Frequently Asked Questions for ROC users.

Table of content

Questions related to the RPW data processing at LESIA

What are the RPW data products ?

A list of the RPW data produced by the ROC at LESIA is available in RPW Data Products.

The description of the RPW data products can be found  in https://issues.cosmos.esa.int/solarorbiterwiki/display/SOSP/Archive+Support+Data

Standards and metadata definitions for the RPW science data are presented in https://issues.cosmos.esa.int/solarorbiterwiki/display/SOSP/Metadata+Definition+for+Solar+Orbiter+Science+Data

Where I can find the RPW data produced by the ROC at LESIA ?

RPW public data are available with a 90-days latency from the Solar Orbiter Archive (SOAR) portal at ESAC (http://soar.esac.esa.int/soar/)

Copies of the RPW public data are also :


Preliminary RPW data file generated by the ROC at LESIA are saved within 48h in https://rpw.lesia.obspm.fr/roc/data/private/solo/rpw/data

Access to this site is restricted to authorized members only (see xavier.bonnin@obspm.fr for access).

What is the Common Data Format (CDF)?

The Common Data Format (CDF) is a file format designed by NASA and used to store Solar Orbiter In Situ payload data, including RPW.

More information about CDF can be found in https://cdf.gsfc.nasa.gov/.

Additional questions about RPW CDF can be found in RCS-related FAQ#relatedFAQ-CDF-relatedquestions.

What are the software used by the ROC to process RPW data?

The ROC relies on four pipelines to generate RPW data:

  • The RPW Operation and Data Pipeline (RODP) is the main pipeline run by the ROC at LESIA to generate RPW L0/L1/HK data products from downlinked telemetry
  • The RCS Interface Validation Pipeline (RIVP) is the pipeline used to validate and run the RPW Calibration Software (RCS)
  • The RPW Low Latency Data Pipeline (LLDP) is a the pipeline used to process the Low Latency data. The main instance of the LLDP is hosted and run by the Solar Orbiter SOC at ESAC (Madrid, Spain)
  • The ROC Ground Test SGSE (RGTS) is dedicated to parse RPW telemetry/command data as stored by ground MEB GSE and ADS GSE. (Mainly used during ground calibrations and tests)

What are the RPW Calibration Software (RCS)?

The RPW Calibration Software (RCS) are run by the ROC at LESIA to generate the RPW calibrated science data (L2).

The software are developed and maintained by the RPW Lead CoI Teams.

Questions related to the RCS can be found in RCS-related FAQ

What is the RPW Instrument Database (IDB)?

The RPW Instrument Database (IDB) is required to parse/generate RPW telemetry (TM) and commands (TC) binary packet data. The IDB is also contain the "raw" to/from "engineering" conversion of TM/TC parameter values.

Two versions of the IDB are used by the ROC to parse packets:

* "MIB" version: the Mission Information Base (MIB) is delivered by the Solar Orbiter MOC via GFTS and contains a copy of the operational IDB as well as the Solar Orbiter platform and payload TC sequences. Copies of the MIB source text files sent by the MOC are stored by the ROC in https://gitlab.obspm.fr/ROC/mib.

* "PALISADE" version: "internal" version of the RPW used by the RPW flight software team at LESIA. PALISADE IDB versions are stored in https://version-lesia.obspm.fr/repos/SO-RPW/IDB/tags/ (restricted access)


Questions related to ancillary data (orbit, attitude, time, etc.)

Where I can find a description of the ancillary data for Solar Orbiter?

Solar Orbiter ancillary data are described in the document "SOC-Provided Ancillary Data for Solar Orbiter" (SOL-SGS-TN-0017).

This document can be retrieved from https://issues.cosmos.esa.int/solarorbiterwiki/display/SOSP/SOC-Provided+Ancillary+Data+For+Solar+Orbiter

N.B. Ancillary data are mostly provided as SPICE kernels. Visit https://naif.jpl.nasa.gov/naif/ for more details about SPICE.

Where I can find the ancillary data (SPICE kernels) for Solar Orbiter?

The SPICE kernels for Solar Orbiter are made available by ESA in https://www.cosmos.esa.int/web/spice/solar-orbiter

Copies of latest SPICE kernels received by ROC are saved in https://rpw.lesia.obspm.fr/roc/data/private/solo/soc/spice/kernels/ (restricted access)

How to read Solar Orbiter SPICE kernels with Python?

ROC uses spiceypy Python module to handle SPICE kernels.

The easiest way to load all kernels in one shot is to use metakernels (mk). mk files are included in the SPICE kernels set in the mk/ folder.

There are two mk files used to load predicted data (solo_ANC_soc-pred-mk.tm) and as-flown data (solo_ANC_soc-flown-mk.tm).


import spiceypy

# Define paths to the MK files
predicated_mk_filepath = "solo_ANC_soc-pred-mk.tm"
asflown_mk_filepath = "solo_ANC_soc-flown-mk.tm"

# Predicated SPICE kernels should be loaded first
spiceypy.furnsh(predicated_mk_filepath)
# Then load as-flown SPICE kernels 
spiceypy.furnsh(asflown_mk_filepath)

# Print out the toolkit version
spicepy.tkvrsn("TOOLKIT")

# At this stage Solar Orbiter SPICE kernels have been loaded and are ready to be used (visit spiceypy documentation site in https://spiceypy.readthedocs.io to learn more about module capabilities.)


  • See here to find Solar Orbiter SPICE kernel description
  • See here to find Solar Orbiter SPICE kernels
  • ROC supplies a simple Python package spice_manager to easily load and perform basical operations with Solar Orbiter SPICE kernels
  • spiceypy is not officially supported by NAIF SPICE team

How to convert on-bord time (OBT) to UTC time?

The Solar Orbiter SOC Team provides information for translating on-board time to UTC time in https://issues.cosmos.esa.int/solarorbiterwiki/display/SOSP/Translate+from+OBT+to+UTC+and+back

N.B. You need SPICE kernels to perform convertion (see related question here)

How to retrieve Solar Orbiter orbit digest CDF files ?

The SOC provides CDF files that contain Solar Orbiter location and speed in HEE and HCI coordinate systems.

These files are made available in the SOC Public Confluence page (https://issues.cosmos.esa.int/solarorbiterwiki/)

A copy of these files are also saved by the LESIA in https://rpw.lesia.obspm.fr/roc/data/private/solo/soc/spice/cdf/ (restricted access)

Where is Solar Orbiter spacecraft currently?

You can use the "where is solar orbiter" ESA's tool for a quick look of spacecraft trajectory over the Sun.




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