at middle latitudes (Sq) and low latitudes (EEJ) |
ASCII listing |
.txt |
MIO_SHA_2D |
Cat-1: Spherical harmonic model of the daily geomagnetic variation at middle latitudes (Sq) and low latitudes (EEJ) |
ASCII listing |
.txt |
MIO_VAL_2C |
Cat-1: Validation report on ionospheric magnetic model |
PDF |
.pdf |
MIO_VAL_2D |
Cat-1: Validation report on ionospheric magnetic model |
PDF |
.pdf |
MIO_VAL_2_ |
Cat-1: Validation report on ionospheric magnetic model |
PDF |
.pdf |
IBIxTMS_2F |
Cat-2: Ionospheric bubble index |
CDF |
.cdf |
TECxTMS_2F |
Cat-2: Time series of the ionospheric total electron content |
CDF |
.cdf |
FAC_TMS_2F |
Cat-2: Time series of field-aligned currents
(FAC-dual) |
CDF |
.cdf |
FACxTMS_2F |
Cat-2: Time series of field-aligned currents
(FAC-single) |
CDF |
.cdf |
EEFxTMS_2F |
Cat-2: Equatorial Electric Field |
CDF |
.cdf |
IPDxIRR_2F |
Time series of characteristics of the plasma density and plasma irregularities along the orbit from single satellite measurements |
CDF |
.cdf |
Precise Orbit Determination |
SP3xCOM_2_ |
Cat-1: time series of position and velocity of the center of mass of each satellite (reduced-dynamic POD) |
ASCII listing |
.sp3 |
SP3xKIN_2_ |
Cat-1: time series of position of the center of mass of each satellite (kinematic POD) |
ASCII listing |
.sp3 |
SP3xVAL_2_ |
Cat-1: Validation report for SP3xCOM_2_ |
PDF |
.pdf |
ACCxPOD_2_ |
Cat-1: Time series of non-gravitational accelerations estimated by POD |
CDF |
.cdf |
Accelerometry |
ACCxCAL_2_ |
Cat-1: Corrected and calibrated accelerometer observations |
CDF |
.cdf |
ACCxVAL_2_ |
Cat-1: Validation report for ACCxCAL_2_ |
PDF |
.pdf |
Magnetic Forcing of the Upper Atmosphere |
ACCx_AE_2_ |
Cat-1: Time series of calibrated and pre-processed accelerometer observations and of aerodynamic accelerations |
CDF |
.cdf |
DNSxPOD_2_ |
Cat-1: time series of neutral thermospheric density from precise orbit determination data only |
CDF |
.cdf |
DNSxACC_2_ |
Cat-1: time series of neutral thermospheric density |
CDF |
.cdf |
Gravity Field |
EGF_SHA_2_ |
Cat-1: Monthly gravity field of the Earth |
ASCII listing |
.gcf |
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Level 2 Products
Core Field
? L2 Cat-1: MCO_SHA_2C
Product identifier |
MCO_SHA_2C |
Definition |
Spherical harmonic model of the main (core) field and its temporal variation |
Input Data |
MCO_SHAi2C, MCO_VAL_2_ |
Input Time Span |
All available quiet time observations from the mission |
Spatial representation |
Spherical Harmonics up to degree 18 |
Time representation |
Snapshot models, based on order 5 splines with 6 months knots spacing |
Units |
nT |
Resolution |
1 pT |
Uncertainty |
Refer to quality report |
Quality indicator |
Statistics of data misfit provided in validation report |
Data volume |
~10 kB |
Data format |
ASCII table (SHC) [AD-15] |
Output Data |
Gauss coefficients |
Output time span |
As input time span but with some extrapolations |
Update rate |
First after 1 year, updated every year |
Latency |
1.5 months |
Notes |
|
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? L2 Cat-1: MCO_SHA_2D
Product identifier |
MCO_SHA_2D |
Definition |
Spherical harmonic model of the main (core) field and its temporal variation |
Input Data |
MCO_SHAi2D, MCO_VAL_2_ |
Input Time Span |
Nominal minimum of 1 year up to the full Swarm data span |
Spatial representation |
Spherical Harmonics up to degree 18 |
Time representation |
Snapshot models (corresponding to 1/2 year knot separation and order 6 splines) |
Units |
nT |
Resolution |
1 pT |
Uncertainty |
Refer to quality report |
Quality indicator |
Statistics of data misfit, power spectra etc. provided in validation report |
Data volume |
~10 kB |
Data format |
ASCII table (SHC) [AD-15] |
Output Data |
Gauss coefficients |
Output time span |
Time span same as for input |
Update rate |
1 per year |
Latency |
6 weeks |
Notes |
The model accuracy strongly depends on the LT offset between the A and C satellite pair and the satellite B |
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? L2 Cat-1: MCO_VAL_2C
Product identifier |
MCO_VAL_2C |
Definition |
Validation report for core field model from CI chain |
Input Data |
MCO_SHAiC, MCO_VALi2C, AUX_OBS_2_, AUX_IGR_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 |
|
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? L2 Cat-1: MCO_VAL_2D
Product identifier |
MCO_VAL_2D |
Definition |
Validation report for core field model from dedicated chain |
Input Data |
MCO_SHAi2D, MCO_VALi2D, AUX_OBS_2_, AUX_IGR_2_ |
Data volume |
< 1 Mb per day |
Data format |
PDF |
Output Data |
PDF file |
Update rate |
1 per year |
Latency |
1 month |
Notes |
|
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? L2 Cat-1: MCO_VAL_2_
Product identifier |
MCO_VAL_2_ |
Definition |
Comparative validation report for core field models |
Input Data |
MCO_SHA_2C, MCO_SHA_2D, MCO_VAL_2C, MCO_VAL_2D, AUX_OBS_2_, AUX_IGR_2_ |
Data volume |
< 1 Mb per day |
Data format |
PDF |
Output Data |
PDF file |
Update rate |
Each time both, MCO_SHA_2C and MCO_SHA_2D have been released |
Latency |
1 month |
Notes |
|
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? L2 Cat-1: MCO_SHA_2F
Product identifier |
MCO_SHA_2F |
Definition |
Spherical harmonic model of the main (core) field and its temporal variation |
Input Data |
MAGx_LR_1B, AUX_IGR_2_, AUX_COR_2_, AUX_LIT_2_, AUX_DST_2_, AUX_KP__2_, AUX_IMF_2_. Optional: MMA_SHAi2C, MMA_SHA_2F, MIN_1DMi2_ |
Input Time Span |
Minimum of 4 months |
Spatial representation |
Spherical Harmonics up to degree 18 |
Time representation |
Snapshot models |
Units |
nT |
Resolution |
1 pT |
Uncertainty |
Refere to quality report |
Quality indicator |
Statistics of data misfit, power spectra etc. provided in validation report |
Data volume |
~10 kB |
Data format |
ASCII table [AD-15] |
Output Data |
Gauss coefficients |
Output time span and resolution |
Time span: Minimum 4 months
Time resolution: corresponding to 3 month knots separation and order 2 splines |
Update rate |
First after 4 month, afterwards update is three months (if granted by data quality). |
Latency |
1 week |
Notes |
Assumed updated rate is three month |
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? L2 Cat-1: MCO_SHA_2X
Product identifier |
MCO_SHA_2X |
Definition |
Spherical harmonic model of the main (core) field and its temporal variation |
Input Data |
MAGx_LR_1B, AUX_DST_2_, AUX_KP__2_, AUX_IMF_2_, AUX_OBS_2_ |
Input Time Span |
Minimum of 4 months |
Spatial representation |
Spherical Harmonics up to degree 18 |
Time representation |
Snapshot models |
Units |
nT |
Resolution |
1 pT |
Uncertainty |
|
Quality indicator |
|
Data volume |
~10 kB |
Data format |
ASCII table [AD-15] |
Output Data |
Gauss coefficients |
Output time span and resolution |
Time span: Minimum 4 months
Time resolution: corresponding to 3 month knots separation and order 2 splines |
Update rate |
First after 4 month, afterwards update is three months (if granted by data quality). |
Latency |
1 week |
Notes |
Assumed updated rate is three month
More information can be found at
http://www.spacecenter.dk/files/magnetic-models/CHAOS-6/
|
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Lithospheric Field
? L2 Cat-1: MLI_SHA_2C
Product identifier |
MLI_SHA_2C |
Definition |
Spherical harmonic model of the lithospheric field |
Input Data |
MLI_SHAi2C, MLI_VAL_2_ |
Input Time Span |
All available quiet time observations from the mission |
Spatial representation |
Spherical Harmonics from degree 16 to 150 |
Time representation |
Snapshot |
Units |
nT |
Resolution |
1 pT |
Uncertainty |
Refer to product quality report |
Quality indicator |
Statistics of data misfits provided in validation report |
Data volume |
~0.5 MB |
Data format |
ASCII table (SHC) [AD-15] |
Output Data |
Gauss coefficients |
Output time span |
N/A (lithospheric field is considered constant over the analysed time range) |
Update rate |
First after 1 year, updated every year |
Latency |
1.5 months |
Notes |
|
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? L2 Cat-1: MLI_SHA_2D
Product identifier |
MLI_SHA_2D |
Definition |
Spherical harmonic model of the lithospheric field |
Input Data |
MLI_SHAi2D, MLI_VAL_2_ |
Input Time Span |
One to four years of full Swarm data set |
Spatial representation |
Spherical Harmonics from degree 16 to 150 |
Time representation |
Snapshot |
Units |
nT |
Resolution |
1 pT |
Uncertainty |
Refer to product quality report |
Quality indicator |
Statistics of data misfits provided in validation report |
Data volume |
~0.5 MB |
Data format |
ASCII table (SHC) [AD-15] |
Output Data |
Gauss coefficients |
Output time span |
N/A (lithospheric field is considered constant over the analysed time range) |
Update rate |
One model every year |
Latency |
One month |
Notes |
|
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? L2 Cat-1: 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 |
|
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? L2 Cat-1: 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 |
|
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? L2 Cat-1: MLI_VAL_2_
Product identifier |
MLI_VAL_2_ |
Definition |
Comparison validation report for lithospheric field model |
Input Data |
MLI_SHA_2C, MLI_SHA_2D, MLI_SHA_2E, MLI_VAL_2C, MLI_VAL_2D, MLI_VAL_2E, AUX_LIT_2_ |
Data volume |
< 1 Mb per day |
Data format |
PDF |
Output Data |
PDF file |
Update rate |
Each time both, MLI_SHA_2C , MLI_SHA_2D and MLI_SHA_2D have been released |
Latency |
1 month |
Notes |
|
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Mantle Conductivity
? L2 Cat-1: MIN_1DM_2_
Product identifier |
MIN_1DM_2_ |
Definition |
1-D model of mantle conductivity |
Input Data |
MIN_1DMi2_, MC1_VAL_2_ |
Input Time Span |
2 years |
Spatial representation |
Conductivity distribution with respect to depth (1-D layered model of the Earth) |
Time representation |
N/A |
Units |
Kilometers (for layer radii), Siemens per meter (for conductivities) |
Resolution |
N/A |
Uncertainty |
Refer to product quality report |
Quality indicator |
N/A |
Data volume |
A few Kb |
Data format |
ASCII listing [AD-15] |
Output Data |
Conductivities within the layer, and radii of the top of the layer |
Output time span |
N/A |
Update rate |
First version after 2 years, update every year |
Latency |
1 month |
Notes |
This 1-D model is foreseen as the output of the 1-D frequency domain inversion |
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? L2 Cat-1: MCR_1DM_2_
Product identifier |
MCR_1DM_2_ |
Definition |
Global 1D C-responses |
Input Data |
MCR_1DMi2_, MC1_VAL_2_ |
Input Time Span |
2 years |
Spatial representation |
N/A |
Time representation |
N/A |
Units |
km |
Resolution |
N/A |
Uncertainty |
Refer to product quality report |
Quality indicator |
Uncertainties and squared coherencies coming from signal processing |
Data volume |
A few Kb |
Data format |
ASCII listing [AD-15] |
Output Data |
C-responses (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 |
|
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? L2 Cat-1: 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 |
|
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? L2 Cat-1: MC1_VAL_2_
Product identifier |
MC1_VAL_2_ |
Definition |
Validation report for 1D C-response |
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 |
|
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External Current Systems
? L2 Cat-1: 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 |
Root-mean-square difference between models and input data (after processing to subtract non-magnetospheric 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 time-instant 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; root-mean-square 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 |
|
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? L2 Cat-1: 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 |
|
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? L2 Cat-1: MMA_SHA_2F
Product identifier |
MMA_SHA_2F |
Definition |
Spherical harmonic representation of the large scale magnetospheric field and its induced counterpart |
Input data |
MAGx_LR_1B, AUX_IGR_2_, AUX_COR_2_, MCO_SHA_2F, MCO_SHA_2C, MCO_SHA_2D, AUX_LIT_2_, MLI_SHA_2C, MIO_SHA_2C, AUX_F10_2_, AUX_IMF_2F, AUX_DST_2_, AUX_KP__2_, AUX_OBS_2_ |
Input time span |
Full Swarm data set covering at least 30 days |
Spatial representation |
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 |
Root-mean-square 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 |
Root-mean-square difference between models and input data (after processing to subtract non-magnetospheric 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 time-instant 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 time-series is shorter than 1-year 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; root-mean-square 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 |
|
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? L2 Cat-1: 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 |
Data volume |
~130 kB |
Data format |
ASCII listing [AD-15] |
Output data |
Coefficients of SH model in dipole coordinates, with seasonal and diurnal periodicity |
Output time span |
N/A |
Update rate |
First after 1 year, updated every year |
Latency |
1.5 months |
Notes |
|
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? L2 Cat-1: MIO_SHA_2D
Product identifier |
MIO_SHA_2D |
Definition |
Spherical harmonic representation of the daily geomagnetic variations at mid and low latitudes (Sq and EEJ) |
Input data |
MIO_SHAi2D, MIO_VAL_2_ |
Input time span |
3 months to 1 year, to be confirmed and aligned to update rate |
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 fT |
Uncertainty |
Refer to product quality report |
Quality indicator |
Statistics of data misfits provided in the validation report |
Data volume |
~ 3.5 Mo' |
Data format |
ASCII listing [AD-15] |
Output data |
Coefficients of SH model in dipole coordinates, with seasonal and diurnal periodicity |
Output time span |
N/A |
Update rate |
First after 6 months, 1 year, and update every year |
Latency |
1.5 months |
Notes |
|
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? L2 Cat-1: MIO_VAL_2C
Product identifier |
MIO_VAL_2C |
Definition |
Validation report for ionospheric field model from CI chain |
Input data |
MIO_SHAi2C, MIO_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 |
|
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? L2 Cat-1: MIO_VAL_2D
Product identifier |
MIO_VAL_2D |
Definition |
Validation report for ionospheric field model from dedicated chain |
Input data |
MIO_SHAi2D, MIO_VALi2D |
Data volume |
< 1 Mb per day |
Data format |
PDF |
Output data |
PDF file |
Update rate |
First after 6 months, 1 year, and update every year |
Latency |
1 month |
Notes |
|
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? L2 Cat-1: MIO_VAL_2_
Product identifier |
MIO_VAL_2_ |
Definition |
Comparison validation report for ionospheric field model |
Input data |
MIO_SHA_2C, MIO_SHA_2D, MIO_VAL_2C, MIO_VAL_2D |
Data volume |
< 1 Mb per day |
Data format |
PDF |
Output data |
PDF file |
Update rate |
Each time when both, MIO_SHA_2C and MIO_SHA_2D are released. |
Latency |
1 month |
Notes |
|
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? L2 Cat-2: IBIxTMS_2F
Product identifier |
IBIxTMS_2F |
Definition |
Ionospheric bubble index |
Input data |
MAGx_LR_1B, EFIx_PL_1B, Satellite positions, Time stamps (UTC), AUX_IGR_2F, AUX_COR_2F, AUX_LIT_2F, AUX_PMF_2F, AUX_F10_2F, AUX_DST_2F, AUX_IMF_2F, AUX_SWV_2F, AUX_PSM_2F, AUX_PGM_2F |
Input time span |
3 days |
Spatial representation |
One index per data point (characterising whether the magnetic observation is affected by bubble or not.) |
Time representation |
1s time series |
Units |
N/A |
Resolution |
N/A |
Uncertainty |
N/A |
Quality indicator |
Flags_Bubble:
0 |
Quiet |
1 |
Confirmed plasma bubble |
2 |
Unconfirmed plasma bubble |
4 |
Large peak in unfiltered magnetic field residuals |
8 |
Time gap |
16 |
Too many peaks in filtered magnetic field residuals |
32 |
Outside equatorial orbit segment or invalid latitude/local time |
Flags_B, Flags_F and Flags_q provided in [AD-5].
|
Data volume |
~4 MB/day/satellite |
Data format |
CDF
Variable Name |
Description |
Type |
Units |
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 |
Bubble_Index |
Plasma Bubble Index
0 |
Quiet |
1 |
Bubble |
-1 |
Not analyzed |
|
CDF_INT2 |
No unit |
Bubble_Probability |
Detection probability of the plasma bubble
0 |
not probabale |
1 |
very probable |
The bubble probability is set to 0 by default for all data with a Flags_Bubble value of 32. The accuracy of the bubble probability is 0.2.
|
CDF_DOUBLE |
No unit |
Flags_Bubble |
Flags related to the plasma bubble index |
CDF_UINT1 |
No unit |
Flags_F |
Flags_F passed through from MAGx_L1_B |
CDF_UINT1 |
No unit |
Flags_B |
Flags_B passed through from MAGx_L1_B |
CDF_UINT1 |
No unit |
Flags_q |
Flags_q passed through from MAGx_L1_B |
CDF_UINT1 |
No unit |
|
Output data |
CDF file with time series |
Output time span |
1 day |
Latency |
6 min |
Update rate |
1 per day |
Notes |
|
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? L2 Cat-2: TECxTMS_2F
Product identifier |
TECxTMS_2F |
Definition |
Time series of the ionospheric total electron content |
Input data |
GPS RINEX observation and navigation files (GPSX_RO_1B), Swarm satellite ephemeris (MODX_SC_1B) GPS and Swarm satellite ephemeris (AUX_GPSEPH) GPS transmitter biases(AUX_DCB_2F) Leap seconds (AUX_USLEAP) |
Input time span |
3 days |
Spatial representation |
Line representation of GPS –Swarm link |
Time representation |
1-s time series for TEC and 1 day for DCB |
Units |
TECU (1016 electrons/m2) |
Resolution |
1E-8 TECU |
Uncertainty |
2 TECU |
Quality indicator |
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 |
km |
GPS_Position |
X-,Y-,Z-coordinates (WGS84) of the GPS satellite |
CDF_DOUBLE |
km |
LEO_Position |
X-,Y-,Z-coordinates (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 signal-to-noise ratio or raw signal strength on L1 |
CDF_DOUBLE |
No Unit |
S2 |
GPS signal-to-noise ratio or raw signal strength on L2 |
CDF_DOUBLE |
No Unit |
Absolute_STEC |
Absolute slant TEC |
CDF_DOUBLE |
TECU |
Absolute_VTEC |
Absolute vertical TEC |
CDF_DOUBLE |
TECU |
Elevation-Angle |
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 10-s (0.1 Hz) to 1-s (1 Hz) at:
-
2014-07-14 06:42:59 for Swarm A
-
2014-07-14 06:06:46 for Swarm B
-
2014-07-14 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°.
|
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? L2 Cat-2: FAC_TMS_2F
Product identifier |
FAC_TMS_2F |
Definition |
Time series of field-aligned and radial current densities along the orbit using the dual-satellite method. Field-aligned current (FAC) density is derived by the multiplication of the radial current (IRC) density with the inclination angle of the geomagnetic field. The field-aligned 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 ?>86° (near poles), where both FAC and IRC values are set to NaN.
Note that the magnetic field data used for the dual-satellite method is low-pass filtered with a 3-dB 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.
|
Input data |
MAGA_LR_1B, MAGC_LR_1B, Time stamps (UTC), AUX_IGR_2F, AUX_COR_2F, AUX_LIT_2F, AUX_PMF_2F, AUX_F10_2F, AUX_DST_2F, AUX_IMF_2F, AUX_SWV_2F, AUX_PSM_2F, AUX_PGM_2F |
Input time span |
3 days |
Spatial representation |
Current density estimates along entire orbits at positions between SwA and SwC |
Time representation |
Time series of current density, ?t=1sec |
Units |
Current density: µA/m2 |
Resolution |
Current density: 1E-6 µA/m2 |
Uncertainty |
50 nA/m2 for periods 10s to 90min on top of constant bias of <200nA/m2, 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 FAC-dual (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 FAC-dual N can be equal to 1, 2, 3, or 4.
Digit-Nr. |
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 FAC-dual, this digit is equal to 1 if latitude |?| >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 [AD-5].
|
Data volume |
5 MB per day |
Data format |
CDF
Variable Name |
Data Type |
Descriptions |
Units |
Timestamp |
CDF_EPOCH |
Time, UTC |
milli-seconds |
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/m2 |
IRC_Error |
CDF_DOUBLE |
uncertainty of IRC |
µA/m2 |
FAC |
CDF_DOUBLE |
Field-aligned current (FAC) |
µA/m2 |
FAC_Error |
CDF_DOUBLE |
uncertainty of FAC |
µA/m2 |
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 |
|
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? L2 Cat-2: FACxTMS_2F
Product identifier |
FACxTMS_2F |
Definition |
Time series of field-aligned and radial current densities along the orbit from single satellite measurements. Field-aligned current (FAC) density is derived by the multiplication of the radial current (IRC) density with the inclination angle of the geomagnetic field. The field-aligned 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. |
Input data |
MAGx_LR_1B, Satellite positions, Time stamps (UTC), AUX_IGR_2F, AUX_COR_2F, AUX_LIT_2F, AUX_PMF_2F, AUX_F10_2F, AUX_DST_2F, AUX_IMF_2F, AUX_SWV_2F, AUX_PSM_2F, AUX_PGM_2F |
Input time span |
3 days |
Spatial representation |
Current density estimates along entire orbits at positions of SwA, SwB, and SwC. |
Time representation |
Time series of current density, ?t=1sec |
Units |
Current density: µA/m2 |
Resolution |
Current density: 1E-6 µA/m2 |
Uncertainty |
less than FAC_TMS_2F, 70 nA/m2 on top of constant bias of <200nA/m2, 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 FAC-single (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 FAC-single N can be equal to 1 or 2.
Digit-Nr. |
Value |
Meaning |
1 |
0/N |
A short (< 5 seconds) data gap occurred, which was interpolated linearly |
2 |
0 |
For FAC-single, 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 FAC-single, 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 [AD-5].
|
Data volume |
5MB per day, per satellite |
Data format |
CDF
Variable Name
|
Data Type |
Descriptions |
Units |
Timestamp |
CDF_EPOCH |
Time, UTC |
milli-seconds |
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/m2 |
IRC_Error |
CDF_DOUBLE |
uncertainty of IRC |
µA/m2 |
FAC |
CDF_DOUBLE |
Field-aligned current (FAC) |
µA/m2 |
FAC_Error |
CDF_DOUBLE |
uncertainty of FAC |
µA/m2 |
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 |
|
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? L2 Cat-2: EEFxTMS_2F
Product identifier |
EEFxTMS_2F |
Definition |
Dayside equatorial electric field |
Input data |
MAGx_LR_1B, AUX_DST_2F, AUX_KP__2F , AUX_F10_2F, AUX_IGR_2F, AUX_COR_2F, AUX_LIT_2F, AUX_PMF_2F, AUX_PSM_2F, AUX_PGM_2F, AUX_IRZ_2F |
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 |
milliseconds elapsed since 00:00:00 January 1, 2000 UTC |
Milliseconds |
longitude |
CDF_DOUBLE |
Geographic longitude of satellite crossing of the magnetic equator |
Degrees |
latitude |
CDF_DOUBLE |
Geographic latitude of satellite crossing of the magnetic equator |
Degrees |
EEF |
CDF_DOUBLE |
Estimate of the equatorial electric field |
V/m |
RelErr |
CDF_DOUBLE |
Quality indicator of EEF estimate; relative error between modeled and observed current profile |
N/A |
flags |
CDF_UINT2 |
Flags describing data gaps and satellite identification
Bit |
Description |
1 |
EEF estimate came from Swarm satellite A data |
2 |
EEF estimate came from Swarm satellite B data |
3 |
EEF estimate came from Swarm satellite C data |
4 |
Processor failed due to a too large data gap in the Level 1b input data |
|
N/A |
|
Output data |
CDF file with time series
|
Output time span |
Continuous for entire mission. One value for each day-side equator crossing (90 minute sampling for day-night local time orbits, 45 minutes for dawn-dusk orbits) |
Update rate |
One output file per day |
Latency |
20 minutes |
Notes |
|
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? L2: IPDxIRR_2F
Product identifier |
IPDxIPR_2F |
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 ground-based 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 |
milli-seconds |
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; non-zero 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 level-2 Ionospheric Bubble Index product, IBIxTMS_2F |
- |
Ionopshere_region_ flag |
CDF_INT4 |
0: equator, 1: mid-latitudes; 2: auroral oval; 3: polar cap |
- |
IPIR_index |
CDF_INT4 |
0-3 low, 4-5 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 |
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Precise Orbit Determination
? L2 Cat-1: SP3xCOM_2_
Product identifier |
SP3xCOM_2_ |
Definition |
Time series of dynamic position and velocity of the center of mass of each satellite in the ITRF (Earth-fixed) frame |
Input Data |
GPSA_RO_1B, GPSB_RO_1B, GPSC_RO_1B, STRAATT_1B, STRBATT_1B, STRCATT_1B, MODA_SC_1B, MODB_SC_1B, MODC_SC_1B, SC_xDYN_1B, External data from IGS, IERS, CODE |
Input Time Span |
30 hr (daily batches with overlap) |
Spatial representation |
N/A |
Time representation |
GPS time (seconds – s), time step = 10 s |
Units |
km for position, dm/s for velocity |
Resolution |
1 ps for time, mm for position, 0.1 µm/s for velocity |
Uncertainty |
10 cm 3D for position |
Quality indicator |
Validation report SP3xVAL_2_ |
Data volume |
< 2 Megabyte (MB) per satellite per day |
Data format |
SP3c [AD-15] |
Output Data |
SP3c file |
Output time span |
24 hr |
Update rate |
Daily |
Latency |
21 days |
Notes |
Central 24 hr of input time span will be selected for SP3 product
Quality report will be provided as separate Level 2 product
|
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? L2 Cat-1: SP3xKIN_2_
Product identifier |
SP3xKIN_2_ |
Definition |
Time series of kinematic position of the center of mass of each satellite in the ITRF (Earth-fixed) frame |
Input Data |
GPSA_RO_1B, GPSB_RO_1B, GPSC_RO_1B, STRAATT_1B, STRBATT_1B, STRCATT_1B, MODA_SC_1B, MODB_SC_1B, MODC_SC_1B, SC_xDYN_1B, External data from IGS, IERS, CODE |
Input Time Span |
30 hr (daily batches with overlap) |
Spatial representation |
N/A |
Time representation |
GPS time (seconds – s), observation epochs |
Units |
km for position, dm/s for velocity |
Resolution |
1 ps for time, mm for position, 0.1 µm/s for velocity |
Uncertainty |
10 cm 3D for position |
Quality indicator |
Validation report SP3xVAL_2_ |
Data volume |
< 15 Megabyte (MB) per satellite per day |
Data format |
SP3c [AD-15] |
Output Data |
SP3c file |
Output time span |
24 hr |
Update rate |
Daily |
Latency |
21 days |
Notes |
Central 24 hr of input time span will be selected for SP3 product
Quality report will be provided as separate Level 2 product
|
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? L2 Cat-1: 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 |
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? L2 Cat-1: ACCxPOD_2_
Product identifier |
ACCxPOD_2_ |
Definition |
Time series of non-gravitational accelerations obtained by POD |
Input data |
SP3xCOM_2_, 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/s2 |
Resolution |
64 bit double precision floating point number format |
Uncertainty |
10-7 m/s2 variance for along-track and cross-track 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/s2 |
Estimated non-gravitational accelerations (X,Y,Z) |
|
Output data |
CDF file with time series of accelerations |
Output time span |
24 hr |
Update rate |
1 day |
Latency |
21 days |
Notes |
Version 0201 data is computed from GPS data using a Kalman filter approach. The reduced-dynamic orbit is used as a priori reference orbit. The level 1B accelerometer files are only used for spacecraft mass and CoG information
|
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Accelerometry
? L2 Cat-1: ACCxCAL_2_
Product identifier |
ACCxCAL_2_ |
Definition |
Time series of corrected and calibrated acceleration, including all corrections and calibration parameters |
Input data |
ACCx_PR_1B, ACCxPOD_2_, ACCxDISi2_, SC_xDYN_1B, ACCx_PR_1B |
Input time span |
24 h |
Spatial representation |
Three-dimensional time series along satellite orbit |
Time representation |
UTC |
Units |
m/s2 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/s2 for along-track 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/s2 |
Calibrated linear acceleration (X,Y,Z) |
a_stp |
CDF_REAL8 |
3 |
m/s2 |
Step correction for linear accelerations |
a_tmp |
CDF_REAL8 |
3 |
m/s2 |
Temperature correction for linear accelerations |
a_gg |
CDF_REAL8 |
3 |
m/s2 |
Gravity gradient correction for linear accelerations |
a_aa |
CDF_REAL8 |
3 |
m/s2 |
Angular acceleration correction for linear accelerations |
a_ca |
CDF_REAL8 |
3 |
m/s2 |
Centrifugal acceleration correction for linear accelerations |
s |
CDF_REAL8 |
3 |
N/A |
Scale factor (time series) for linear accelerations |
b |
CDF_REAL8 |
3 |
m/s2 |
Bias for linear accelerations |
spike_index |
CDF_REAL8 |
3 |
m/s2 |
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 (x-direction is roughly along-track, y-direction is roughly cross-track, z-direction is roughly nadir)
Calibration was performed against non-gravitational accelerations from POD that are contained in product ACCxPOD_2_
Preliminary bias will be replaced by final bias in aerodynamic accelerations in product ACCx_AE_2_
|
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? L2 Cat-1: ACCxVAL_2_
Product identifier |
ACCxVAL_2_ |
Definition |
Validation report for measured, modeled and POD accelerations ACCxCAL_2_, ACCxDISi2_ |
Input data |
ACCxDISi2_, ACCxCAL_2_, ACCxPOD_2_, SC_xDYN_1B_, ACCx_PR_1B_, MODx_SC_1B_ |
Input time span |
Variable |
Data volume |
– 10 MB / day |
Output data |
PDF |
Output time span |
Variable |
Update rate |
3 months |
Latency |
1 month |
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Magnetic Forcing of the Upper Atmosphere
? L2 Cat-1: ACCx_AE_2_
Product identifier |
ACCx_AE_2_ |
Definition |
Time series of calibrated accelerometer data, pre-processed to represent external non-gravitational forces and aerodynamic accelerations |
Input data |
SC_xDYN_1B, STRxATT_1B, SP3xCOM_2_, ACCxCAL_2_, ACCxPOD_2_, AUX_F10_2_, AUX_KP__2_, External data from IERS |
Input time span |
24 hr |
Spatial representation |
Time-series 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 |
nm/s2 for accelerations, s for time, m for altitude, degrees for latitude, longitude, hours for local solar time |
Resolution |
64 bit double precision floating point number format |
Uncertainty |
N/A |
Quality indicator |
Validation report TDAxVAL_2_ |
Data volume |
< 10 Mbyte per satellite per day |
Data format |
CDF
Field name |
Type |
Dimension |
Unit |
Contents |
time |
CDF_EPOCH |
1 |
ms |
Observation time |
acc_total_obs |
CDF_REAL8 |
1 |
m/s2 |
Non-gravitational acceleration from accelerometer and GPS receiver (X ˜ along-track) |
acc_ro_obs |
CDF_REAL8 |
1 |
m/s2 |
Aerodynamic accelerations (X ˜ along-track) |
|
Output data |
CDF file with time series |
Output time span |
24 hr |
Update rate |
1 day |
Latency |
21 days |
Notes |
The applied accelerometer bias and scale factors are available in the metadata. |
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? L2 Cat-1: DNSxPOD_2_
Product identifier |
DNSxPOD_2_ |
Definition |
Thermospheric density at the satellite location along with auxiliary parameters (altitude, latitude, longitude and local solar time). Derived from non-gravitational accelerations based on precise orbit determination data only (ACCxPOD_2_) |
Input data |
MODx_SC_1B, STRxATT_1B, SC_xDYN_1B, ACCx_FMi2_, GPSx_RO_1B, ACCxPOD_2_ |
Input time span |
24 hr |
Spatial representation |
Time-series 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/m3 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/m3 |
Density derived from GPS accelerations |
density_orbitmean |
CDF_REAL8 |
1 |
kg/m3 |
Orbit-average of density derived from GPS accelerations |
altitude |
CDF_REAL8 |
1 |
m |
Altitude |
latitude |
CDF_REAL8 |
1 |
deg |
Geodetic latitude |
longitude |
CDF_REAL8 |
1 |
deg |
Geodetic longitude |
|
Output data |
CDF file with time series |
Output time span |
24 hr |
Update rate |
1 day |
Latency |
21 days |
Notes |
The density data is derived from the ACCxPOD non-gravitational acceleration component along the spacecraft X-axis. The following processing steps have been performed:
- Modelled radiation pressure accelerations have been subtracted from the full non-gravitational accelerations, to arrive at aerodynamic accelerations. Because the Kalman filter approach results in a smoothed representation of true accelerations, the radiation pressure model output has been smoothed as well, in order to avoid density jump artefacts at eclipse transitions.
- The resulting aerodynamic accelerations are converted into densities, using an aerodynamic model based on a panelised representation of the satellite. The gas-surface interaction is based on diffuse reflection, and an energy accommodation coefficient of 0.93 is used.
- The densities are multiplied by a factor of 1.32, to compensate for the observed difference in scale between the panelised aerodynamic model, and an aerodynamic model based on a more accurate representation of the geometry of the Swarm satellites. The more accurate model will be implemented in a future updated version of the data.
- 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.
|
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? L2 Cat-1: DNSxACC_2_
Product identifier |
DNSxACC_2_ |
Definition |
Thermospheric density at the satellite location |
Input data |
STRxATT_1B, SC_xDYN_1B, ACCx_AE_2_, SP3_COM__2, AUX_IER_2_, AUX_AER_2_, AUX_F10_2_, AUX_KP__2_, External data from IERS |
Input time span |
24 hr |
Spatial representation |
Time-series 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/m3 for density, m/s for wind speed |
Resolution |
64 bit double precision floating point number format |
Uncertainty |
30% of variance from models for neutral density |
Quality indicator |
Validation report TDAxVAL_2_ |
Data volume |
< 15 Mbyte per satellite per day |
Data format |
CDF
Field name |
Type |
Dimension |
Unit |
Contents |
time |
CDF_EPOCH |
1 |
ms |
Observation time |
altitude |
CDF_REAL8 |
1 |
m |
Observation altitude |
latitude |
CDF_REAL8 |
1 |
deg |
Observation geodetic latitude |
longitude |
CDF_REAL8 |
1 |
deg |
Observation geodetic longitude |
local_solar_time |
CDF_REAL8 |
1 |
s |
Observation local solar time |
density |
CDF_REAL8 |
1 |
kg/m3 |
Thermospheric neutral density |
|
Output data |
CDF file with time series |
Output time span |
24 hr |
Update rate |
1 day |
Latency |
21 days |
Notes |
|
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Gravity Field
? L2 Cat-1: EGF_SHA_2_
Product identifier |
EGF_SHA_2_ |
Definition |
Monthly gravity field of the Earth |
Input data |
GPSA_RO_1B, GPSB_RO_1B, GPSC_RO_1B, STRAATT_1B, STRBATT_1B, STRCATT_1B |
Input time span |
1 calendar month |
Spatial representation |
Spherical harmonic coefficients |
Time representation |
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 1-2 mm geoid height or 1-2 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 long-term trend, annual and semi-annual variations estimated from monthly un-weighted averages of numerous GRACE models (AIUB02, CSR05, GRGS03, ITSG14, GFZ05a, JPL05 and TNJ01) |
Data volume |
20 Kb |
Data format |
ASCII file with Stokes Coefficients following the ICGEM-format (http://icgem.gfz-potsdam.de/ICGEM-Format-2011.pdf) |
Output data |
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 signal-to-noise ratio drops below 1 at those degrees and above
- Further product details in Swarm ITT1.1 TN-01
|
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Processing Chains of Level 2 Products
Figure 1: L2 chain
Figure 2: L2 processing chains which result in magnetic L2 products
Figure 3: L2 processing chains that result in precise orbits and thermosphere L2 products
Figure 4: L2 processing chains related to the Earth environment and space weather (Cat-2 products)
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