2020/08/09 Updates to CDF L1 data structure

Due to Solar Orbiter metadata standard, some updates of L1 CDF files data structure were necessary.

Epoch

Epoch is now computed using spice kernel, from SCET coarse and fine time

Other time variables

Other time variables are now represented as CDF_REAL8, giving number of seconds of oncloard clock.

  • Replace SCET_coarse_time (CDF_UINT4) + SCET_fine_time (CDF_UINT2)

    with a single variable : SCET (CDF_REAL8)

  • Replace CCSDS_coarse_time (CDF_UINT4) + CCSDS_fine_time (CDF_UINT2)

    with a single variable CCSDS_time (CDF_REAL8)

Note

These modifications have been applied to all CDF L1 files

  • swa-pas-3d,

  • swa-pas-hsk,

  • swa-pas-mom,

  • swa-pas-cal

CDF L1 3D matrix description

In order to have the same description of PAS 3D distribution data in both L1 and L2 CDF files, we have decided to rename some support data variables in CDF L1 3D files.

  • Energy_table ⇒ Energy

  • Energy_delta_plus ⇒ delta_p_Energy

  • Energy_delta_minus ⇒ delta_m_Energy

  • CEM_table ⇒ Azimuth

  • CEM_delta ⇒ delta_Azimuth

  • Elevation_table ⇒ Elevation

  • Elevation_delta ⇒ delta_Elevation

L1 3D CDF files

Logical file ID

solo_L1_swa-pas-3d_yyyymmdd_Vxx.cdf

New CDF 3D data structure

Varname Size and Type Vary Description

Epoch

CDF_TIME_TT2000

Yes

Epoch encoded as Terrestrial Time on rotating Earth geoid, ns since J2000

Duration

CDF_FLOAT

Yes

Acquisition duration

CCSDS_time

CDF_REAL8

Yes

Elapsed time of the onboard clock at the time of data recording on SSMM

SCET

CDF_REAL8

Yes

Elapsed time on the onbloard clock at the start of acquisition time

SOURCE

CDF_UINT1

Yes

Source (0: Normal, 1: Snapshot, 2: Burst, 3: Trigger

SAMPLE

CDF_INT2

Yes

Current sample

NB_SAMPLE

CDF_INT2

Yes

Number of samples

FIRST_ENERGY

CDF_INT2

Yes

First energy bin

NB_ENERGY

CDF_INT2

Yes

Number energy bins

FIRST_ELEVATION

CDF_INT2

Yes

First elevation bin

NB_ELEVATION

CDF_INT2

Yes

Number elevation bins

FIRST_CEM

CDF_INT2

Yes

First CEM

NB_CEM

CDF_INT2

Yes

Number CEM

INFO

CDF_UINT1

Yes

Info

SCHEME

CDF_UINT1

Yes

Scheme

FULL_3D

CDF_UINT1

Yes

Full 3D

COMPRESSED

CDF_UINT1

Yes

Compressed data

MAX_CNT_ENERGY

CDF_INT2

Yes

Max count energy bin

MAX_CNT_ELEVATION

CDF_INT2

Yes

Max count elevation number

MAX_CNT_CEM

CDF_INT2

Yes

Max count CEM

NB_K

CDF_INT2

Yes

Number of sub-samping per second

K

CDF_INT2

Yes

Current sub-sampling

COUNTS

11 x 9 x 96 x CDF_UINT2

Yes

3D counts

Energy

96 x CDF_REAL4

No

Center of energy bins

delta_p_Energy

96 x CDF_REAL4

No

Energy bins delta plus values

delta_m_Energy

96 x CDF_REAL4

No

Energy bins delta minus values

Azimuth

11 x CDF_REAL4

No

Center of Azimuth bins (CEM)

delta_Azimuth

11 x CDF_REAL4

No

Azimuth bins half interval

Elevation

9 x CDF_REAL4

No

Center of elevation bins

delta_Elevation

9 x CDF_REAL4

No

Elevation bins half interval

Previous CDF 3D data structure

Varname Size and Type Vary Description

Epoch

CDF_TIME_TT2000

Yes

Epoch encoded as Terrestrial Time on rotating Earth geoid, ns since J2000

Duration

CDF_FLOAT

Yes

Acquisition duration

CCSDS_coarse_time

CDF_UINT4

Yes

CCSDS coarse time

CCSDS_fine_time

CDF_UINT2

Yes

CCSDS fine time

SCET_coarse_time

CDF_UINT4

Yes

SCET coarse time

SCET_fine_time

CDF_UINT2

Yes

SCET fine time

SOURCE

CDF_UINT1

Yes

Source (0: Normal, 1: Snapshot, 2: Burst, 3: Trigger

SAMPLE

CDF_INT2

Yes

Current sample

NB_SAMPLE

CDF_INT2

Yes

Number of samples

FIRST_ENERGY

CDF_INT2

Yes

First energy bin

NB_ENERGY

CDF_INT2

Yes

Number energy bins

FIRST_ELEVATION

CDF_INT2

Yes

First elevation bin

NB_ELEVATION

CDF_INT2

Yes

Number elevation bins

FIRST_CEM

CDF_INT2

Yes

First CEM

NB_CEM

CDF_INT2

Yes

Number CEM

INFO

CDF_UINT1

Yes

Info

SCHEME

CDF_UINT1

Yes

Scheme

FULL_3D

CDF_UINT1

Yes

Full 3D

COMPRESSED

CDF_UINT1

Yes

Compressed data

MAX_CNT_ENERGY

CDF_INT2

Yes

Max count energy bin

MAX_CNT_ELEVATION

CDF_INT2

Yes

Max count elevation number

MAX_CNT_CEM

CDF_INT2

Yes

Max count CEM

NB_K

CDF_INT2

Yes

Number of sub-samping per second

K

CDF_INT2

Yes

Current sub-sampling

COUNTS

11 x 9 x 96 x CDF_UINT2

Yes

3D counts

Energy_table

96 x CDF_REAL4

No

Cenetr of energy bins

Energy_delta_plus

96 x CDF_REAL4

No

Energy bins delta plus values

Energy_delta_minus

96 x CDF_REAL4

No

Energy bins delta minus values

CEM_table

11 x CDF_REAL4

No

Center of CEM bins

CEM_delta

11 x CDF_REAL4

No

CEM bin half interval

Elevation_table

9 x CDF_REAL4

No

Center of elevation bins

Elevation_delta

9 x CDF_REAL4

No

Elevation bin half interval

L2 3D CDF files

Logical file ID

solo_L1_swa-pas-3d-fdist_yyyymmdd_Vxx.cdf

CDF structure

Variable Sizes x type Vary Catdesc

Epoch

CDF_TIME_TT2000

Yes

Epoch encoded as Terrestrial Time on rotating Earth geoid, ns since J2000

Half_interval

CDF_REAL4

Yes

Acquisition period half interval

SCET

CDF_REAL8

Yes

Elapsed time on the onboard clock

start_energy

CDF_INT2

Yes

Start energy bin

nb_energy

CDF_INT2

Yes

Number energy bins

start_elevation

CDF_INT2

Yes

Start elevation bin

nb_elevation

CDF_INT2

Yes

Number elevation bins

start_CEM

CDF_INT2

Yes

Start CEM

nb_CEM

CDF_INT2

Yes

Number CEM

nb_K

CDF_INT2

Yes

Number of sub-samping per second

K

CDF_INT2

Yes

Current sub-sampling

fdist

11 x 9 x 96 x CDF_REAL4

Yes

Distribution function

Energy

96 x CDF_REAL4

No

Center of energy bins

delta_p_Energy

96 x CDF_REAL4

No

Delta plus energy bins

delta_m_Energy

96 x CDF_REAL4

No

Delta minus energy bins

Azimuth

11 x CDF_REAL4

No

Center of CEM bins (azimuth)

Elevation

9 x CDF_REAL4

No

Center of elevation bins

delta_Azimuth

11 x CDF_REAL4

No

Delta Atimuth (CEM)

delta_Elevation

9 x CDF_REAL4

No

Delta elevation table

FULL_EN_TABLE

11 x 9 x 96 x CDF_REAL4

No

Full definition energy table

FULL_AZ_TABLE

11 x 9 x 96 x CDF_REAL4

No

Full definition azimuth table

FULL_EL_TABLE

11 x 9 x 96 x CDF_REAL4

No

Full definition elevation table